Taperssection.com
Gear / Technical Help => Microphones & Setup => Topic started by: Gutbucket on January 15, 2024, 01:12:34 PM
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Continued from part 3..
OMT Part 1 thread- http://taperssection.com/index.php?topic=96009.msg1279052#msg1279052
OMT Part 2 thread- https://taperssection.com/index.php?topic=184876.msg2251211#msg2251211
OMT Part 3 thread- https://taperssection.com/index.php?topic=191953.msg2311359#msg2311359
Will edit this 1st post to add appropriate links as the thread grows.
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(reserved)
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Ok, back to discussion of the configuration of the L/R near-spaced pair and its role. I started this post before the discussion of the Improved 3-point PAS at the end of the previous thread, but pushed it off to the start off the new thread, since it sort of recaps a lot of how OMT developed up to this point. I intend to start a new thread on Improved 3-point PAS to split it off from this more esoteric OMT discussion, or may just append the existing 2-point Improved PAS thread(s).
[snip..]
Ah, I understand now! I was misinterpreting +/-45° to mean 45° ± Nº (and therefore wondering what range of N to expect) but I realize now you mean +45° on one side and -45º on the other for a total angle of 90° fixed. Thank you.
Yes, that's it. A few more thoughts on that in my next post..
Several things going on there. The imaging relationship across L/C/R mic positions is one. An improved sense of clarity, proximity, and "upfront impact and bigness" (to my ear, for lack of better description) is another. The problem is that fully optimizing for one becomes at odds with optimizing for the other. Over time I've worked on improving the second without overly compromising the first, and I feel this points to a potential convergence between Improved 3-point PAS and OMT I mentioned at the end of the previous thread.
Where this came from (bear with me though a bit of historical progression of OMT)-
I found I gained a lot of flexibility using three mics instead of two, largely because it allows for three new forms of balance control unavailable with just two mic channels: Level of the center verses both sides, slight panning adjustments of the center without affecting the sides, and when needed, the ability to push the L/R energy balance to one side while panning the center the opposite way to compensate. All things that can be very helpful in the real world of concert taping. I gained the ability to separate the control of energy distribution and center image position to a limited but useful extent. Originally this was 3 omnis in mounted in spheres, later a directional mic between two omnis, sometimes 3 directional mics when indoors. That's 3 ignoring the rear-facing channel or mono SBD in making full use of a 4 channel recorder.
I later increased channel count from 4 to 6 channels by adding Left/Right directional mics between the center mic and the wide omnis, and looked into a number of ways of doing that, trying a few different approaches at my favorite outdoor amphitheater. Günther Thiele's OCT (Optimum Cardioid Triangle) arrangement made a lot of sense to me and I found it worked best for playback over three front speakers, which was my primary focus at the time, but also it worked better for 2ch playback. Ok good.
The imaging of OCT really does work astoundingly well over three front speakers, which it was originally designed specifically for by minimizing the overlap between the Left and Right mic patterns as much as possible, while retaining just the right of overlap with the Center pattern (not too much, nor too little) so as to hand off smoothly from one segment to the other without conflicting. It does that by using a cardioid in the center and leveraging the supercardioid pattern in such a way that the null of the fully sideways pointing (+90°) Left supercard is pointed directly at the Right edge of the recording angle, which is where the Right speaker will be during playback, and vice-versa. Pretty cool. In addition to that, sounds arriving from outside of the recording angle window are picked up by the rear-lobe of the opposite mic channel and therefore will be in antiphase, which is sort of like Blumlein. But unlike Blumlein, as the angle of arrival shifts farther around the sides and on toward the back, the signal into the opposite channel is picked up with much reduced less level due to the the reduced sensitivity of the rear lobe. That, along with the arrangement capturing phase / time-of-arrival information by being near-spaced, is unlike and arguably perceptually superior to Blumlein. Its a very clever 3 microphone arrangement.
So my initial OMT array incorporating six channels used an OCT center arrangement with fully sideways facing supercards. The primary difference between that OMT6 and OCT was the wider spaced omnis and the single rear facing channel. This worked really well for me outdoors, and much better than most tapers might expect indoors. I think the directly forward facing center mic anchoring everything, and the other mics being purposefully arranged to work well with it is a big reason why.
At some point I no longer had a good surround playback system setup, and was listening primarily in stereo. I still wanted to support excellent surround playback (done right its arguably better used for the replay of live concerts than for anything else), but was really listening most critically in stereo. First thing I tried was making the center mic more directional, then switched it to a Mid/Side pair. The change to a center coincident pair was all about optimizing 2ch stereo, it wasn't needed for surround. Recording using a 6 channel recorder required sacrificing the single rear-facing channel to do that. The addition of the coincident center pair worked great for all the reasons discussed at length in previous threads, but I missed the rear channel. I went back and forth about what was more important. Really, I wanted both. Recording 8 channels felt extreme but allowed me to do that.
Also, all this is primarily about general concert taping, and not so much classical music recording done in gorgeous sounding halls where the microphone array can be put in just the right place and shifted slightly until positioned just right. I wanted to better accommodate taper realities, while hopefully also improving things further in already good acoustic situations like nice sounding outdoor amphitheaters where it was already working well.
To do that I wanted the L/R directional pair angled more forward, rather than pointing directly sideways at either side wall (the omnis or side facing subcards cover that just fine). That change would impart some forward sensitivity bias into the geometry of the array itself, and not just have that forward bias entirely reliant on the level of the center channel in the mix. To achieve that that I shifted to using a more narrow supercardioid pattern in all three positions and used some additional L/R spacing to try and maintain a somewhat equivalent recording angle to OCT: Supercards in all three positions, a bit more spacing, and L/R angled reasonably forward. Left/Right at +/-45° is the result of this. Switching to a supercard center also helped a bit with clarity and a bit more reduction of audience noise in the center, arriving from elsewhere.
All of that was about increasing forward sensitivity in the L/R directional imaging mics while trying to preserve good imaging. Upon making the change I found the imaging remained good when listening in stereo. I began to wonder if I was getting too "belt and suspenders" with phase-correlated imaging being contributed by both the coincident center pair AND the near-spaced triplet. I found I could use either in the mix, and each provided somewhat different qualities. The L/C/R tended to be more focused and precise image-placement wise, with cleaner transients, but flatter and less dimensional. The M/S pair more phase-correlated, yet at the same time more ambient in its stereo width. I now typically balance both separately in the mix first, then go back and tweak the level of the Side channel while listening to everything in play. With the near-spaced L/R pair in there providing a lot of the L/R imaging information, I'm using the Side channel as sort of an "ambient width special sauce" type of thing. It may be more directionally accurate without it, but the right amount of it brings "the sound" that makes me smile and pulls me into the recording.
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Because it is directly related to the current topic of conversation, I'm cross posting here what I posted over in Voltronics Solution for time-aligning center mics.. (https://taperssection.com/index.php?topic=203948.msg2406488#msg2406488) thread this morning, along with a bit of further discussion of whats going on in relation to OMT arrays, and the evolution away from OCT:
Posted earlier in that thread:
The deeper question is what the ideal time-alignment is for the array you are using, and the location you are using it from. Its not necessarily all microphones sharing the same plane (as can be seen when playing with some of the multichannel visual imaging tools, or looking at William's multichannel stereozoom solutions). But if what is optimal is unknown, then all in one plane is most the logical thing to do.
Optimally managing time alignment and imaging is why the geometry my multichannel arrays tend to be wide with far less front/back dimension.. but some front/back dimension is frequently important and better than having all mics in the same left/right plane.
Followed this morning with this..
Back to add some additional detail about center mic alignment, feel free to skip this read if not interested in the technical side of all this-
The classic Decca tree arrangement is sort of a special case as it is essentially placed "inside" the ensemble, which more or less wraps around it. Sounds arrive at the array from a very wide angle, in essence converging in on it from a half-circle.
In contrast most tapers are dealing with sound arriving from farther out in front of the recording position, in more of a plane-wave like fashion (this is a gross simplification, but bear with it for the purpose of discussion). In that case, there are a couple things going on acoustically. One is the time-alignment of transient information. If we really were dealing with a plane-wave, an array of mics placed along a straight line with no forward spacing of the center position, oriented perpendicular to the wavefront arrival would capture it simultaneously in time in all channels. There would be no time arrival differences across channels. I think this is what most tapers have in mind when they think about time-aligning the center mic position. Plane waves arriving from directions other than directly in front will produce increasing time of arrival offsets, which will be greatest for a wavefront arriving from fully left or right (+/-90 degrees), as happens with any spaced pair.
Complicating that is the question of whether we really want full time alignment for that front arriving plane wave or not. Maybe we want to leverage human hearing cues by pinging the center mic position slightly ahead of the L/R positions to strongly anchor the center in a perceptual sense.
Another aspect is managing the imaging overlap between each pair of microphone channels. Two spaced microphones will produce a stereo recording angle that is related to the spacing between them (sensitivity pattern and mic angle also play a role, but ignore that for now). As the spacing between a pair of microphones is made larger, the stereo recording angle grows narrower, but it never actually reaches zero degrees - its edges always splay out wider than the spacing between microphones. So each pair of microphones produces its own imaging angle, the middle of which which is perpendicular to the line between those two microphones, and the edges of which are angled outward from that center perpendicular line. If we place all the microphones in a straight line, those outward angled edges will overlap each other. If we want the edges of each imaging segment to line up nicely with each other instead, so that they hand-off cleanly from one to the next, we need to introduce curvature to the array to angle each segment farther apart until the edges of each segment align. We can do that in a 3-position mic array by moving the center microphone position forward.
There are complications of course. Three microphone positions create not just two separate imaging segments but three. We might align the edges of the L-C and C-R imaging segments nicely by pushing the center mic position forward, but the separate L-R imaging segment is going to be considerably narrower than either (because those two microphones are spaced more widely), and will overlap them both. Leveraging pattern can help manage that. Additionally, it's possible to "steer" the imaging sector of each pair one way or another by carefully leveraging microphone position, time delay, and sensitivity pattern, making it possible to do so asymmetrically where required. The multichannel Willliams arrays use that technique, some of which require time-delay to get the sectors to line up properly.
It gets complicated! Not saying what's right or wrong here, just laying out what's going on and the ways in which it can be manipulated.
Minimizing any problems of overlap between the L/R imaging segment and the L/C-C/R imaging segments is what OCT achieves by orienting the L/R supercardioids 180° apart, and that management of overlap gets compromised when angling the L and R mic pair more forward. Spacing them farther apart to compensate for the change of angle helps correct the alignment of the L/C and C/R imaging sectors, yet at the same time increases the level of and aggravates the misalignment of the L/R sector with those imaging sectors. How much that matters is an open question I don't have a good answer for, but is one reason I've tended to go not narrower than +/-45° with the L/R pair.
Although I want everything working harmoniously, sufficient clarity and good direct/reverberant ratio are more critically important to me than good imaging. Because of that, perhaps the optimal solution is going to be improved 3-point PAS, which seeks to maximize clarity and d/r ratio first by pointing the microphones at the source, then secondarily seeks to optimize imaging by determining the spacing between mic positions based on PAS angle.
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A question related to all this that still lingers for me..
Given the important role of clarity, perceived proximity and "upfront bigness", which channels of the array are best used for providing those things?
While I still need to make a more proper comparison between the new stereo shotgun used in place of the center supercardioid M/S pair (by first equalizing each to best effect), upon initial listen I do seem to be getting nicely increased vocal clarity and proximity from the switch to the center shotgun, as posted about at the end of the last thread.
Yet as discussed, earlier I achieved improved clarity, proximity and upfront bigness by angling the near-spaced L/R par more forward. And that idea might be further extended to pointing the pair directly at the stacks and adjusting its spacing based on that angle (3-point Improved PAS),
So instead of using a shotgun in the center, maybe I should keep the center M/S pair as it was (supercardioid Mid instead of a shotgun) and use short shotguns in the near-spaced L/R positions, leveraging 3-point PAS.
And in that case, maybe the center Mid, being relieved of its up front vocal clarity duties, would be better as a cardioid.. or maybe go the other way and use three shotguns across L/C/R, which could allow for a tighter angle with somewhat less spacing between L and R, since that becomes problematic at narrow PAS angles.
Not sure what the right answer is. In thinking about this its interesting to frame the question in terms of what the array is supposed to be doing. I have been thinking of it as "spatially sampling" the acoustic environment, slicing it up into segments which I then use to either feed a surround playback system directly, which is more objective, recreating the illusion of the the sound-field in the room, but is also able to be manipulated via mix-down to 2-ch stereo, a playback format that is more subjective in recreating the illusion of the sound-field for reproduction over just two speakers or a pair of headphones, which may include binaural cues.
I sort of see using a center shotgun as leaning toward the more objective "spatial sampling" approach - the directional sensitivity of the array increases progressively moving around the array to front center, and efforts made to produce excellent 2-ch stereo playback from that is mostly done in post. Whereas I sort of see using two shotguns in the L/R PAS positions along with a less directional M/S pair in the center as leaning more toward building subjective/perceptual stereo-binaural cues into the array itself. I'll probably have to get surround playback operating again and so some critical listening to answer this question, by determining how multichannel surround playback is effected by what might only end up benefiting stereo playback.. if it does at all.
Thinking a bit out loud here, but doing so to establish some of the things I'm thinking about as part 4 of the thread gets rolling.
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A question related to all this that still lingers for me..
[snip]
And in that case, maybe the center Mid, being relieved of its up front vocal clarity duties, would be better as a cardioid.. or maybe go the other way and use three shotguns across L/C/R, which could allow for a tighter angle with somewhat less spacing between L and R, since that becomes problematic at narrow PAS angles.
Not sure what the right answer is.
Thinking a bit out loud here, but doing so to establishing some of the things I'm thinking about as part 4 of the thread gets rolling.
Thanks for sharing your thoughts, super interesting to reflect on.
Is there a "right" answer?
3 shotguns across reminds me of early 90s Dead shows, many folks running that setup using modified Naks. I remember liking some outdoor recordings, but indoor venues not so much. I think it's b/c those shotguns had cruddy off-axis response and didn't do well with the reflected waves. How is off-axis on your stereo shotgun?
Cheers
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How is off-axis on your stereo shotgun?
At least in the handful of recordings I've made with it so far it seems fine, both in mono (listening to its Mid channel only) and in stereo (recorded as M/S and converted to L/R in the recorder). Stereo listening so far has all been done using a single, fixed M/S ratio, since ratio is not adjustable on the F8 during M/S decode playback. Because of that the ratio is whatever equal input gains across all recording channels provided, since I have all eight F8 input gains linked so that while recording I can effect quick simultaneous gain adjustment across all channels with a single knob turn.
I've only used the direct M/S output mode of the microphone and have not tried it's two L/R output modes (narrow / wide stereo), but I don't really plan to use those.
3 shotguns across reminds me of early 90s Dead shows, many folks running that setup using modified Naks. I remember liking some outdoor recordings, but indoor venues not so much. I think it's b/c those shotguns had cruddy off-axis response and didn't do well with the reflected waves.
Yeah, that made me think back on the old Dead show section 3-mic setups using shotguns too. I've speculated in the past here at TS that the folks running an omni in the middle between two shotguns, as was somewhat common back then, may have gained some benefit of the omni masking much of the messy off-axis behavior of the shotguns, in addition to extending frequency response down to Phil bomb territory. But I've also said I believe it probably would have worked better to flip that arrangement inside out, with a single shotgun in the center flanked by sufficiently widely spaced omnis. Better bass, better ambiance, and probably better off axis masking too. Personally I wouldn't want to try using three shotguns on their own without the omnis and rear-facing mics to covering the off-axis. Spaced omnis with a stereo shotgun in the center and we're talking, but that's one more mic channel than the 3-mic Nak mixer supported.
Very happy that in this era no one needs to commit to mixing multiple channels ahead of a two channel recorder.
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I'm happy to report that I was able to try out a 3-mic* setup at a club show last weekend!
The show was Neighbor at Putnam Place in Saratoga Springs, a classic long-rectangle room. I intentionally set up at the very back by the board because I wanted to see how good of a tape I could pull from back there. I was also running solo and was a bit worried about the crowd.
My plan was to run 3 hypers: one in front (Peluso CEMC-6), two wide spaced (3 Zigma CHI FX SD-H), PAS. Because I was so far back in a narrow room, PAS angle was about 50°. The new 3 Point Improved PAS microphone configurations PDF suggests quite a wide spacing in this situation of ~164-170cm (65-67"). I only have (and feel comfortable running that high) a ~100cm bar. Due to this, I was only able to split the side hypers about 105cm. In hindsight, I could have run them on the ends to get a bit wider, but my omnis occupied those spots. (I didn't use the omnis in the mix.) Because the wide hypers were spaced a bit narrower, I shifted the front mic forward a bit. It probably ended up 30-40cm" in front of the bar. I ran my stand about 3m high (9.5'), dead center.
There was a lot of chatter around the mics, which made me a bit worried. However, upon listening I was really, really surprised how little it impacted the recording. My suspicion is that the wide spacing really dissipates the effect, as suggested in previous posts. The chatter is there, but it's much less distracting. Hypers obviously help with this too.
The only challenge was getting the wide hypers pointed properly at the stacks, as mentioned by goodcooker in the 2023 year in review thread. I thought I set them up fairly precisely, but there was still a noticeable level difference between the two sides. The addition of the center channel helped balance this out, however.
In the mix, I quite had a hard time taming the low end. I had to apply considerable EQ and compression to bring it to an acceptable level. Perhaps skipping shock mounts was a bit optimistic!
I'm very pleased with the outcome, especially considering the recording location and chattiness. To my ear, it definitely doesn't sound like a back-of-the-room recording. Thanks Gutbucket for all the info and guidance.
If anyone wants to play with the raw tracks, I'm happy to upload some. I had to leave at setbreak, so I only caught the first set, which you can listen to here:
https://soundcloud.com/al-w-5/sets/neighbor-2024-01-19-saratoga-springs-ny-set-1-full-set
* It's actually a 4 mic mix; I also ran a rear mic because I have the channels, but it's so low in the mix that it's barely noticeable.
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Thanks Al! I intended to give an extended listen last night but was unable to, so I squeezed in a brief listen this morning before work. Sounds very good given that far back of room recording location, with good vocal clarity and articulation, and decent management of the chatter back there. Very happy to find the arrangement working as intended. Much thanks for trying it out, posting about it and linking the recording here.
The new 3 Point Improved PAS microphone configurations PDF suggests quite a wide spacing in this situation of ~164-170cm (65-67"). I only have (and feel comfortable running that high) a ~100cm bar. Due to this, I was only able to split the side hypers about 105cm. In hindsight, I could have run them on the ends to get a bit wider, but my omnis occupied those spots. (I didn't use the omnis in the mix.) Because the wide hypers were spaced a bit narrower, I shifted the front mic forward a bit. It probably ended up 30-40cm" in front of the bar.
How far away would you estimate the recording position was from the stage/PA?
To gain some additional insight into the specific arrangement you ended up using, I modeled it in Image Assistant, using the maximum distance from the sound source that Image Assistant allows, which is 10m (~33') away. Other settings were: 3 supercardioids; L/R pair in PAS angled +/-25° (50° total) and spaced 105cm apart; center mic 35cm forward.
Here are the results:
Direct/reververant ratio stuff-
The powersum is pretty strongly forward-biased, which keeps the direct/reverberant ratio as high as possible and is a significant factor in what helps it work from a distant recording position. This due to the narrow inclusive microphone angle needed to achieve PAS in combination with the tight polar patterns. Specifically, the difference in sensitivity for sound arriving from directly in front verses 90° off to either side is ~8dB (unfortunately, Image Assistant only provides powersum info for the front 180°, I wish it provided a full 360° view). The powersum isn't strongly affected by changing the spacing between microphone positions.
Imaging-
The Total Stereo Recording Angle (SRA) is 112°. A 50° PAS angle is 45% of 112°. The stereo image of the band in your recording struck me as filling the stereo field pretty well (listening on headphones). I based all the 3-point PAS spacings on PAS angle = 75% SRA. That offset value is somewhat arbitrary but seems a good starting point. I can talk more about specific reasons for that choice if you like, and the most appropriate range of values for it is one of the main things I'd like to better determine with the help of folks like yourself trying these things out, so thanks again! 75% of 112° = 87° (er 84°, but that's value is what IA reports and is within 3°). ..so maybe we can get away with a lower offset value that equates to less spacing. ..or maybe it would be even better with some additional spacing and sound more upfront like at least in terms of image distribution. Over time we'll be able to better determine this, thanks to the help of folks like yourself.
^
[In comparison, based on a 75% offset the suggestion to use an L/R spacing of ~170cm (67") for a PAS angle of 50° produces an SRA of 67°]
The extra forward spacing probably didn't help. But didn't seem to cause any obvious problem to my ear either. Playing around with the 105cm / 50° arrangement in Image Assistant to optimize it as much as possible, it appears the best image alignment occurs with the center mic 23cm forward. In terms of imaging, shifting the center mic forward and backward changes the total SRA angle as well as affecting how closely the edges of the L/C and C/R stereo pair imaging sectors line-up and hand-off to each other across the center. Pushing it farther forward actually increases the SRA and messes up that center hand-over. This is good news as we don't need to extend the center mic position out much further than about 20cm to optimize things for most PAS angles.
More later.. gotta run..
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We record in that bar a lot and I'm going to say the soundboard half-wall where the mics were is about 60 feet from stage. Al, what do you think?
Additionally, there is a back room wall about ten feet behind where the mics were, which could have something to do with your bass taming need. (I do not know the bands material if it is bass heavy by design, etc)
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Thanks Kyle. Vocals through the PA sound quite upfront for 60' away in that relatively small room. Drums sound more distant, but may not have had a lot of reinforcement through the PA. I need to listen again, but don't recall obvious problems in the the bass - nice work wrangling that Al. I do wonder if shockmounts have much effect on that or not. I don't typically use them myself. I can easily hear handling noise through my rig with headphones when bumping it or moving it around at home, but don't hear any of that while recording music so I've decided to go without them for practical reasons (easier setup, much smaller and less visually apparent aloft, etc).
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Thanks for the review and info Gutbucket. Next time I'll keep the center mic closer!
Yeah, I'm not sure how far from the stage I was. The stage is 24' wide according to their website, so if the PAS angle was 50° then I was only 25' back, which seems too close. Maybe the actual PAS angle was closer to 40° or even 30° which would mean the stand was between 33' and 45' away, which feels like it aligns more with reality. (I remember feeling surprised how narrow the angle was.)
re drums: I have felt at the last few clubs shows I've been that drums are consistently not reinforced enough. It bums me out, let's get them in the PA!
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Yeah, without measuring it (usually via counting how many balled fists held at arms length it takes to cover the angle, each covering ~10°), the actual PAS angle is often less wide than I typically guess by just eyeballing it.
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Yeah, I measured by pointing the mics at the stacks and using a protractor app, and using the balled fist method, but perhaps I was still off ???
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Ooh, maybe I should get one of these… :lol:
Laser Measure with Camera, 328ft Laser Measurement Tool with Angle Finder, Indoor Outdoor Long Distance Laser Measuring Device with Electronic Horizontal Calibration, Tripod Included https://a.co/d/gL53DW5
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^ Hack it and do your own laser light shows!
Had to go look for a photo of Michael William's old school analog angle finder. The "Crocodile". Like hauling a piece of hardwood furniture around!
(https://www.williamsmmad.com/Measuring/Delux_Crocodile.jpg)
(https://www.williamsmmad.com/Measuring/DIY_Crocodile.jpg)
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New OMT4 rig
Last night was 6th of 8 Los Lobos shows in Hawai‘i and Seattle. I ran OMT4 with mk41s x/y PAS in the center and mk22s 4’ split, plus a stereo SBD feed.
I’ve assembled a new OMT4 rig, as V1 took me too long to setup/take down and is relatively heavy. It was built of 15mm al rods, 4 shock mounts, and lots of other hardware. V2 is built around a SRS 3D-printed nylon mount that does x/y and flies 2 - 2’ carbon fiber rods as split omni booms. Whole thing weighs 269g so can be mounted on one Rycote INV7-HG MKIII. The x/y portion can accommodate Movo windscreens when needed. It fits in my bag with the mk41s in place, so I just pop it on a stand, clamp on the 2’ rods, and put the mk22s on. So much easier/faster, and it's more than a pound lighter than V1. I've got the 22s on shock mounts for extra isolation, but may direct mount them to the booms.
Final addition to the rig will be wedges that angle the rods back at 18.25º so that the caps end up 7.5” behind the center pair. Scott’s working on them now.
Pictures of V2 below.
If folks are interested, I can post samples.
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Nice! Way more streamlined and compact. I totally relate to efforts to make setup and breakdown quick, repeatable, futz and error free, especially when they also make the flown array lighter and significantly less visually imposing. IME, these kind of improvements are what make using these arrangements practical to use on a regular basis, and not overly imposing and/or a PITA to run.
How wiggly is it with the outrigger arms in place and the entire thing supported by that single vertical duel-lyre suspension in the center? Using different suspension elements less capable than the Rycote Lyres to do something similar in suspending everything above the stand-connection point as one single unit, I found that achieving just the right springiness was a challenge. Needs to be floppy enough to effectively isolate the array from solid-born vibration transmitted through the support stand, yet at the same time, firm enough to not tilt or droop too easily. In playing around with that last year I was not able to get that to work satisfactorily, so have gone back to rigid mounting for now. A dual lyre using the appropriate durometer lyres is likely to work much better as it distributes the twisting moment over a significantly larger leverage area. Even if suspension hasn't really seemed necessary for my setup, I'm still scheming about ways of incorporating a less wiggly shock mount system that provides effective vibration isolation the next time I do a major rework of the setup.
If that Rycote shock mount in the center suspending the entire array is doing a sufficient job of isolating the X/Y supercard pair from vibration through the stand, it should also be sufficiently isolating the spaced pair. Plus, the use of more open patterns in the spaced pair position will naturally make them less susceptible to solid-borne noise transmission than the supercards in the center. I'd definitely try it with the spaced pair mounted directly to the rods as that will make it significantly more streamlined. Little adjustable-angle mic clips extending out from the ends of the tubes would be great, making it exceptionally visually clean by placing the mics in-line with the rods, and that would also maximize the spacing you can achieve. Extra credit if you are able run a small diameter mic cable through each tube!
I've been thinking about reworking my rig with carbon fiber tubes in place of the TV antennas for long time, but don't want to give up the super small diameter and telescoping extension feature. All the bits for making telescoping c/f rods I've seen use tubes of an overly large diameter, typically boom poles, and use large locking telescopic fittings which aren't necessary for this application. Just need them to telescope in/out with a hard-stop and a friction fit that makes them sufficiently rotationally stiff. Stunt-kite style c/f tubes are about the right diameter but telescoping end bits for them don't seem to be available. With the TV antennas, the ends of the thin steel tubes are simply swadged down at one end and flared at the other, and they have sufficient friction to avoid rotating. Would be really great to incorporate a very small diameter mic wire through the telescoping c/f tubes, but that wire would need to be spring-coiled to accommodate the telescoping. Fortunately all the mics I'm using on arms are currently two-wire.
How well do those little clamps secure the two highly cantilevered rods? Any sign of sagging or is the center mount stiff enough to avoid that, as well as being strong enough to avoid cracking at the base of the clamps? If that seems like it might be a potential problem, you might make a piece that inserts an inch or two into both two tubes, connecting them together to eliminate the bending stress.
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Whole thing weighs 269g
Very cool. Thanks for sharing.
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How wiggly is it with the outrigger arms in place and the entire thing supported by that single vertical duel-lyre suspension in the center? Using different suspension elements less capable than the Rycote Lyres to do something similar in suspending everything above the stand-connection point as one single unit, I found that achieving just the right springiness was a challenge. Needs to be floppy enough to effectively isolate the array from solid-born vibration transmitted through the support stand, yet at the same time, firm enough to not tilt or droop too easily. In playing around with that last year I was not able to get that to work satisfactorily, so have gone back to rigid mounting for now.
I'd definitely try it with the spaced pair mounted directly to the rods as that will make it significantly more streamlined. Little adjustable-angle mic clips extending out from the ends of the tubes would be great, making it exceptionally visually clean by placing the mics in-line with the rods, and that would also maximize the spacing you can achieve. Extra credit if you are able run a small diameter mic cable through each tube!
Getting the suspension right has been tough. I tried w Rycote single lyre mounts, Schoeps regular and heavy elastics, and the AKG shock mount, but none were right. It was a Goldilocks situation. I took a chance and ordered the dual lyre, and lucked out. It's a bit more see-saw than I'd like, but reducing the weight/leverage at the end of the booms has helped a lot. I've got some active cable clips from SRS and will bolt them directly onto the rod clamps, for a lighter and lower profile mount.
I've been thinking about reworking my rig with carbon fiber tubes in place of the TV antennas for long time, but don't want to give up the super small diameter and telescoping extension feature. All the bits for making telescoping c/f rods I've seen use tubes of an overly large diameter, typically boom poles, and use large locking telescopic fittings which aren't necessary for this application. Just need them to telescope in/out with a hard-stop and a friction fit that makes them sufficiently rotationally stiff. Stunt-kite style c/f tubes are about the right diameter but telescoping end bits for them don't seem to be available. Would be really great to incorporate a very small diameter mic wire through the telescoping c/f tubes, but that wire would need to be spring-coiled to accommodate the telescoping. Fortunately all the mics I'm using on arms are currently two-wire.
C/F has great benefits, but is harder to machine and make homebrew solutions for. Great idea on running the wire through the tube, I think my tubes are large enough to accommodate the binder plugs on my active cables, will try tonight.
How well do those little clamps secure the two highly cantilevered rods? Any sign of sagging or is the center mount stiff enough to avoid that, as well as being strong enough to avoid cracking at the base of the clamps? If that seems like it might be a potential problem, you might make a piece that inserts an inch or two into both two tubes, connecting them together to eliminate the bending stress.
The rod clamps are made to use with 15mm al rods for video camera setup, and are very robust. I tested them by putting a lot of force on the ends of the tubes, with no deflection noticable. When I add my angle wedges, the tubes won't be parallel any more, so I'd need to make a 3D printed piece to insert.
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Nice setup!
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Thanks. That further confirms my suspicion that the best solution for suspending the entire array as a single unit while avoiding excessive see-sawing is sufficient spacing between the suspension points, which the dual lyre arrangement helps to achieve. The suspension points can be spaced vertically or horizontally, either way it spreads out the rotational see-saw moment across a larger lever arm. The dual lyres can be used in either orientation, but are most compliant in the axial direction.
In my next build I'm thinking of trying a few spaced-apart low durometer Sorbathane pucks around the periphery of a horizontal plate that forms the center hub. Will take some prototype testing with headphones on.
It kind of looks like that center X/Y mount allows for adjustment of X/Y angle. Is that the case?
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Yes, the main part has slots in which curved pieces fit and rotate to set x/y.
There is also a 3rd slot down below for more vertical spacing of caps when using large windscreens.
See renders, attached.
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That's well thought out and very cool!
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Mr. Bucket,
Your comments got me thinking, and I've updated with a very low-profile and light mount for the omni caps.
It uses the neoprene expansion nuts that I didn't use for mounting the booms due to their deflection. In this application, the weight and leverage are so minimal that deflection isn't an issue.
See photos below.
Still have to design and print wedges to angle the booms back to get them behind the x/y pair, but almost complete!
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Nice set up Chris. Gets me thinking about if I should change up my rig...
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checht
That is some good looking modifications. kindms owns a camera rail set up with 15mm carbon fiber rods we occasionally use for split dpa omnis. he purchased the stock rotating mounts for them and attach the nbob active clips like yours to that. Your idea is very ingenious.
Thanks for showing us.
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Chris, you've inspired me to think more fully through the next revision of my OMT8 rig, which I've been planning on reworking for a while. See the attached PDF if interested.
The primary change will be the central support hub. The arms and overall geometry remain the same as before and I plan to stick with the black telescopic TV antennas for at least the outer portion of the L/R arms out to the omnis, but might switch to carbon fiber kite tubes for inner portion of those, or not. Also may use carbon tubes for the rear facing pair arms, since I don't actually telescope those in use. My most recent previous revision switched out the center forward-reaching telescopic TV antenna arm for a standard folding mic-clip, since like the rear-facing pair I no longer actually telescope it in use, and I plan to retain that standard folding clip so I can easily switch between the stereo shotgun I'm currently using in that position, the DPA/Naiant Mid/Side pair it replaced, or any other M/S pair I want to try.
The new single-piece central support structure will replace a stack of several aluminum arm supports I've used and reworked for over 15 years, supporting all five arm attachment points with the correct a pentagonal geometry, eliminating the need for little angle tweaks between arm pairs to get everything lined up right when deploying it on the stand, foot, or clamp or whatever. That should both simplify and streamline the arrangement, cleaning it up nicely.
The key component here is the pentagonal top plate (in orange in the PDF) to which all the arms attach. I'll probably build just that part first with a spigot stud on the bottom which mates to my various support options, the same as my current rig works.
But I've gone ahead and drawn it up with vibration isolation incorporated into it to reduce solid-borne noise transmission though the stand and cable. As mentioned, incorporation of suspension is really just something of a nice to have addition for me, but.. it will be nice to have, and this is an opportune time to consider it in the redesign. To do that the spigot stud gets moved from the top plate to a lower plate, which supports the top plate though 5 Sorbathane damping 'pucks' of sufficiently low durometer to be effective, positioned around the periphery of the top plate between arm attachment points so as to form a sufficiently wide support basis that hopefully keeps the top plate part and arms stable and not too wiggly. Bottom plate would be a spider or asterisk shape to allow the arms to fold down bewteen its notches for stowage / transport.
Also considering incorporating a multi-pin connector into the bottom plate, to which the cable bundle could be disconnected. Alternately, that will be a good place to incorporate Cat 5 /6 baluns which would eliminate the current cable bundle and further streamline things, but I'd still need two Cat 5 /6 cables to support all 8 channels.
I plan to fabricate this from aluminum plate, but also thinking it could be nicely 3d printed, using sufficiently tough materials such as whatever Scott at SRS uses.
PDF of the current concept is attached. The key illustrations are all on page 1. Page 2 is just an aesthetics comparison of a few different top plate shapes. I'm leaning toward the slightly starfish shaped version over the inflated pentagon.
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Very interesting and inspiring! A number of innovations in the new design which I'll be very interested to observe, the al plate and isolation system primary among them. Going to ethercon snakes makes sense, and I'd also take a look at what Redco has in 8 channel just to consider the convenience of 1 cable/connector.
Please keep us updated as you go along, pictures much appreciated.
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Will do, and thanks for the tip on checking out the Redco options.
Thinking further on wiring.. If the unicorn of a two-wire miniature fig-8 actually existed I could potentially fit everything through a single 9-conductor connection, in which case a single ethercon run using shielded Cat 5 / 6 (shield acting as shared ground) might work. Would super slick to be able to use a single Cat 5 / 6 run between the mic-array and the recording bag! Not sure about that though as it would require spiting up the individual wires of each twisted pair between two different microphone channels and I'm unsure if cross-talk might be too much. In a typical ethercon run supporting 4 balanced connections the twisted pairs are a benefit rather than a potential problem because each mic channel is assigned its own twisted pair, and any cross-talk between the two wires of the pair will be common-mode rejected by the balancing.
But to support any real-world-available fig-8 (balanced 3-pin XLR) requires one additional wire making for 10 conductor paths total, and supporting the stereo shotgun I'm currently using requires two additional wires (5-pin XLR at the mic, both Mid and Side balanced), requiring 11 conductors total with a shared ground.
If I didn't go ethercon, a single 9-pin D-Sub connector using the D-shell as the 10th contact for the shared ground would suffice in support of an unbalanced Mid through my current multi-conductor snake. In that case an off-the-shelf VGA monitor extension cable might work for the run from the mic array to the PFA/XLR-adapters at the recorder. And before incorporating the stereo shotgun into the array that uses a balanced Mid, that was my plan. But I probably won't go that route now because I want to support the balanced shotgun and accommodate alternate balanced center stereo-pair options.
Two ethercon connections could of course do it of course, as that could fully support 8 balanced mics.
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I'm leaning toward the slightly starfish shaped version over the inflated pentagon.
excellent design concept(s)
I like the starfish version. Seems more "flexible" for your storage style
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Yeah, functionally, I think they'd work pretty much same. I mostly think the starfish version just looks cooler and more purposefully designed! Going to go with that one.
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Haven't cut any metal yet but now have a few different windscreen options for the new center stereo shotgun.
Posted some photos of modding a Movo windscreen to make it the correct length in a separate thread this morning: https://taperssection.com/index.php?topic=204450.msg2408439#msg2408439
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This is probably the finest, to my ears, OMT4 recording we have done since using the DPA 4061's as our Omnis.
The venue is basically outdoors with a nicely shaped wooden roof.
ENJOY
(If anyone wants the raw samples I can provide)
N2: https://archive.org/details/phish2024-08-10akgck3dpa4061
MDAUD OMT4
microphones:
ch1/2: AKGck3 (hypercardioid) PAS > Grace Lunatec V2 >
ch3/4: DPA 4061 (omnidirectional) spread 8 feet apart>
recorder: Tascam DR-680|SD
processing: SD| Audacity|cdwaveditor|TLH|foobar2000 tagger
The rig pic shows the ck3s in the multi color ratties and we had the DPA's on windtech clamps on stands with an 8 foot spread this night
(Also more rig pics in the "see more" dropdown photo area)
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So cool!
8' seems like a lot, did you listen to just omnis much before mixing? Jim and Doug used to run a spread that big or larger outdoors at the Greek and Frost, with nothing in the middle, and we loved'd the sound, so I'm curious about how yours sounds...
Nice work!
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So cool!
8' seems like a lot, did you listen to just omnis much before mixing? Jim and Doug used to run a spread that big or larger outdoors at the Greek and Frost, with nothing in the middle, and we loved'd the sound, so I'm curious about how yours sounds...
Nice work!
I did. There did not seem to be too much hole in the middle, BUT, every time, the addition of the center channels seemed to make things "snap into place". There is a serious amount of warmth with the just omnis. I recall the OADE's would do those plexiglass plates and the spread omnis. I was patched out of them for GD Austin 1985 where they ran spread omni schoeps with a middle channel. "like butter" 8)
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I've been out of town and haven't had time to comment here yet but that Bethel Woods show sounds great Rock!
To my ear, nothing conveys the same depth, warmth, and a the same sense of "big, natural sounding there-ness" like a good wide omni spread. Totally agreed with the "snap into place" comment. The center pair really nails down a solid center anchor along with upfront midrange articulation and clarity.
I realize that I tend to think of and describe this stuff from a point of view that's the opposite of how most tapers tend to think about and approach it - for me the omnis are the primary foundation and the center pair improves things by reinforcing what is needed but to some degree already present in the omnis, just weak. Most tapers probably think of it the other way around, considering the center pair as the primary pair and the omnis a the "nice to have addition" which improves the center pair. Does that conceptual difference matter in any way? Probably not. Mostly just a philosophical difference I suppose, but I do wonder how that plays out in how folks approach taping. Looking at it from the opposite perspective, is the stuff the omnis provide that the center pair lacks on its own already there in the center pair but just weak? Some of it sure, but I do think one fundamental difference is that the spaced omnis provide good diffuse field decorrelation, or rather, achieve sufficiently low diffuse field correlation (..which is what non-taper acousticians and recording engineers associate with the contraction DFC. It doesn't read as Dead F****** Center to them) responsible for much of the perceived depth, warmth, and a the sense of "big, natural sounding there-ness" of the room ambience and audience portrayal. That isn't just weak in most near-spaced or coincident center pairs, its not really there at all.. maybe it is in a Blumlein pair, but that's more of a special case, and in a Blumlein pair the balance of that stuff verses the direct sound from the stage and PA isn't adjustable afterward in the same way that it is in a OMT4 arrangement.
So cool!
8' seems like a lot, did you listen to just omnis much before mixing? Jim and Doug used to run a spread that big or larger outdoors at the Greek and Frost, with nothing in the middle, and we loved'd the sound, so I'm curious about how yours sounds...
Nice work!
As I've probably speculated about too many times already in the OMT threads and elsewhere (apologies for repeating myself too much), outside of the microcosm of concert taping, recording a PA from a position in the audience presents a very strange acoustic scenario. I think a wide omni pair is capable of working alright on its own in that situation, without necessarily producing an egregious hole-in-the-middle as would be expected in a more typical recording situation, partly because of the unusual geometric relationship between two wide spaced PA arrays and the wide-spaced omni pair, combined with having a large degree of correlated mono content through the PA (the solid center stuff). The mono content from the separated PA stacks positioned on opposite sides of the stage reaches each omni on the same side in a phase coherent way, while the cross-path from the PA on the opposite is delayed by some milliseconds. While the non-mono decorrelated stuff through the PA (there is probably more of that than panned correlated content) is further decorrelated to both omnis. That's a very unusual acoustic situation that will only occur with a wide spaced PA and a relatively wide-spaced omni pair centered and oriented parallel to it.
I think that's why wide omni splits can work for tapers while they otherwise wouldn't elsewhere, even though it's almost always better with the addition of a center pair (or SBD).
If all this reads as Greek, just ignore it!
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Question for ya, Gut, on the recommended forward spacing of the center position mic(s) in say, an OMT4 config. Instead of rigging up the center position mic(s) in real time to be the recommended amount of inches forward of the spaced pair, can't this distance be created or dialed-in in post, by sliding tracks/channels forward, or backwards, in time in your audio editing software?
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Hmmm, only inches of forward placement? Considering sound moves ~1ft/msec, that's pretty insignificant
Yes, use your editing software to move your center mic forward in time
Same thing
:coolguy:
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Just got back after a month away without connectivity. Catching up..
Question for ya, Gut, on the recommended forward spacing of the center position mic(s) in say, an OMT4 config. Instead of rigging up the center position mic(s) in real time to be the recommended amount of inches forward of the spaced pair, can't this distance be created or dialed-in in post, by sliding tracks/channels forward, or backwards, in time in your audio editing software?
TLDR; Don't worry about center position forward spacing too much, it's far less important than achieving sufficient spacing along the L/R axis. Best to physically space things for reasons I'll go into below, but correcting with delay or sliding tracks along the timeline can often compensate well enough when physical spacing cant be achieved. Sometimes both in combination does the trick. If you can position the center microphone/pair forward a bit, do that. Don't worry too much about exactly how far. Anything up to about 9" or so should be fine.
If playing with delaying or shifting tracks in post, whatever sounds right is right.
Hmmm, only inches of forward placement? Considering sound moves ~1ft/msec, that's pretty insignificant
Yes, use your editing software to move your center mic forward in time
Same thing
:coolguy:
The difference between DIN, DINa, and NOS is also just a matter of just a few inches - significant or not? I think it best to think of center-forward spacing in a similar light.. its mostly about smooth imaging-linking / image-distribution. In the grand scheme of things that kind of stuff is a nice to have luxury. There are many other more important things to focus on first. But its real.
Whether time-shifting is the same and not.. and is significant or not, depends on how you look at it and what is being considered. In someway it is, in others it very much isn't.
How is it different?
Changing the physical spacing between two microphones affects time arrival in a specific way along the spacing axis. It makes for a positive time shift in one direction along that axis, a negative time-shift in the opposite direction, and no change in time-of-arrival for a plane wave arriving perpendicular to that axis. The directional vector is a critical aspect.
Applying delay or shifting one track along the time-line applies a positive or negative time shift for all direction of arrival. It's vectorless. It will do the exact opposite of a position shift for sound arriving from the opposite direction.
Manipulation of position and manipulation of time are inherently linked yet different in some important ways. Great when we can use one to compensate for the other, but can't always.
Some multichannel mic arrays require a combination of both to work optimally, but that's getting too complex for me.
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I call bullshit
Calibrating for a mic pair physically placed forward/backward in relationship to a spaced pair is exactly the same result as sliding the waveforms forward/backwards
If you recall, weeks ago the OP's question was "Instead of rigging up the center position mic(s) in real time to be the recommended amount of inches forward of the spaced pair, can't this distance be created or dialed-in in post, by sliding tracks/channels forward, or backwards, in time in your audio editing software?"
Yes, yes it can
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Chill out Kevin, No BS here except yours. Is it the same? No it isn't, demonstrably so and without question. Will it achieve what he wants? Most probably yes. Underpinning all this and as stated previously, its not the most important thing to be concerned about.
More fundamentally, in these OMT threads we discuss multichannel recording methods that are more complex than what is tends to be discussed elsewhere at TS. In support of that, we get into a more detailed analysis of what's going on in terms of acoustics. If you are content with simple yet incomplete and partially incorrect answers that's entirely your prerogative, but this isn't the thread for it.
If you honestly still think its exactly the same thing, I'm happy to walk you through why it's not. I described above how physically spacing two microphone positions is different than applying a time-shift to one of the channels relative to the other in the abstract, but an example may help illustrate the difference more clearly..
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Lets imagine this example-
Captnhook is recording an Americana band from a position is out in the center of the audience, and decides to try a 3 channel multi-microphone recording arrangement, lets say a small Decca tree consisting of three omnis arranged in a broad triangle. The good Capt'n was able to achieve the wide 48" left-right microphone-position spacing he wanted, but due to the limitations of his mic-bar he was unable to space the center microphone forward of the other two microphones by the 24" he was hoping to achieve, so instead, he has all three microphones are arranged along a line. "No problem", he thinks to himself, "I'll just delay the L/R pair to effectively shift them backwards in time with respect to the center mic channel, that will achieve the same thing as physically spacing them".
A rowdy audience excitedly files in. They know all the songs and have brought their own noise makers along to join in with the revelry. The accordion player takes the stage, nods at the good Capt'n and rips into the first number. Sure enough, almost immediately there is a young man furiously playing polyrhythms on a triangle off to the left of the recording position, a woman banging on a small tambourine to the right, and two guys tooting a penny whistles directly behind. Fortunately everyone is in tune and in the groove. What could have been a nightmare audience for a good recording turns into a beautiful and engaging live-performance experience. Everyone heads home smiling.
Capt'n gets home, transfers the files and gets to work.. To simulate the center microphone being positioned forward of the Left/Right by 24", he applies a delay of 2ms to the Left and Right mic channels, since it takes about 2ms for a wavefront to travel 24". He zooms in and looks at the waveforms to find the first crack of the snare. The wavefront from the drummer hitting the snare pings the center mic channel about 2 milliseconds prior to the Left and Right mic channels. Great, it works!
But what about the other sources of sound? The wavefront from the polyrhythmic triangle player off to the left would normally ping the left mic 2ms before the center mic, and 4ms before the right mic (First left, then center, then right, with 2ms between each arrival). But instead it pings both left and center channels simultaneously, and doesn't ping the right channel until 4ms later. Hmm. For the penny-whistle players its even worse. The sound from the penny-whistle players in back should arrive at the Left/Right channels 2ms before it arrives at the center channel out front, but instead it does the exact opposite- arriving at the center channel 2ms ahead of the Left/Right channels.. as if the two penny-whistle players and all the audience with them in back were actually standing out in front of the recording position, rather than behind it.
Most definitely not the same! Similar time-of-arrival distortions occur with any sound that arrives from any direction other than directly in front, including the PA speaker positions to the left and right of the stage.
How much this difference matters depends, and that's a different discussion. Sometimes it won't matter, sometimes it will, sometimes a lot.
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Lee you misunderstood the OP's question..
"Instead of rigging up the center position mic(s) in real time to be the recommended amount of inches forward of the spaced pair, can't this distance be created or dialed-in in post, by sliding tracks/channels forward, or backwards, in time in your audio editing software?"
Yes is the only answer, merely a shift forward/backward can be accomplished by sliding waveforms forward/backwards in software
Bullshit still in play here I see..
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The answer is still no. It can be simulated, but it's not the same. Whether that matters to you is up to you.
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"...young man furiously playing polyrhythms on a triangle off to the left..." :lol:
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Ok, insignificant then
Carry on, make great tapes
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The answer is still no. It can be simulated, but it's not the same. Whether that matters to you is up to you.
IMO- It is quite obvious that capnhook is trolling in this thread. I am aware there are a few on here who think that some people's knowledge is worth less than others. Apparently THOSE PEOPLE go by how many recordings one has posted or shared as part of their knowledge of physics and acoustics. Silly, bullying games - IMO.
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Grawk nails it, with admirable brevity.
It's not insignificant. It's a complex relationship, and a usefully comprehensive answer can't be reduced to a simple yes/no answer.. except for the fact that the two things aren't equivalent.. in most cases. Actually, there is one very-narrow, specific case where they are fully equivalent, which equates to recording a monophonic source, centered directly in front of the recording arrangement in an anechoic chamber. My assumption is Unclehoolio isn't doing that!
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Grawk nails it, with admirable brevity.
It's not insignificant. It's a complex relationship, and a usefully comprehensive answer can't be reduced to a simple yes/no answer.. except for the fact that the two things aren't equivalent.. in most cases. Actually, there is one very-narrow, specific case where they are fully equivalent, which equates to recording a monophonic source, centered directly in front of the recording arrangement in an anechoic chamber. My assumption is Unclehoolio isn't doing that!
This is how we tested loudspeakers for the Carrier Dome installation at SU during the construction of the Dome. We used the anechoic chamber usually used by the jet engine/turbine guys to measure them and decide which ones we preferred for the various arrays distributed through the building. B&K measurement mic 1 meter from the source into a B&K dual channel FFT analyzer (which compared the noise source to the speaker output).
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This is a forum for hobbyists. Lots of things matter, and people pick and choose based on their goals and desires. Every choice is a compromise of some sort.
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This is a forum for hobbyists. Lots of things matter, and people pick and choose based on their goals and desires. Every choice is a compromise of some sort.
correctumundo. My "compromise" here is that I chose to call out some BS rather than ignore it as I typically do. Boo hoo. >:D
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I didn’t get that you were criticizing mic placement when you said you tested loud speakers that way. I thought you were just dropping an interesting fact. What’s the argument that says that test applies to real world 3d microphone techniques?
Conflated a couple of posts and missed where you pointed out the obvious trolling. My bad.
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I take it as a cool factoid in that the special case described parallels standard anechoic testing methodology.
Also, I share an SU connection with rock in having attended SU after he was there. Carrier Dome had been in operation for a few years at that point. I never looked into the rumored to be well-paying student job of shoveling snow off the roof (I doubt that was actually a student job thing), but did get paid to usher concerts in the Dome and found I could make additional cash by sticking around to help pack up roadshow gear afterward. Fond memories of helping to pack the inflatable Floyd pig in it's case and disassemble the airplane.
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I have tried the technique of moving an XY pair a few inches ahead of a split omni pair
Not aware of which OMT configuration that one is
I heard no difference or improvement in the stereo image
Actually it sounds "smeared" to me when sources aren't time-aligned
I have heard no examples of Lee's for me to change my mind
I think most of this theory resides in peoples' heads, and not in reality
YMMV
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^
Same empirical experience as the cap'n. Moving the x/y center pair forward seemed to add phase smear, but could have been an artifact of my expectations.
Now I run OMT4 with the mics all in a line.
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I don't hear much difference, particularly when the wider pair are omnis.. but I do hear it somewhat when the pair on either side of the center position are directional mics forming something more akin to a near-spaced stereo triplet. I also hear it more when playing back using a center speaker, routing the center channel mic directly to that in an L/C/R speaker arrangement). Sometimes shifting the center forward just a bit seems to solidify and locks down the center of the stereo image a bit more, maybe because a wave front from directly ahead pings that mic a fraction of a second first, but that's speculation and could just be my imagination.
I'm sure I've written about this previously, but after wondering about and exploring center mic position a bit more last year, here's how I ended up with the current OMT suggestion of placing the center position around 15-20cm / ~6-8" forward in most situations. It's mostly a best compromise solution juggling a few different things, a way of doing minimal harm in the absence of complete data about which thing is most important, a suggestion that I've found won't cause more issues than it attempts to solve.
I see two primary variables that we are playing with here. One involves attempting to optimize for the coherent arrival of a planar wavefront pinging at all mics at the same instant. The other involves optimizing the smooth handoff of imaging sectors across adjacent microphones in the array. Ideally we want both. If either is sufficiently wrong we are more likely to get "smearing" of some sort or another.
The 15-20cm spacing suggestion is something of a compromise between achieving the most coherent arrival across multiple microphones for a wavefront arriving from directly ahead (best achieved with all mics in a horizontal line), verses wavefronts arriving from a slight angle, such as from each PA speaker. Can't have both at the same time. For a while I schemed about possibly spacing the center mic forward in such a way that a line between the center mic and left mic would be perpendicular to wavefront arrival from the left PA speaker. And a line between the center mic and right mic would be perpendicular to wavefront arrival from the right PA speaker. That angle is going to change with recording position, just like PAS angle does, but 15-20cm is reasonably close to achieving something like that in many cases.
Secondarily, OMT is strongly influenced by Michael William's arrays (Stereo Zoom and MMAD or Multi Microphone Array Design) and Gunter Thiele's OCT arrays. Those arrays are designed to achieving very precise image placement and smooth image hand-off between adjacent mic-pair sectors of in the array. OMT is not as seriously concerned with "distortion free" imaging. Clear, distinct, believable and engaging imaging is its goal. It's more specifically attuned to PA recording, and values achieving better impulse coherence for a wavefront arriving from directly ahead, in addition to and even more so than, sharp and clear if not totally accurate imaging. Still, sharp and clear imaging is a nice to have thing and one of the goals.
But with imaging concerns in mind, it quickly becomes apparent that arranging all mics in a line in unable to achieve accurate image linking between adjacent mic pairs along that line. Any pair of microphones regardless of the spacing between the two will have some Stereo Recording Angle that is greater than 0-degrees. Yes the wider apart they are the narrower that SRA becomes, but it is always "splayed out" at some angle wider than 0-degrees. So the imaging from adjacent linear segments is always going to overlap each other with some image smear. The only way to correct for that is to angle the segments somewhat relative to each other. Pushing the center mic forward a bit does that. The edges of the two adjacent segments that each have an SRA of some angle come closer to handing off from one to the other without overlap. If you play around with the Schoeps Image Assistant microphone-array visualizer, you will note that to achieve good image linking with any 3 mic array requires pushing the center mic forward.
So I compromised and made it a bit of a Goldilocks thing - seeking the middle way - not going fully one way or the other in the attempt to maximize collective benefit and minimize the potential for harm. 15-20cm seems to do that.
If you can't achieve that, or choose not to for whatever reason, no problem. Do your own thing. These are only guidelines that are deeply considered and have worked well for me. I hope they work well for others as well and very much enjoy our discussions about all this stuff here. Thanks for the bandwith.
Respect to all you folks, including those who feel this is just a bunch of hooha.
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Taking all this full circle, another reason for pushing the center mic forward a bit is that if afterward one decides they want to emulate having all the mics arranged in a line so as to get the tightest possible alignment for a coherent wave front arriving from directly in front, you can delay the center channel by a fraction of a ms to achieve that.
That may sound at first like I'm contradicting what I said earlier, but I'm not. Delay does not achieve the same thing as physical spacing. However, in this case we are flipping it around and going the opposite way. That allows the way in which the delay effects arrivals from other directions to work more in our favor rather than against us. Delay applied to a forward positioned center channel brings the wavefronts from the on-stage drummer and accordion player directly in front of the recording position into full alignment across all three mic channels.. and at the same time it further delays the sound of the penny-whistle players behind the recording position to the center mic channel, rather than shifting them forward in time in that channel and confusing things as it did in the previous example. It helps to keep the sounds arriving from behind perceptually in the back, and shift them out from the center toward the sides. The application of delay in this case works toward what we want to achieve rather than against it.
In other words, we can compensate for a forward positioned center microphone by applying delay to that channel in a way that works much better than attempting the opposite of trying to emulate a forward positioned mic position by delaying all the other channels of an array that had all mics arranged in a horizontal line.
In the more detail than you probably want category, here are two examples of arrays that require the combination of positioning AND delay in combination to achieve the desired result-
Gunter Thiele's OCT arrangement later incorporated a special optional modification intended to best optimize it for two channel stereo playback rather than of L/C/R speaker playback. It's called OCT2 and the change is that it pushes the center microphone position much farther forward than the 8cm / 3" standard center forward positioning of OCT, and then requires the application of delay to the center channel to bring it back into alignment again (with regard to a wavefront arriving directly from the front). That change achieves improved diffuse field decorrelation that makes for a better, more open and diffuse-sounding impression of the room impression and reverberant decay, and reportedly improves phantom center stereo imaging a bit.
Similarly Michael Williams special 8-channel Magic arrays use an even farther forward positioned center channels (something like 2 meters or so foreword I think) along with a required application of delay to that channel to bring the imaging sectors into alignment. Interestingly, that extreme forward spacing of the center mic position allows the flanking near-spaced mic pair to remain essentially unchanged from what would be optimal for 2-channel recording. That pair no longer needs to be spaced something like twice as wide horizontally as it otherwise would when incorporating the center channel mic. Ironically this would imply it would be the best option for tapers who wish to try adding a center mic to their preferred near-spaced two-channel stereo configuration, since the two channel config remains the same as before, however the center mic position needs to be positioned WAY foreword and delayed. And unfortunately that's totally impractical for tapers. It's far more challenging to space one mic position forward by something like 2 meters than it is to space a line of mics out horizontally buy a couple meters, either with or without a little forward spacing of the center mic position.
Part of the game is juggling compromises to find a comfortable limit of what can be practically achieved, and we all have to draw the line somewhere. The ongoing evolution of OMT reflects the pursuit of optimal solutions within the framework of what has been practically possible for me, along with some projection of where it might be able to go further. Take from it whatever is useful for you.
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Thanks for the bandwidth, also
I'm a tech guy used to fixing engineering mistakes, and I look for practical solutions
Still waiting to hear some of Lee's magic
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Thanks for the bandwidth, also
I'm a tech guy used to fixing engineering mistakes, and I look for practical solutions
Still waiting to hear some of Lee's magic
I am a tech guy with a degree in acoustics who has earned US Patents on audio signal processors.
I do not need to hear anything from Lee to know these theories have merit.
In fact, since I own microphones and record live shows all the time I test out these things for myself.
I know what FFT analysis is and can reasonably deduce the multi channels of signals with my ears and then use analysis tools. Therefore I am certain of both the benefits and limitations of these applications.
It truly isn't rocket science although there is math involved. bandwidth used >:D
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It is quite frequent that I presume I might use delay to fix a thing, and it sorta does, but I come away with evidence that a better mic placement would have in fact been the only truly satisfactory way, given all the multi-path information.
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Hey all, back to reading TS.com after a long time away and catching up on this thread. Really interesting chain. Does anyone have any samples of running subcards / widecards on the outside in place of omnis. I don't have omnis but have a pair of DPA2015s coming my way. Will be dipping my toes into the OMT waters when they arrive. I'm assuming these are a suitable substitute after reading the PMT progression document. Love the experimentation happening here
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^Welcome back! Others have run subcards in place of the omnis. I've long been meaning to but don't have a pair of them to do so myself. Was going to pickup a pair of LineAudio CM3 in the yard just last week to do my own tests but missed 'em. That said, they fit into and nicely satisfy the theories. I have used OMT4 setups that have a M/S pair in the center between medium spaced cardioids or supercards as mentioned below a number of times with good results.
Here's a link to a post in the previous OMT thread with most recent updated OMT PDF's to date- https://taperssection.com/index.php?topic=191953.msg2311360#msg2311360 (https://taperssection.com/index.php?topic=191953.msg2311360#msg2311360)
Also quoted here:
Updated OMT PDFs attached. Still need to roll these into a revised complete booklet along with a few additional sections I'm still working on. These currently supercede the booklet linked in my signature.
* OMT overview (rev 4)_introduction.pdf (https://taperssection.com/index.php?action=dlattach;topic=191953.0;attach=146767)(77.88 kB)
* OMT overview (rev 4)_standard arrays.pdf (https://taperssection.com/index.php?action=dlattach;topic=191953.0;attach=146768) (100.2 kB)
* OMT overview (rev 4)_OMT progression.pdf (https://taperssection.com/index.php?action=dlattach;topic=191953.0;attach=146769) (96.79 kB)
* OMT overview (rev4)_OMT3.pdf (https://taperssection.com/index.php?action=dlattach;topic=191953.0;attach=146770) (81.67 kB)
* OMT overview (rev4)_OMT4.pdf (https://taperssection.com/index.php?action=dlattach;topic=191953.0;attach=146771) (122 kB)
* OMT overview (rev4)_OMT5.pdf (https://taperssection.com/index.php?action=dlattach;topic=191953.0;attach=146772) (90.47 kB)
* OMT overview (rev4)_OMT6.pdf (https://taperssection.com/index.php?action=dlattach;topic=191953.0;attach=146773) (116.79 kB)
* OMT overview (rev4)_OMT7.pdf (https://taperssection.com/index.php?action=dlattach;topic=191953.0;attach=146774) (83.99 k)
* OMT overview (rev4)_OMT8.pdf (https://taperssection.com/index.php?action=dlattach;topic=191953.0;attach=146775) (80.51 kB)
* OMT overview (rev4)_OMT6-8 with MS omnis.pdf (https://taperssection.com/index.php?action=dlattach;topic=191953.0;attach=146776) (126.67 kB.)
And now here we are in 2025 and I've still not gotten around to updating the original OMT booklet linked in my signature with the above revisions. Really need to make time to do that. Last year I instead worked on updating the Improved PAS thread to include an illustrated PDF that extends it to cover not just 2-channel PAS, but also 3-mic position PAS arrangements using 3 or 4 microphones total, placing a coincident pair or just a single mic in the center. I decided to focus on that in my free time instead since I considered it more helpful to most tapers and more likely to get applied than this more esoteric multichannel OMT stuff. Extending PAS to 3 or 4 channels also begins to converge it into OMT. It's now become a special subset of OMT2, 3 and 4 configurations specific to PAS.
Here's that latest Improved PAS PDF- PAS, 2 & 3-microphone (Rev2).pdf (211.72 kB) (https://taperssection.com/index.php?action=dlattach;topic=167549.0;attach=151178)
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Hey all, back to reading TS.com after a long time away and catching up on this thread. Really interesting chain. Does anyone have any samples of running subcards / widecards on the outside in place of omnis. I don't have omnis but have a pair of DPA2015s coming my way. Will be dipping my toes into the OMT waters when they arrive. I'm assuming these are a suitable substitute after reading the PMT progression document. Love the experimentation happening here
Following Gut's advice, I have put together a config with mk22s on the outside and mk41s x/y in the center. My faceorite outdoor rig ever.
https://archive.org/details/LosLobos2024-05-27/LL20240527.omt4.2448-01.flac
Encourage you to see if a similar config works for you.
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I don't get it. When you say x/y PAS (41's), from your description, you are recording from inside the gazebo behind the band? A couple things there don't make sense to me.
Also, got a picture of your bar?
I'd love to see the setup if you grabbed a picture. I like the idea.
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Gazebo is in the back of the house, not back stage.
Make more sense?
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Gazebo is in the back of the house, not back stage.
Make more sense?
Very much so. I was looking at your picture of the stage.
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Thanks gut and checht for the responses. My 2015s arrived so I’ll be looking to test it out in the near future, will report back here with results. The primary place I tape, Ardmore Music Hall, probably wont let me spread them too far so I'm going to work with a 2' spread to start and see how it goes. We. tape LOC directly in front of the left stack about 30-40 feet back. Going too far would basically put the left side right over the bar area which gets pretty chatty as it is. I can increase it by running a boom going right about 5-6 feet, which I'm debating but that would put the mics over a seated crowd area for VIP tickets - not sure how the venue would feel about that - unless I were to consider going up much higher than I normally do go get out of their way a bit. Either way, will come back with my results
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Glad to spread the gospel.
One think I appreciate about omt4 is the incredible versatility. Starting with choices around outside spread and inside config then moving to post-processing options, one can really create a wide range of final product.
Lately I've been taking the mk41 track and pulling out the vocal stem then adding that back into the mix to reinforce the vocal and increase presence.
Fun to play with all the variables, and sometimes the original sounds best too. Ratio of center to outside mics is huge.
Have fun!
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Thanks gut and checht for the responses. My 2015s arrived so I’ll be looking to test it out in the near future, will report back here with results. The primary place I tape, Ardmore Music Hall, probably wont let me spread them too far so I'm going to work with a 2' spread to start and see how it goes. We. tape LOC directly in front of the left stack about 30-40 feet back. Going too far would basically put the left side right over the bar area which gets pretty chatty as it is. I can increase it by running a boom going right about 5-6 feet, which I'm debating but that would put the mics over a seated crowd area for VIP tickets - not sure how the venue would feel about that - unless I were to consider going up much higher than I normally do go get out of their way a bit. Either way, will come back with my results
This is one of those situations where tapers run into hurdles. If running a wide split is just going to piss off the venue and other patrons and introduce a bunch of chatter into your recordings you hit diminishing returns for your efforts. I only run wide splits outside where I can do it without intrusion on others and reap some of the benefits. A lot of my inside taping opportunities are marred by chatty patrons, drunks and reflective surfaces of poorly executed sound systems/venues so I don't get to experiment as much as I'd like.
During the last decade the ability to run lots of channels in the field has gotten much easier so it's opened up the ability to experiment. If you find that the additional channels aren't adding what you are looking for when you are mixing it you have options - and options are great. I've often done things like described in this thread like low passing open pattern mics and only mixing that into my main pair of more directional mics. Having those options to draw from later is pretty awesome.
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Good points. I find it really helpful to set things up in such a way that I can easily adapt my setup to the situation- running the outside pair wide whenever and wherever possible, while compromising to something more compact when necessary allows me to make the best of each situation while avoiding pissing anyone off.
I will say that when possible, I find a wide spacing particularly beneficial in regards to how the audience reaction is portrayed, and that applies to both good and bad audience reaction - enthusiastic engagement and distracted chatter. Recording from the same position and using the same polar patterns, the audience reaction remains at about the same level in the resulting recording either way, but sufficient spacing decorrelates much of the off-axis content that arrives to one microphone a fraction of a second before the other, serving to differentiate that content and pull it away from the more highly correlated content arriving from the stage and PA more or less simultaneously across all channels. It helps make specific audience conversation streams easier to ignore via the psychoacoustics associated with the "cocktail party effect".
Switching from omnis to subcardioids or a tighter pattern is one way to make the best of a narrower spacing without as much compromise but ideally requires angling that pair more widely to compensate- essentially trading spacing against level difference derived from the combination of pattern and angle. But that can be a tough trade-off in a less than acoustically ideal indoor situation where keeping the spaced pair pointed more toward the stage and PA is advantageous, since a more narrow angle between mics ideally requires more spacing not less. It's a situation of opposing constraints. And that relationship is the basis upon which Improved PAS was extended to three mic-positions last year.
This OMT stuff is all about exploring ways of making the best of the situation. In reality, a lot of the time the practicalities of what we are able to do are going to overshadow what we might prefer.
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New thread so I'll add some of my latest thinking-
Sometimes I flip the script a bit regarding the position(s) in the mic-array in which which I want the most forward directionality - that is to say, the microphone positions in the array that are intended to pick up the least room and audience. This is basically what the OMT4 "tough room variant" is intended to do, mentioned on page 2 of this PDF- OMT overview (rev4)_OMT4.pdf (https://taperssection.com/index.php?action=dlattach;topic=191953.0;attach=146771) (122 kB), in which a more-directional narrower-spaced pair is substituted for the wide spaced omnis and angled toward the PA. What isn't mentioned in the current "tough room variant" PDF write up is that when doing that I'll sometimes shift to using a wider Mid microphone pattern in the center Mid/Side pair. Because if the near-spaced directional pair in PAS is providing most of the upfrontness and vocal clarity, I can use a more open Mid pattern to sort of flesh out a bit more room and depth dimension from the center Mid/Side pair.
In a way, that's the opposite of what has been my standard OMT thinking about having the center pair primarily focused on providing the direct sound to the greatest extent possible with minimal room and audience content.. which encouraged me to switch to using a shotgun Mid a year ago - a practical improvement I like for the most part. Recently that has me thinking about the potential of a further optimization to the OMT8 setup I'm using (also applies to OMT 5 or 6 without rear facing mics) that uses the combination of a wide spaced pair of omnis, a pair of near-spaced directional mics and a coincident center pair. I'm thinking I might ideally use the current arrangement with the shotgun Mid and near-spaced superard pair angled +/-45 degrees when recording from a relatively close sweet spot audience position or on-stage (pointing the shotgun Mid at the snare drum), but when far away switch out the near-spaced +/- directional pair for PAS shotguns and switch the center Mid to a wider pattern. This comes from how I use the channels in a 2ch L/R mix. When farther back, the ~2' near-spaced supercard pair angled around +/-45 degrees often provides much of the clarity up front proximity and zoom-in-ness. Switching those to PAS shotguns might optimize those qualities further when recording from a position farther back, while the more open mid helps make up for the more ambient stuff that the less open and more tightly angled near-spaced shotgun pair is longer proving to the same extent. Alternately when recording from the sweet spot or on-stage, the roll is reversed with more isolated direct clarity from the Mid and more openness and stage imaging from the near-spaced pair.
This comes from the practicalities of what each pair is providing in the stereo mix. In a no holds barred type situation where I can "put whatever setup wherever I like", I still think it best to keep the room out of the center pair (keeping it SBD like) as much as possible and to likewise limit pickup of direct SBD-like content in the mics focused more on translating the audience and room sound.. which I suspect remains the right thing to do for surround playback regardless of the situation. But in a stereo mix where the various mic channels of the array are no longer dedicated to specific playback speakers and are instead being mixed together in such a way as to provide a more convincing illusion, we are freed to use the channels in somewhat different rolls.
So that's yet another potential acquiescence to practicality. I may never actually get around to trying it. But I would love to try a pair of DPA 4017s in place of the near-spaced 4098s, and if that pans out, have the option of switching one of those over to the center Mid position when called for.
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My previous two posts above both use too many words to essentially make these points-
- In a distant, noisy room, point 'em at the PA, and if you can, space them more widely apart to compensate for the narrower angle between the pair. Improved PAS technique provides specific answers to "how wide?"
Dealing with audience noise is made easier by configurations that use wide spacings for a few reasons:
- A wide spaced mic setup does not increase the pickup of audience noise any more than a narrow-spaced or coincident mic configuration.
- A wide spacing doesn't by itself reduce audience noise, but will make it less annoying and attention grabbing in the resulting recording. Particularly audience noise which occurs near the recording location.
- Without moving to a different recording position or increasing mic height, the only way to reduce pickup of off-axis audience noise as much as possible is to point a pair of directional mics directly at the PA/stage (PAS).
- A pair of directional mics arranged in such a PAS configuration is going to have less angle between mics than typical stereo microphone setups. The smaller angle reduces pickup off-axis, including audience noise, while maximizing clarity and pickup of the PA/stage sound by keeping those sources on-axis.
- The sound from a stereo pair of directional mics with a narrow angle between them is going to be greatly improved by using a wider spacing in order to achieve good stereo qualities.
In general, wider mic spacings are good in multi-mic stereo arrangements whenever possible, although there are plenty of situations in which a wide spacing isn't practical. But if and when you can do it, wide helps when positioned farther back, when the room acoustics are not so good, and when the audience is noisy. Wider is also good when the situation is great and more open polar patterns can be used. Narrow is also good in a multi-microphone array since it serves as a good counterpoint center anchor balancing the Wide.
When using more than two mics, wide is good, but can be challenging to achieve. Switching to more directional mics can somewhat reduce the need for going quite as wide. Go for good without stressing yourself out or pissing other people off.
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Gaffer tape-
Found myself on something of an archeological dig last weekend reworking the multichannel rig before recording Sat night. Rig was in bad need of rework and I still plan to totally reworking it prior to Amp Jam #1 on the Suwannee in early March, but just needed to get it all back together in straight presentable shape quickly for use that night. Found myself digging through layers of old gaff tape, some from more recent quick ad-hoc repairs (chopstick or two as repair splints on kinked telescopic TV antenna mic-bars), and some deeper layers foundational to the core structure and wire-routing. That made for a few interesting observations on extended long-term gaff tape use.
The more recent repairs and mods were made using the cheapo Amazon gaff tape, ranging from a couple months to a couple years old. It's 2", fabric backed, black adhesive. Seems to work about the same as classic gaffer tape when fresh. Rips and conforms nicely. I actually prefer its black adhesive over white as long as its fresh. Good medium adhesive tack, the tape is thinner, doesn't show any white edge, and pulls away cleaner without residue from some surfaces.. when fresh. After aging it retains its stickiness and never seems to dry out which is good, but grows increasingly "slimy sticky" making it sort of slide around under load, and it's residue becomes difficult to get off hands and whatever else it touches. Pulled off layers of old tape strips are super tacky gooey on both sides. Ugh, a real mess to disassemble!
The older tape underneath more foundational to some of the rig structure and wire-routing is maybe around 5 to 7 years old.. dunno might be 10. Its classic well known good stuff, ProGaff or ShureTape not sure which. 2" fabric backed, white adhesive. It aged as expected, remaining fully attached, but with the adhesive drying out completely. Pulling it off, the removed tape was completely tack-free on both sides, produced a little cloud of white dust and left behind a hard white textured residue on the surface which wiped off easy enough with acetone.
Thing was I needed to reassemble this thing and had no roll of fresh tape at hand. Couldn't reuse the older "better tape" strips with no adhesive remaining. Salvaged the best of the A'zon tape stripa that were the least slimy and least sticky on the front side and made do. Yuck. Nasty. Gotta do what you gotta do. Got it done. Worked out fine.
I've been meaning to rework this rig since my posts about doing so here a year ago which included a few drawings of a new support structure. All the while last Saturday I was scheming on the redo with a reemphasized goal of the elimination of as much gaff tape if possible, at least in its "as new" state. Anything goes to affect needed repairs in the field as always. Gaff tape is great stuff and will always be in the bag, but..
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Temporary revision eliminating tape-
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Found these from 2019 using the Shure windscreens, prior to the various repairs and implementation of the Movo windscreens. A couple of the Movos required gaff taping connection to the arms until now. This reflects how the rig was with the foundational tape only, mostly used just to route wires.
Recording NC stream burbles
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Last Sunday night. Directly behind the board, which was positioned relatively close that night. Worked out well. Promoters came by to give the thumbs up. Sound guy and bands happy. Audience sees this rig there regularly with no complaints. Couldn't do this kind of thing everywhere, but works it out nicely here.
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Gut, do you have any of your recordings posted anywhere to grab a listen?
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Sorry, other than a few things posted here over the years, I don't. I'm rarely able to make the time to properly mix these down to 2-ch stereo, but I've long planned on working toward doing that for the ones I am able to share.. for everyone but especially for you folks following these threads. Life pulls hard in many directions. Will see if I can work toward getting there in 2025.
Until then if you ever find yourself in South Florida hit me up. We can don headphones and I'll play a few things directly off the 8 channel recorder. Actually most enlightening to do it that way, as you can clearly hear what happens upon muting/unmuting the various channels and how they collectively work together. I need to figure out a way of doing that for specific examples in these threads. A video that visually shows the switching between which channels are active is probably the best route for doing that, other than simply doing it in person.
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Interesting examples of the application of "Blumlein shuffling" have been posted by Voltronic over in the Acoustic Recording Thread (https://taperssection.com/index.php?topic=203942.msg2423527#msg2423527), followed by my analysis and some discussion of what's going on with it. To avoid the oversaturation of that thread with a discussion of how shuffling might be applicable to multi-mic arrays such as OMT setups, I'm continuing that discussion here.
Here's where I left off over there-
Thanks for starting the conversation on shuffling with your examples. Super interesting stuff. Hope I haven't gone too deep into this for the others following.
A few of my conclusions-
- I'm now convinced that a not overly wide spacing in combination with shuffling is an optimal arrangement for a stereo pair of omnis when used on their own.. in most cases - there are always exceptions and I think those tend to arise in taper situations more so than typical recording scenarios. The oddity of superwide 20-30 foot omnis splits sometimes working great for PA amplified stuff without suffering a "hole in the middle" is an example of that.
- This is great news for tapers! Less wide spacings are far, far, far more practical, achievable, and less-imposing.
- Application of shuffling may make for an improvement of any taper recordings made with a coincident or near-spaced pair. That's most of them.
- Thinking about how it might apply or not to multi-microphone arrays, meaning those which include a microphone, pair, or more mics placed in the center between a wider spaced pair.
Forgive one additional indulgence in thought experiment about that before I let this go.. actually, strike that. Probably best if I take that over to the OMT thread.
My first thought is that in a multichannel mic array which is to be summed to stereo (specifically 3-position PAS and OMT) we'll still need to get the microphones of the channels that are going to be summed far enough apart to mix without conflict. The mics feeding the channels to be summed either need to be close enough together or far enough apart* to avoid potential problems that can arise when positioned somewhere between - the sort of all-or-nothing, inverse Goldilocks problem of mono-compatibly. Shuffling may not be of help with that. We can experiment to find out of course. And fertile ground for trying that is remixing multichannel OMT recordings in which less than the desired amount of spacing was used for whatever reason.
Second is how and where shuffling might be applied. To keep it simple, let's assume a 3-channel arrangement which consists of two omnis with a cardioid in the middle. The addition of the cardioid in the middle, along with providing other benefits, fixes many of the things that are problematic with a wider omni spacing, but it's introduction also requires that the spacing be made wider. Alternately it might be a 3-mic triplet of angled directional mics that are able to use somewhat less spacing. Either way, in this thought experiment I'm using a narrower spacing than I'd would otherwise prefer, and attempting to compensate with the application of shuffling.
I see three potential ways of applying shuffling to the raw 3 channel L/C/R output from the array when mixing that down to 2-ch L/R stereo:
1) Shuffling is applied to just the L/R outside mic pair prior to mixing. ..Or to to the L/R mixed stereo output. Either way the result should be the same as the contribution of the single center mic is made identically to both L/R channels, effecting only the Sum not the Difference. This is the essentially the same as adding shuffling to any existing recording.
2) Shuffling is applied to L/C, and C/R, but not to L/R.
3) Shuffling is applied to L/C, C/R, and to L/R.
#2 and #3 are the interesting ones unique to a three channel array. Fun to think about what's going on with those.
Might it address the potential for imaging conflicts in a 3-channel, 3-position array from having three different SRAs in play in such an arrangement? One for the L/C pair, another for the C/R pair and a third for the L/R pair. As posted about here an in a few other threads a few months back, we can arrange for the L/C and C/R imaging segments to "hand-off smoothly to the other" by way of "steering" their SRAs via forward spacing of the center mic. If all the mics were placed along a single line those two SRA's would overlap each other in the center rather than the inner edge of the two SRAs lining up to affect a smooth hand off from one to the other across the center. The problem is there's also an SRA associated with the L/R mic pair, and that SRA is considerably narrower than the combined SRA of L/C + C/R.
The question is, does shuffling alter SRA? If only at low frequencies where the shuffling filtering is active? Can we use that to our advantage in this situation? Can we get the combined SRA L/C + C/R closer to the SRA of L/R with a clever application of shuffling?
I'll have to think about this some more.
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I finally got a chance to run the new OMT4 setup. This is moe. from Friday and Saturday nights at Brooklyn Bowl Philly. I ran DPA2015 wide card about 2 feet spread, with 4018VL hypers XY in the center about 4 inches in front. I'm going to experiment with pushing the hypers forward more, in addition to swapping out the XY with just a single forward facing 4011 as a center channel. More to come. I think the results are really nice I'm definitely a believer. There's a punch but an openness to it as well. Really interesting to play around with
https://drive.google.com/drive/folders/1ZIlpRH27teHgOSKM388h2ms94F45zJ0-?usp=sharing
https://drive.google.com/drive/folders/1uvQJaRMAKMIYa8qIFm2zFdhxQtJPS1Iy?usp=drive_link
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Right on. Glad you're liking what you hear. I'm on my way out of town for a week but will give a listen next week upon my return. Your description sounds like what I like and listen for in these setups- punch and clarity along with openness and depth.
Yeah, will be good to compare against a single center mic.. And as an extension of that, if you have a fig-8 consider Mid/Side in the center, since that way you can go from single center mic to coincident stereo center by simply adding as much or little Side channel as you prefer afterward. That makes for a very cool post tweak. Without a fig-8.. if you find you prefer the X/Y in the center over a single center channel, try playing around with X/Y angle. 90-degrees is a safe start, but narrower (so as to get that pair closer to PAS) in combination with a stereo width tweak afterward to taste, is similar to a Mid/Side mic setup.
[edit]- If up for it, try adjusting the stereo width of the center X/Y pair afterward regardless of what X/Y angle you use. You can try that with the recordings you've already made. It's sort of the "secret sauce" for me when mixing these arrays down to stereo. Sometimes the amount of width used for the center pair when mixed with the wider-spaced pair ends up being about the same as I'd use for a center coincident-stereo pair on its own, and other times I use less. However, I almost always prefer at least a little touch of width/side-channel there. Very fun to hear what it's addition does in the mix.
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Got to try a little OMT tonight on a trio with an xy pair in the center and some wide cards spread at about 10", lip of stage (sorta, it was on the ground) about 1.5' from the musicians. Need to listen to it, but it was a fun experimental little compact setup.
Now this is some bad ass shit here: https://www.youtube.com/watch?v=VxC1xiIkxd4
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Here's God Street Wine from last night, running LCR. 2015s out about 2 feet and 45 degrees, and a 4011 as the center channel about 8 inches in front of the 2015s. Ended up putting in a bit more of the 2015s than the 4011. Sounds good
https://drive.google.com/drive/folders/1sSGLcXNdCMH7n3dkIzMMKXISJEprol5q?usp=drive_link
folders for the raw files and the matrixed show for reference
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Here's God Street Wine from last night, running LCR. 2015s out about 2 feet and 45 degrees, and a 4011 as the center channel about 8 inches in front of the 2015s. Ended up putting in a bit more of the 2015s than the 4011. Sounds good
https://drive.google.com/drive/folders/1sSGLcXNdCMH7n3dkIzMMKXISJEprol5q?usp=drive_link
folders for the raw files and the matrixed show for reference
Listened to a couple of the processed tracks, and a center mic 8 inches ahead still sounds good to me. Just like you mention, there's a lot of good stereo openness, but also a punch / clarity mixed in from the hyper. Kind of a best-of-both-worlds. I wonder how far that center mic has to go before it starts to sound off or phasey....
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Ive not encountered any obvious phase issues with the two times Ive run like this. Both times I had the center mics forward anywhere from 4-8 inches. From everything I've read and what Gut has developed / documented. that seems to be the best approach - though others have noticed a smear when all four mics are not on the same plane. After listening to GSW and the LCR approach, I do think I'll go back to running the center as an XY pair a bit more, the single center channel here seems to be missing something that would be additive in a good way
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Ive not encountered any obvious phase issues with the two times Ive run like this. Both times I had the center mics forward anywhere from 4-8 inches. From everything I've read and what Gut has developed / documented. that seems to be the best approach - though others have noticed a smear when all four mics are not on the same plane. After listening to GSW and the LCR approach, I do think I'll go back to running the center as an XY pair a bit more, the single center channel here seems to be missing something that would be additive in a good way
I've quite often used a center cardioid or hyper and placed it 4in or so in front of the usually subcardioid main pair after reading about it in several places. In a couple of problematic muddy sounding venues it does a lot to give a forward facing sound that helps combat too much room and cuts through the mids and highs a little. I've tried various tricks at the mix with various results but using a high pass at 500hz on the center has worked out great a few times. Seems counter intuitive but it worked to snap the center "into place" so to speak.
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I'm back in town as of this morning and will give a listen to the links you guys posted when I can.
Although I now aim for placing the center mic position around 20cm / 8" forward, I've had the coincident center-pair as far as about 15-20" forward of the L/R spaced pair or so without a problem, recording from both on stage and when positioned just front of the board about 30-40 feet back. That was using one of these folding feet as a triangular mic-bar:
(https://www.bhphotovideo.com/cdn-cgi/image/fit=scale-down,width=500,quality=95/https://www.bhphotovideo.com/images/images500x500/impact_ls_3sb_backlight_stand_base_1625672839_1119713.jpg)
That folding foot comes provided with one drilled and tapped hole at the end of one leg, so I drilled and tapped the other two as well to use it as a triangular mic-bar, and the 18"-20" spacing equates to the diameter of it's footprint. On stage I use it right-side-up, more or less an equilateral triangle about 20" each side with or without anything attached to the center stand part of the foot. Back by the board I flip it upside down and put it atop a telescopic bar which is secured to a railing with a Superclamp. Then the L/R pair legs get pushed straight out to either side in-line with each other, making the triangle a bit wider and shallower. Guessing 24" wide by 15" deep or so. No problem, and in the past have gone even further..
Way back when I was using four spaced omnis in a diamond array - think small Decca-tree which also included a rear omni - I had the center omni positioned anywhere from around 12" to 36" forward of L/R omnis, with all of them sphere mounted. Never noticed a smearing problem with that arrangement either, and mostly progressed from it to using directional mics in the center and later on in additional L/R positions as well as a way to reduce the spacing needed between mics as well as increase "reach" for less-optimal recording positions. But that ~1 meter spaced four omni diamond-shaped array worked very nicely on stage, at stage-lip, and up close in the center of the audience.
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I've quite often used a center cardioid or hyper and placed it 4in or so in front of the usually subcardioid main pair after reading about it in several places. In a couple of problematic muddy sounding venues it does a lot to give a forward facing sound that helps combat too much room and cuts through the mids and highs a little. I've tried various tricks at the mix with various results but using a high pass at 500hz on the center has worked out great a few times. Seems counter intuitive but it worked to snap the center "into place" so to speak.
Similarly, I find the center pair doesn't need to provide much low-mid and bass in the mix, and feel it best to get the lower frequency content from the wider-spaced pair anyway. The somewhat typical low frequency roll-off of many super/hyper-cardioid directional mics that will tend to be used for the center pair sort of naturally achieves that, while more open-pattern mics which tend to be used in the L/R positions will provide more bass extension. All of the directional mics in my array have somewhat reduced low-frequency sensitivity - smooth enough that I can correct for it with EQ when needed, but I mostly just balance that content against the omnis to achieve the correct frequency balance. So that kind of filtering is somewhat built naturally into the array.
I suspect additional or more agressive high-passing or EQ may be helpful when using less spacing between the mics, since the closer together two mics which will be mixed together are the more potential they have for stepping on each other's toes, and filtering them differently is one potential way of easing any such potential conflict. For those EQing, carefully tweaking the center microphone content into shape after balancing everything else can be particularly useful for pulling out a bit more vocal clarity and detail from that part of the stereo image without adversely effecting everything else in doing so.
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Lee,
You have a link to that triangle mount? we need one
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Sure. I have a couple of them. I think one is a Manfrotto and one is a Impact, basically the same. Standard spigot socket with thumbscrew in the center. One came with a removable telescopic extension arm, the other I bought just as a foot. The legs are steel which makes it bit heavy, yet sturdy and it folds up complactly. I mostly use it as a foot, either on its own as a super low to the floor or table stand onto which the mic bar attaches, or in combination with an extension or two to get up between about 15" and 4'-5' high. Be aware that there is an alternate version that looks basically the same but is smaller in size, maybe around half the diameter. Pretty easy to mix them up if just looking at a photo - although If I recall the smaller one features a spigot stud in the center instead of a socket. Great little versatile folding foot, but I'd say not really wide enough to go unattended if going up, say 3' or higher. The addition of the two threaded holes in the other two legs which allow it to double as mic-bar just make it that much more versatile for me. Here's a couple of B&H links that popped up upon a quick search, but you can source it from pretty much everywhere:
Manfrotto version:
https://www.bhphotovideo.com/c/product/546481-REG/Manfrotto_003_003_Backlight_Stand_Black.html (https://www.bhphotovideo.com/c/product/546481-REG/Manfrotto_003_003_Backlight_Stand_Black.html)
Impact version:
https://www.bhphotovideo.com/c/product/1119713-REG/impact_ls_3sb_backlight_stand_base.html (https://www.bhphotovideo.com/c/product/1119713-REG/impact_ls_3sb_backlight_stand_base.html)
Smaller diameter Impact version (spec's say 14" diameter instead of 20"):
https://www.bhphotovideo.com/c/product/1651582-REG/impact_ls_bsb_m_mini_backlight_stand_base.html (https://www.bhphotovideo.com/c/product/1651582-REG/impact_ls_bsb_m_mini_backlight_stand_base.html)
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Here's a photo of the folding foot in use along with a single telescopic extension to create a "short stand", as posted in this thread about a month ago:
(https://taperssection.com/index.php?action=dlattach;topic=204186.0;attach=153257;image)
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thanks for the links.
I always enjoy the sounds of babbling brooks! Nice array you got there. >:D
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Now that I got my 4018s I’ll have to play with omt4. I ran 4015s din with 4018s pas for umphreys last week and liked how it turned out.
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Nice array you got there. >:D
Except for all the gaffer tape needed on it back then!
Good time up at AmpJam#1 at Spirit of the Suwannee last weekend. We had a good taping crew with a couple other tapers there running OMT4 type setups.
I was able to get my OMT8 rig back together a few days prior.. without the use of any gaffer tape! Hurrah to that long-term goal! Got it all done using shrink wrap, wire-tie zips, pipe clamps, and velcro cable-wraps. Still don't get around to remaking the center attachment hub, but may put that off for now as the current reworked version is working quite nicely. Will post some pics of the DIY "duck-back" covers I made a couple years ago that attach directly to each windscreen and eliminate the need for a single large umbrella along with the associated windage and visual problems, but fortunately the rain skirted past and they weren't really needed, so I only put up the bigger center one that covers the stereo shotgun for a couple sets. Will dig up some photos of that.
Reworked and nicely lit without any rain protection needed-
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Gorgeous shot! Mic pron!
Would love to hear the Mule set when ready.
Regarding center pair config and x/y vs m/s:
When m/s angle is just right and level in mix correct I think it's my favorite.
And x/y pas is drastically easier in the field and post.
I seldom record one show on its own lately, more likely tours/serieses, so the post production time investment is multiplied many fold.
For me, x/y ftw.
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Good time up at AmpJam#1 at Spirit of the Suwannee last weekend. We had a good taping crew with a couple other tapers there running OMT4 type setups.
I was able to get my OMT8 rig back together a few days prior.. without the use of any gaffer tape! Hurrah to that long-term goal! Got it all done using shrink wrap, wire-tie zips, pipe clamps, and velcro cable-wraps. Still don't get around to remaking the center attachment hub, but may put that off for now as the current reworked version is working quite nicely. Will post some pics of the DIY "duck-back" covers I made a couple years ago that attach directly to each windscreen and eliminate the need for a single large umbrella along with the associated windage and visual problems, but fortunately the rain skirted past and they weren't really needed, so I only put up the bigger center one that covers the stereo shotgun for a couple sets. Will dig up some photos of that.
Reworked and nicely lit without any rain protection needed-
That was a good time indeed! Always fun to check out everyone's different rigs and look for some new ideas. I taped most of the fest outside of a couple of the early sets and the Headhunters (which was solely due to a stupid mistake on my part related to a change in position and mics due to the strong possibility of incoming rain :banging head: ). For what was recorded, I ended up using 3 different configurations from the same general area FOB on a stand between 7-8':
DPA 2012 (Ch 1-2/DIN) + DPA 4061 (Ch 3-4/36” split) > MixPre 6
DPA 2012 (Ch 1-2/DIN) + DPA 4061 (Ch 3-4/36” split) + AKG ck63 (Ch 5-6/XY) > MP-2 > MixPre 6
DPA 2012 (Ch 1-2/DIN) + AKG ck63 (Ch 3-4/XY) > MixPre 6
I'm starting to process everything now after getting back to the real world of work and responsibilities, but should start getting some stuff posted in the next day or so.
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^Great to hang with you and the others up there. You've got some good material there to mess around with. You know it takes me forever and a day to get anything out, if I do at all, but I did get the Headhunters set and it sounds quite good straight off the recorder. That set in particular makes for a good example of how the portrayal of "cocktail audience chatter" can come across diffusely in such a way that less of the listener's attention gets drawn away from the music, even when the musical content isn't overly loud in comparison.
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Gorgeous shot! Mic pron!
Would love to hear the Mule set when ready.
Regarding center pair config and x/y vs m/s:
When m/s angle is just right and level in mix correct I think it's my favorite.
And x/y pas is drastically easier in the field and post.
I seldom record one show on its own lately, more likely tours/serieses, so the post production time investment is multiplied many fold.
For me, x/y ftw.
^ Thanks Chris. And thanks for sharing your experience in using the two different types of coincident pairs in the center. Last weekend while taping I had l a lot of thoughts on X/Y versus M/S in the center position running through my head, and of possible modular optimizations of my setup in the future based on that. More in a later post to follow..
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Got to try a little OMT tonight on a trio with an xy pair in the center and some wide cards spread at about 10", lip of stage (sorta, it was on the ground) about 1.5' from the musicians. Need to listen to it, but it was a fun experimental little compact setup.
Now this is some bad ass shit here: https://www.youtube.com/watch?v=VxC1xiIkxd4
VibrationOfLife, thanks for that video link. I'd not seen that one but have followed what Hyunkook Lee has been doing for a long time, both with ambisonics and distributed mic arrays. Cool stuff. However, I've yet to be personally convinced that height mics and height playback channels are particularly important for music, even if the goal is fully immersive surround playback. Capturing height goes past the point of diminishing returns I feel, even more so than the reproduction of it, but I've not properly experienced playback like that from properly recorded material! That said, I obviously find slicing up the horizontal plane with additional mic channels to be very useful, for both 2-channel stereo and surround. When I had my full surround playback system in action, routing the surround channel signals that were derived from rear facing mics and/or wide-spaced omnis with some filtering and delay applied to multiple playback speakers distributed around the room was very helpful in creating a truly immersive and realistic sounding diffuse/reverberant ambience with no audibly obvious gaps. It was more important to have full horizontal playback speaker coverage than to have full horizontal coverage from the mic array. From that experience, I can see how height speakers might be helpful, but it also convinced me that the diffuse ambient height content feeding them can be quite successfully derived from the other existing mic channels. Doesn't seem worth the effort to me, certainly not until the horizontal plane is well covered, which does matter and is a difficult enough sell on its own!
I will say that much of what they describe in that video about how solid and dimensional the playback sounds and how the bass reproduction is so much more natural, accurately reflects what I hear from my surround recordings when played back with the appropriate playback array. The ability to move around and face any direction with my eyes closed and have it sound just like I were doing the same at the event, including an accurate portrayal of the room acoustics in all directions (except up?) is astounding and quite involving!
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Ive not encountered any obvious phase issues with the two times Ive run like this. Both times I had the center mics forward anywhere from 4-8 inches. From everything I've read and what Gut has developed / documented. that seems to be the best approach - though others have noticed a smear when all four mics are not on the same plane. After listening to GSW and the LCR approach, I do think I'll go back to running the center as an XY pair a bit more, the single center channel here seems to be missing something that would be additive in a good way
Thanks for the details, impressions and links to the recordings!
I was able to give a brief listen to your God Street Wine recording yesterday, and it sounded quite good on Senn HD650 headphones streaming through my phone. Love the DPA 2015 sound, which is only improved farther with the addition of the 4011 in center of that arrayand to my ear, and very much liking the resulting solid stereo image. Although use of X/Y or M/S in the center rather than the single center mic isn't vital in your situation, as neither image placement nor smoothness across the L/R stereo image seems to suffer, it will be interesting to hear what X/Y center does using those mics. As you put it, "missing something that would be additive in a good way", seems a good description.
As mentioned, I generally bring up the center Side channel to taste, and there is always a somewhat subjective range of how much is best. With none of the Side channel included in the mix (equivalent to using just a single center channel) it sounds a bit "tighter, drier, and flatter", which can be helpful on some material with a lot of percussion transients, yet also tends to lack the extra bit of depth, dimension and stereo interest.. so I end up using at least a little bit of Side channel in the mix, essentially balancing "tight sharpness of image" against "dimensional openness". To my ear, it's too much Side channel in the mix (which presumably equates to too wide of an X/Y angle) that causes the mix to start to sound smeared, rather than a bit much forward spacing of the center mic or coincident pair. That's somewhat counter-intuitive since the Side channel mic remains coincident with the center channel mic, regardless of how far forward the two are placed.
I'll do some more extensive listening to this when I can, along with the Moe at Brooklyn Bowl recording you posted earlier. I intend to listen particularly for differences between using the 4018VL X/Y pair in the center verses the single 4011 for GSW.
Thanks again for the links to these recordings. The GST recording is not just an example of how this can sound good, but helps me confirm that the OMT progression remains on the right track and is applicable to higher quality mics like your 4015s, 4018s and 4011s, as well as the somewhat lesser quality miniature DPA mics I'm using.
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I’ll continue to share what I tape in here. I’ve got a number of shows coming up and appreciate the extra ears and perspectives on the results. On that note
I’m potentially going to a show tonight in a less than ideal room. Big, boomy reverberant. It’s also the Disco Biscuits and the low end will be pronounced for sure.
I’m intending to run the 4018VLs as the main pair spread out a bit like 30-45cm PAS and to my ears the 4018s are quite thin on the low end. I’m debating running the subcards XY in the center to simulate a center Omni to help capture the low end. Has anyone done something similar? Or would it be better to run the 4018s a bit more narrow PAS and put the sub cards on the outside in the traditional OMT config. Thoughts on either approach here?
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Where it isn't possible to locate the center mic(s) forward of the split omnis, is there any guidance on how much delay to apply to the omins in post to mimic the offset? e.g. sound moves 4 inches in about 0.3 milliseconds.
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I’m potentially going to a show tonight in a less than ideal room. Big, boomy reverberant. It’s also the Disco Biscuits and the low end will be pronounced for sure.
I’m intending to run the 4018VLs as the main pair spread out a bit like 30-45cm PAS and to my ears the 4018s are quite thin on the low end. I’m debating running the subcards XY in the center to simulate a center Omni to help capture the low end. Has anyone done something similar? Or would it be better to run the 4018s a bit more narrow PAS and put the sub cards on the outside in the traditional OMT config. Thoughts on either approach here?
That's a great question, one I'm still exploring and interested in.
Generally I like to put the more open pattern mics out in the spaced position. Partly because the spacing in combination with the deeper bass extension of the more open pattern helps in capturing "stereo bass" information down to a lower frequency, but also because the spacing allows more open pattern mics to be pointed more on-axis, even PAS when necessary, while still retaining stereo difference. The mics with tighter directional patterns can be spaced closer or coincident with each other and will still produce useful stereo difference when used at the same angle. That's "traditional OMT", taking advantage of the natural attributes of the mics, yet is sort of built atop a foundation of decent room acoustics.
But in a challenging room (boomy, reverberant, a bit too far back) I see advantages of going the other route. Supercards used in the spaced position and angled for PAS will cut the boom and maximize clarity from the PA. In the center position, close-spaced or X/Y subcards in PAS will produce far less stereo difference information, but that's probably OK as that essentially shifts things along a trend-line to being more like a single center channel mic, similar to using less Side channel or a very narrow X/Y angle. If you are using less center pair than outside pair in the mix, that resulting balance will also reduce the boom.
Subcards are very smooth off-axis so they can be angled very widely, even 180-degrees apart, and that would normally be helpful when not spaced very much or at all - as they will be in the center position, however I think you'll want to keep both pairs in PAS or close to it because of the room.
If really boomy and reverberant, consider using the 4011 cardioids in place of the 4015 subcards, arranged with the supercards flanking and cardioids in X/Y or the opposite way around.. both pairs in PAS or close to PAS.
In terms of boom/reverberant reduction, I suspect it goes like this, from maximum to minimum:
1) supercards wide, cardioids X/Y center (max)
2) cardioids wide, supercards X/Y center
3) supercards wide, subcards X/Y center
4) subcards wide, supercards X/Y center
5) subcards wide, cardioids X/y center (min)
My anecdotal experience-
I had good results in a somewhat boomy boxy room running Gefell M21 supercards @ 50cm/90deg + a Gefell M94 cardioid Mid in the center M/S pair. That arrangement is somewhat like you mention in that the more directional pair was used as the outside flanking pair and the more open pattern was used in the center as Mid.. well sort of like you mention. After converting the Mid/Side pair output to L/R, the virtual polar patterns of the resulting X/Y pair were actually more supercard like than cardioid, so it was more or less equivalent to using spaced supercards with a supercard X/Y pair in the center. That made the array very directional with both pairs more or less in PAS (outer pair at 90-deg pointed them maybe 10-deg outside stacks, center pair angle being determined by M/S ratio, which ended up equating to PAS or just inside stacks).
^
I intended to switch that around the other way with the cardioids @ 50cm/90deg + supercard Mid in the center for another show in the same room but unfortunately never got around to doing that.
I decided to set it up first using the M21 supercards in the outer flanking position because years ago I'd successfully used a 3-mic L/C/R arrangement of supercards (ADK TLs set to supercard mode) from the same position in that room, and this arrangement was most similar to that. I used the folding foot posted about above, flipped over to form an L/C/R mic-bar for both of these setups.
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Found an example of the setup above that I posted about in the previous thread - supercards spaced, cardioid Mid/Side in the center, using the folding foot as mic-bar, in that room. Here's the post: https://taperssection.com/index.php?topic=191953.msg2373463#msg2373463 (https://taperssection.com/index.php?topic=191953.msg2373463#msg2373463)
And here's a photo of the mic-setup from that post. Double extension was super-clamped to a stair case railing directly in front of the board, which nicely pushed the mics forward a bit into the room a bit more, but produced that crazy mic-bar angle. Mics were angled up toward the PA to cut audience chatter.
(https://taperssection.com/index.php?action=dlattach;topic=191953.0;attach=145374;image)
Here's another of the same setup the following night at a different venue. Stand vertical this time using both folding feet, one as mic bar as before, the other at the bottom in place of the superclamp, sitting atop a box behind the soundguy to get above heads.
(https://taperssection.com/index.php?action=dlattach;topic=191953.0;attach=145379;image)
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Where it isn't possible to locate the center mic(s) forward of the split omnis, is there any guidance on how much delay to apply to the omins in post to mimic the offset? e.g. sound moves 4 inches in about 0.3 milliseconds.
Best to just try it and see how it sounds. 20cm or ~8" equates to around half a millisecond. Try more, try less. Go with whatever works.
Remember that delay is different than physical spacing, except for wave-front arrival from a single direction, so in addition to listening to it's effect on the main sound of interest arriving stage and PA, also listen for the effect on reverberance, audience, and rear and side sound arrival.
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After many years of 4 channel recording and recently getting into OMT-4 with cards and omnis, this was my first time trying OMT-6 with DPA 2012 cards, DPA 4061 CORE omnis and AKG ck63 nBob actives hypers.
https://archive.org/details/lettuce2025-03-07.DPA-AKGMatrix
Lettuce
3/7/2025
Suwannee Amp Jam #1
Spirit of Suwannee Music Park
Live Oak, FL
Source: Ch 1-2: DPA 2012 (DIN/Ch 1-2) + Ch 3-4: DPA 4061-OC-C (36" Split/Ch 3-4) + Ch 5-6: AKG ck63 (XY) > nBob actives > MixPre > MixPre-6 (24/48) > SD Card
Location: FOB/DFC (On stand @ ~7.5')
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^ Thanks for the link. What are your thoughts about it and how it compares to what you've been doing with 4 channels?
I gave a brief listen at lunch today streaming archive>phone>cheap USB-dongle-dac>SennHD650, and found I needed to apply some EQ using the Archive WinAmp player, after which it sounded nice. Used a smooth sine-like curve, flat at both extremes and at 1kHz, down below 1kHz in the high-bass/mids, up above 1kHz in the presence range. Not an overly unusual correction for live concert recordings, but a bit more than I typically use. Not sure how much of that is due to the response of my playback chain using the cheap dongle, the responses of the directional mics, or mic array geometry. If you run this again and have the ability to do so, try spacing the 2012 pair spaced wider than DIN to leave room for the X/Y pair in the center. In my mixes the omnis + center pair get balanced first, and the wider than normal near-spaced pair adds sort of a zoomed-in upfront presence boost which can at times be somewhat SBD-like.
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[snip..] Regarding center pair config and x/y vs m/s:
When m/s angle is just right and level in mix correct I think it's my favorite.
And x/y pas is drastically easier in the field and post.
I seldom record one show on its own lately, more likely tours/serieses, so the post production time investment is multiplied many fold.
For me, x/y ftw.
[snip..] Last weekend while taping I had l a lot of thoughts on X/Y versus M/S in the center position running through my head, and of possible modular optimizations of my setup. More in a later post to follow..
Rehash on thoughts about the center coincident pair..
For PA-amplified taping, X/Y might be best.
> Tends to work well with a standard 90-deg X/Y angle.
> May be further optimized by PAS angling each X/Y directional mic to be directly on-axis with the PA on each side, possibly in combination with a stereo width adjustment afterward to optimize playback image.
> Doesn't require a fig-8 mic.
> Doesn't require any decoding (unless you count making a stereo width adjustment)
Otherwise M/S:
> More compact and easier to mount (for me at least, using two mics in parallel or a single-body M/S mic requiring only a single mic clip and single 5-pin XLR cable).
> No need to consider/configure X/Y angle at setup.
> May be best for OMT6+ where the Mid mic serves double duty as the center mic of the near-spaced L/C/R stereo triplet.
> Less need for a matched pair.
> Side channel added to taste (essentially the same as making an X/Y stereo width adjustment, except it forces one to do so).
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Where I was thinking of taking my OMT8 setup-
I like the AT BP4029 Mid/Side shotgun I've been using in the center for the past year or so. Along with providing the sound I wanted (a more SBD-like center with increased presence and reach) it's convenient and has been working well. But at 15" long it's a bit large. I'd like something shorter. Also, there are times where I'd like to change the pattern of the Mid along with the pattern of the flanking L/R mics in the near-spaced L/C/R triplet.
So first of all, I'm thinking I'll set it up to easily swap in/out the significantly shorter M/S pair I was using previously (DPA 4098 Mid / Niaint X8 Side). I keep that pair gaff-taped together so that it acts like a single integrated M/S mic and is very compact, fitting inside a single Movo WS60 windscreen. Now thinking I may make a short, rigid, XLR 'Y' adapter (2 x 3-pin XLR-F > single 5-pin XLR-M) to enable use of the same 5-pin cable and single mic clip for either center pair. Will also make swaping in/out different fig-8s and different Mid mics easy.
I'd use that feature to adapt the rig to different situations. Shotgun Mid where needed from farther back, supercardioid Mid when closer.
Taking it further.. is going to have to wait for a following post, gotta run.
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^ Thanks for the link. What are your thoughts about it and how it compares to what you've been doing with 4 channels?
I gave a brief listen at lunch today streaming archive>phone>cheap USB-dongle-dac>SennHD650, and found I needed to apply some EQ using the Archive WinAmp player, after which it sounded nice. Used a smooth sine-like curve, flat at both extremes and at 1kHz, down below 1kHz in the high-bass/mids, up above 1kHz in the presence range. Not an overly unusual correction for live concert recordings, but a bit more than I typically use. Not sure how much of that is due to the response of my playback chain using the cheap dongle, the responses of the directional mics, or mic array geometry. If you run this again and have the ability to do so, try spacing the 2012 pair spaced wider than DIN to leave room for the X/Y pair in the center. In my mixes the omnis + center pair get balanced first, and the wider than normal near-spaced pair adds sort of a zoomed-in upfront presence boost which can at times be somewhat SBD-like.
Thanks for the input! When I was mixing the tracks, I found that adding in the XY ck63s provided more presence in the center than when I didn't include them. The mount I use for the 2012 pair is an SRS mount that isn't adjustable. I do have the original mic clips/holders that came with the set that can be used on a T-bar, so those will be in action for my next OMT-6 outing to increase the spacing.
You are definitely correct in that some EQ makes it sound better. Most everything I record just gets click removal for applause, compression, normalizing and fades. I've tried EQing in the past, but never felt comfortable with what the outcome and took it out of my workflow. Looks like it's time to start working on some EQ skills for future releases...
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^ so agree on eq being tricky.
I don't eq much except for applying a reverse curve normalization on the compressed track when using ny compression. That material is only heard when the main track gets super gquiet so not too noticeable.
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^ so agree on eq being tricky.
I don't eq much except for applying a reverse curve normalization on the compressed track when using ny compression. That material is only heard when the main track gets super guiet so not too noticeable.
I know we are veering OT, but I also try not to use any EQ in my OMT mixes and never used it in my cassette transfers to digital while processing. When I started on my 200+ show GD project I asked Charlie Miller for advice and he had only a few rules of thumb but no EQ was one of them. He said, "the listener can choose to use EQ on playback". fwiw
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I agree with all that. Having the listener apply whatever the EQ they need is always right. And if it's just a straight two-mic-pair recording there also is a sort of a broad "taper documentation / comparison" argument for not EQing. I'm not opposed to going against that to make for a more enjoyable recording, but if I do, I want to be careful about what changes I make.
While that argument also applies here to where we are critiquing the OMT technique ourselves and our implementations of it as much as enjoying the end results, I feel it applies less broadly to OMT recordings released to the outside world, simply because by mixing multiple mic channels down to stereo in we are already engaging in a degree of taper trickery that veers away from the "straight traditional taper documentation mode" of doing things.
I've gravitated to the mics I'm currently using in part because most of the time they naturally work well in these arrays without needing EQ. I know I can make it sound even better by applying careful EQ, but rarely end up doing it - partly because doing so is a hassle, partly because its a challenge to make sure my EQ choices will translate as intended. But knowing what is possible and where I can take it to make it as good as possible is important to me. And sometimes corrections are necessary and making them becomes the right thing to do. I see it as sort of a Goldilocks situation: In addition to the things best left for listeners to fix for themselves, there are things that can be fixed, things that should be fixed, and things best left alone.
Personally, while my ultimate goal is a recording that's well mastered so that a listener would only need to EQ to suit their playback system and listening preference, and such mastering also includes dynamics, imaging tweaks, whatever.. that shooting for perfection effort isn't happening often.
I instead shoot for setting things up to work well enough using only the simple mixer built-into the recorder, and if I can get that to happen I'm happy. Not perfectly mastered, but good enough that only a bit of simple EQ correction, ideally via simple tone controls gets it close enough to where it needs to be for enjoyable listening.
Some recordings are more of mess and require more complex correction, more than a listener would normally be expected to make and I feel those are best fixed before getting to the listener. Maybe they require more "surgical" EQ rather than a broad correction, or EQ to only to one set of mic channels and not the others, or different opposing EQs on different channel pairs, or whatever.
The ones that aren't a total disaster without complex correction, but also are not right enough to be enjoyable after a simple tone control / graphic EQ correction are the ones where I sometimes struggle with the decision of what to do or not.
200+ show GD project
These decisions become more poignant when working on big projects and other taper's recordings. Handling big numbers of shows like that requires doing less simply for practical as well as philosophical reasons. Is a lot less difficult to make a big effort when working on just a handful of one's own recordings, and even then it can be challenging to know how far to take it.
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I found that adding in the XY ck63s provided more presence in the center than when I didn't include them. The mount I use for the 2012 pair is an SRS mount that isn't adjustable. I do have the original mic clips/holders that came with the set that can be used on a T-bar, so those will be in action for my next OMT-6 outing to increase the spacing.
Right on. I can see that. Lots of ways to mix these.
What strikes me is that the X/Y and DIN pairs are relatively closely positioned to each other in that setup, which can make the two pairs more likely to interact in ways that effect tonal response when they get mixed together. A bit more spacing between the two pairs may allow them to be just different enough that they combine with less tonal interaction (if that is what's going on tonally). I take it you are working up your mix by first balancing the omnis and 2012 DIN pair, then add in the center X/Y to taste. If so try it the other way- start with the omnis and add the X/Y to that first, then after getting that combination nicely balanced, bring in the near-spaced 2012s to taste. That progression order tends to work well for me both in terms of image balance and in terms of tone - the image sort of gets balanced first with omnis and center pair, and the near-spaced pair mostly adds up-front presence and energy, but also additional stereo interest. In this way you may end up using more X/Y and somewhat less DIN than the other way around (just guessing about that), which might effect the tonal balance without EQing. If you try it let me know if it works out any different to your ear.
Using more spacing between the 2012 pair next time if you are able will likely help both in terms of imaging and tone by getting that pair farther away from the center pair. In moving from OMT4 to OMT6, think of the omnis + X/Y center pair part as the primary OMT4 part and the near-spaced pair as the new element being added as supplemental flavoring, even if it's the X/Y pair that is actually the new addition for you. And in that way see if you get the additional presence, energy, and up-frontness from adding in the near spaced pair to taste, rather than from adding in the X/Y center pair instead.
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I take it you are working up your mix by first balancing the omnis and 2012 DIN pair, then add in the center X/Y to taste. If so try it the other way- start with the omnis and add the X/Y to that first, then after getting that combination nicely balanced, bring in the near-spaced 2012s to taste.
That's exactly what I was doing. Since I generally use the 2012 DIN pair and/or 4061 omnis when taping 4-channel, I was balancing those first and then adding in the XY ck63 for more flavor. Your idea of working up the omnis and XY and then adding in the DIN pair will be my next move. I never thought of blending the sources that way, but it makes sense and I'd like to hear how that would sound. I've still got a few OMT-6 sets left from the Amp Jam, so I'll use this method with the mix on those and see what develops.
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Try it both ways. I like to go back and forth like that when working on a mix, building it up one way, tearing it back down and doing it again the other way, as that tends to lead to different choices and end results. I may end up with two somewhat different mixes that way, both good sounding, that I can then compare against each other to gain insight into the reasons I like one more than the other. That process also informs how I go about making future mixes. In either case, I like to do a lot of muting and unmuting of the various stereo pairs while assessing a mix to listen for how it hangs together and better understand what each addition/subtraction is doing in the mix.
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Boy do I have a OMT mixing story for you guys.
One final mix result is here:
https://archive.org/details/eggy2025-03-13.dpa4060akgc426ck61
I "mixed" that one by using the Mid cardioid microphone of a AKG c426 MS pair, using that as center, then added the DPA 4060 omnis which were spread about 5 feet apart, 2.5 feet from center. I then added a bit of the AKG ck61 cardioids spread about 4 feet apart, 2 feet from center in an AB pattern (facing straight at the stage). So I called it an OMT5 mix. I matched each stereo pair to be -6dB from 0, then made the Mid channel at -4dB from 0 for the final "mix". I like the sound of the vocals and ambiance but...
After posting that I thought there was not enough low end in the result, so I went to mix one where I did the Side channel manual decoding which actually made the final mix pretty different sounding. it is almost OMT7 with the side pair made into Left/Right.
I will upload that one to LMA tonight or tomorrow and let you guys know via editing this post.
OK, here is the mix which adds the Side content and is a bit different in Omni vs inside AB cards content also. (More Omni, less cards vs the first mix)
https://archive.org/details/eggy2025-03-13.dpa4060MSc426ck61
If anyone hears a difference let me know WHAT you hear. I have my opinions I will share after a few others share their opinions.
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^ Thanks Rock', I've been working a tradeshow all week but will give that a listen once I return home.
[snip..] Last weekend while taping I had l a lot of thoughts on X/Y versus M/S in the center position running through my head, and of possible modular optimizations of my setup. More in a later post to follow..
^ Returning to those thoughts. What I'd really like is a modular mid/side setup using the same "end-address single stereo pencil mic" arragement as a stereo shotgun, except with the ability to swap out the mid capsule for alternate patterns. It would consist of a compact stereo mic body with 5-pin XLR at one end and built-in fig-8 at the other that has a threaded capsule coupling on the end for attaching whatever mid capsule you prefer. Using a supercard, cardioid or omni capsule Mid, the pair would fit in a single compact Movo windscreen. With a short interference tube shotgun capsule attached, it would fit in a single slightly longer Movo.
..and with a second fig-8 capsule attached it would transform into a side-adress Blumlein stereo mic.
In my OMT setup, I could put a short shotgun Mid in the center pair position between nearspaced L/R supercards like I'm currently doing, or switch back to using supercards in all three positions L/C/R positions like I was doing previously, or use any other combination including a pair of short shotguns in PAS in the nearspaced L/R positions along with a wider pattern Mid.
That last configuration may prove best when recording PA amplified material from a recording position farther back in the room, as the L/R positions which seem to provide the additional up-front presence, clarity and punch would be maximally focused on the PA while the center pair provides the solid center, ambient width and "glue".
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In any case it would allow for maximum flexibility using the minimal number of mic capsules, and easy transformation to a more compact arragement when needed.
Such a modular Mid/Side stereo microphone with interchangeable Mid doesn't currently exist to my knowledge, but the B9 stereo Blumlein mic is very close, lacking only the ability to swap out the figure-8 closest to the end for a alternate pattern.
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Wonder if there are isues when a pair of mics is facing 180º away from the others? Do you flip the phase in post?
TIA
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^ The short answer is typically no. But whatever works in the mix. What sounds right is right.
Consider a single pair of L/R stereo pair of cardioids. Use whatever stereo angle you like between the two. Pointing them 180º apart would be extreme but you wouldn't invert the polarity of one of them because the angle increased to 180º. In that case the mics are being angled along the Left/Right axis, but same goes for angling them along any other axis. If the goal is pickup of content arriving from that direction, you probably don't want to invert polarity.
Long answer exploring why in more depth, feel free to ignore if confusing..
Fundamentally -
An omni is a "pressure sensor" regardless of which direction it's pointed. Positive pressure at the diaphragm produced by a wavefront arriving from any direction produces a positive signal voltage output. Inverting polarity of an omni will tend to cause cancellation of low frequency content when combined with the other mics of the array which are not polarity inverted.
In contrast, inverting polarity of a figure-8 flips its orientation to the opposite direction. The fig-8 pattern remains the same, but now a positive output voltage will be produced for wavefront arriving from the opposite direction. Inverting polarity of a rearward-facing fig-8 produces a forward-facing fig-8 pattern.
A cardioid is an equal combination of omni and fig-8 components from the same point in space mixed together. Inverting polarity of the microphone output inverts both it's omni and fig-8 components at the same time. Prior to the polarity inversion those components are combined in the same way as before - the positive output lobe of the fig-8 component mixes additively with the omni component, doubling output on-axis, while the negative output lobe of the fig-8 component mixes subtractively with the omni component forming the rear-facing null. Since the polarity of both components is inverted, the polar pattern faces the same direction as before, but with inverted polarity. When mixed with the other microphone channels the inverted polarity output of this microphone will combine subtractively wherever the signal is sufficiently phase-coherent across the summed channels, which with a near-spaced pairs will tend to occur at low frequencies. Were the signal is not phase coherent across the summed channels it will mix additively.
So.. inverting polarity of a near-spaced stereo pair pointed in the opposite direction will probably cause the mix to sound leaner in the bass where the content is mostly phase coherent in all mic channels, but probably won't sound much different at high frequencies where the content and phase-relationship between in the various channels is different.
Taking it further-
If instead we were able to invert polarity of only the fig-8 component and not the omni component before the two are combined inside the microphone, the resulting cardioid polar-pattern would then face in the opposite direction, yet the polarity of the microphone's output would remain the same. That's essentially what is happening when converting Mid/Side to Left/Right. The fig-8 Side channel's contribution to the Right channel is made with inverted polarity, so the Right virtual polar pattern faces the opposite direction of the Left virtual polar pattern.
If instead we were able to invert polarity of only the omni component and not the fig-8 component, the polar-pattern would also face the opposite direction, AND the combined output would have inverted polarity.
That's essentially what's going on with Ambisonics, where multiple microphone capsules are arranged so as to be as coincident as possible and pointed in all directions. With all the mic capsules positioned in nearly the same point in space, their outputs remain phase-coherent to a sufficiently high frequency that the virtual patterns which result from combining their outputs in specific ways via the manipulation of polarity and level maintains the polar pattern shape up through a sufficiently high frequency. The closer the arrangement of capsules in an ambisonic mic, the higher in frequency it is able to maintain a coherent pattern.
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Gut, I finally got a chance to run the OMT4 setup with the 4018s on the outside about 2' spread, 30* angle with the 2015s in the center as an XY pair at 90*. I had the 4018s about 8 inches in front of the subs in this case. The results are excellent. Big caveat this is a great sounding room so most tapes sound great here. I was keen to try to this out for the times where I will have a less than ideal room. The hypers on the outside sounded quite nice actually but lack any depth and sound thin to my ears. They are, as expected, focused, detailed with good punch and clarity, lacking low end response, etc. The subs XY in the middle by themselves sound quite horrible tbh. The main thing I wanted to test here is if the subs XY in the center added anything of value. When the 4 are mixed down they add quite a nice low end and provide some depth. The sum is definitely greater than the parts. I will post the raw and processed files later today. I ended up with a heavy hyper mix, about 75% with just enough of the subs to give some low end presence and space. Quite nice. Look forward to trying this in a less than ideal room to see how it holds up.
Also because I only have one set of DPA-A Bodies, I have to choose between hypers or card caps with the 2015 being a separate stand alone pair. So it needs to be some combo of subs and then either hypers or cards which is why I went hypers outside, subs inside.
Edit: Updated with links to the raw and matrixed files
https://drive.google.com/drive/folders/1dIvKOUiE_3DJlB0iU5x5VKlrHiRGyjsm?usp=drive_link
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Big thanks for the feedback and happy to hear it worked to satisfaction! Your description of the sum being greater than the parts parallels my experience. I think to really work optimally in combination its necessary for each of the pairs to sacrifice working ideally by themselves.
Good to hear the subcardioids worked well in the center X/Y pair position, since despite my speculation that it should provide the right things to work in the mix that's something I've not actually tried myself. I wouldn't expect the X/Y pair to sound great by itself - the subcards aren't directional enough to provide the necessary channel separation to work really well as an individual coincident stereo pair, but in the mix it's no longer necessary that they provide sufficient channel separation that would be needed on their own. Their contribution is instead anchoring the center and enhancement of the limited sense of dimension, depth and bass-extension from the more PA-directed supercards.
What X/Y angle did you use? Any thoughts about X/Y in the center in comparison to the single forward facing supercard you used previously there? ..recognizing of course that the different patterns used on the recordings will also sound quite different. One interesting thing to do if you've not already messed around with it is to play with panning the X/Y pair in various ways. I assume you have the pair hard panned L/R in the mix, which makes sense, especially using subcardioids. However, if you pan both to center you emulate use of a single mic in the center with a polar pattern somewhat wider than either mic of the X/Y pair. I find it useful to dial in that panning after getting the levels of both pairs where I want them. Doing so adjusts the stereo blend across the image and the overall sense of width. Also particularly useful is the ability to set the level and panning positions of the individual X/Y channels differently as needed to help correct an off-center recording.
If you decide to use this arrangement regularly I think you'll get good milage out of it. To best adapt to different situations, I suspect it might be helpful to swap the position of the 4015's and 4018's depending on the room. Using the 4018 supercards in the outside position should help in more challenging rooms, while using the 4015's on the outside may potentially sound even better in really good rooms. That's partly because, just like you mention doing, I also tend to treat the wide pair as primary and bring up the center pair at a lower level in support of it. So it makes sense to use the supercards in the outside position in situations where you might have used a single pair of supercards, and to use the subcards in that position where you would expect a single stereo pair of subcards to work well. But that said, if you find using the supercards on the outside achieves the sound you want in great sounding rooms as well there may be no need to switch back and forth.
I hope to be able to give a listen to tonight..
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Boy do I have a OMT mixing story for you guys.
One final mix result is here:
https://archive.org/details/eggy2025-03-13.dpa4060akgc426ck61
I "mixed" that one by using the Mid cardioid microphone of a AKG c426 MS pair, using that as center, then added the DPA 4060 omnis which were spread about 5 feet apart, 2.5 feet from center. I then added a bit of the AKG ck61 cardioids spread about 4 feet apart, 2 feet from center in an AB pattern (facing straight at the stage). So I called it an OMT5 mix. I matched each stereo pair to be -6dB from 0, then made the Mid channel at -4dB from 0 for the final "mix". I like the sound of the vocals and ambiance but...
After posting that I thought there was not enough low end in the result, so I went to mix one where I did the Side channel manual decoding which actually made the final mix pretty different sounding. it is almost OMT7 with the side pair made into Left/Right.
I will upload that one to LMA tonight or tomorrow and let you guys know via editing this post.
OK, here is the mix which adds the Side content and is a bit different in Omni vs inside AB cards content also. (More Omni, less cards vs the first mix)
https://archive.org/details/eggy2025-03-13.dpa4060MSc426ck61
If anyone hears a difference let me know WHAT you hear. I have my opinions I will share after a few others share their opinions.
Anyone get a chance to listen to these? With all our talk of mixing the separate channels, I thought some folks might have time and/or an opinion. If anyone does, let me know either in this thread or PM.
I'm also working on my database in Excel format to indicate how many OMT recordings I have on LMA.
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I've not yet had a chance yet, but am hoping to listen tonight along with FOCKER's recording.
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What X/Y angle did you use? Any thoughts about X/Y in the center in comparison to the single forward facing supercard you used previously there? ..recognizing of course that the different patterns used on the recordings will also sound quite different. One interesting thing to do if you've not already messed around with it is to play with panning the X/Y pair in various ways. I assume you have the pair hard panned L/R in the mix, which makes sense, especially using subcardioids. However, if you pan both to center you emulate use of a single mic in the center with a polar pattern somewhat wider than either mic of the X/Y pair. I find it useful to dial in that panning after getting the levels of both pairs where I want them. Doing so adjusts the stereo blend across the image and the overall sense of width. Also particularly useful is the ability to set the level and panning positions of the individual X/Y channels differently as needed to help correct an off-center recording
I ran them XY at 90 in the center. I have dedicated mounts at that angle so playing around with angles will require some new gear. I hadnt thought about doing anything with panning. Will play around with that, but yes it was hard left and right in the matrix above. The other variation of this subcard setup for the center I was thinking about what something akin to the Healy Method, basically back to back pointing diredtly out to the sides. I will give this a shot just to see how it pans out. Playing around with these different setups has brought some additional enjoyment to this sport.
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The nice thing about xy is you can adjust width in post just like midside, so you don’t really need to change the actual orientation.
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The nice thing about xy is you can adjust width in post just like midside, so you don’t really need to change the actual orientation.
Is that just done through the panning? How would you go wider than 90 degrees if you’ve panned full left and right with the mics set at 90? Or is it only to make it more narrow?
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You can really only go inward with panning/blending, but with a mid side you have all the things.
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Its very cool that the physical angle used between a pair of X/Y mics and the virtual angle which results between the two mic patterns in the mix can be different, as it's something we can use to advantage when recording and afterward in the mix, even playing the two off of each other to some extent.
The nice thing about xy is you can adjust width in post just like midside, so you don’t really need to change the actual orientation.
Right. We can re-adjust the balance afterward somewhat, which can help in fixing it if not right, further optimizing it if already pretty good, or even allowing us to intentionally use an X/Y angle that we know wouldn't work well on its own without a re-adjustment because it can be made even better after the re-adjustment. More on that below..
Is that just done through the panning? How would you go wider than 90 degrees if you’ve panned full left and right with the mics set at 90? Or is it only to make it more narrow?
You can go both more narrow and more wide than the physical X/Y angle. Panning a stereo pair wider than full Left / full Right equates to mixing in some of the opposite channel with inverse polarity to either side. But going either way to the full extreme, the result will be a mono signal. More below..
You can really only go inward with panning/blending, but with a mid side you have all the things.
We can do it in a few different ways, including using and enhanced version of stereo panning/blending.. but we don't quite get all things. There are a few important limitations. To get all things requires taking it one step further from Mid/Side into ambisonics. More below..
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90deg XY is able to be mathematically converted into Mid and Side, allowing the same techniques on both.
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^Sure, 90deg is the safe choice and a good place to start for OMT. But any X/Y angle can be Mid/Side manipulated and there may be some advantages in using a different angle.
First how for the others:
Easiest way to make the angle/width re-adjustment is using an enhanced stereo-balance control on the stereo channel of the mixer for the X/Y pair, if that's available. I use Samplitude and it provides an advanced option on the stereo balance pot control of stereo mixer channels which allows one to alter the stereo width of the pair rather than the L/R channel balance. In that mode, the pan/balance pot becomes a stereo-width adjustment pot. Rather than shifting balance left/right, it simultaneously pans both channels closer to center as the pot is rotated counter-clockwise, or pans them "over-wide" beyond the original full Left / full Right pan pot positions as the pot is rotated clockwise. To do that, as the pot is adjusted to a "wider than normal stereo position" it begins mixing in some of the opposite channel with inverse polarity. This is sometimes called "super-stereo" or "over-wide stereo". Pushing it all the way we end up with an equal amount of each channel mixed into the other, but with opposite polarity. The result is the identical mono "difference signal" in both channels except with opposite polarity - exactly the same the Side channel from a Mid/Side pair and how that gets used by routing it to both Left and Right channels equally but with opposite polarity.
Aside- If familiar with the "squiggle cloud" of a goniometer display (https://en.wikipedia.org/wiki/Goniometer_(audio)), recall that a mono signal produces a vertical line on the display. Panning that mono signal Left or right angles the line to the left or right on the display as level sent to both output channels changes. Fully panned hard right or left with nothing in the opposite output channel places the line at a 45 degree angle. Going "over-wide" angles the line past 45 degrees by starting to mix in some of the opposite channel with inverse polarity. Going all the way to that "over-wide" extreme we end up with the same content in both channels except fully out of polarity with each other, producing a horizontal line. A stereo signal instead of a mono one behaves similarly, but instead of a straight line it produces a squiggly cloud that dances around. The fatter the squiggle cloud, the more stereo stuff that is occurring. The cloud might tend to spread out more along the vertical axis which is indicative of a narrow panned and mostly mono stereo signal, might tilt toward the left or right indicating that the balance is tilted that way, or might be wider than it is tall which indicates that the content is more out of polarity than in polarity across both channels because it has more Difference (Side) content than Sum (Mid) content.
Another way to do it is using a stereo width adjustment plugin tool. I commonly use Voxgengo's free MSER plugin which is a Mid/Side tool that has the ability to do some other stuff as well, but can be set to simply convert L/R to Mid/Side, let you to make an adjustment to the level level of Side (Sum) verses Mid (difference), then convert back to L/R again.
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The what/why:
We can convert back and forth between X/Y (Left/Right) and Mid/Side (Sum/Difference) without any loss as many times as we like if we make no change in the level of one channel verses the other. Or we can switch from L/R to Mid/Side, change the level of Mid verses the level of Side (changing the ratio between the two) and switch back to L/R again, incurring only a slight loss which will probably be negligible depending on the extent of the change. We then end up with an altered virtual X/Y angle AND an altered virtual polar pattern than whatever we started out with. If we want to take that output and re-adjust back again without reverting to the source material, we can't go too crazy with it without loosing information and the ability to get back to where we started - if we were to adjust the ratio all the way to 100%Mid or 100%Side, we'd end up throwing out all the information from the other channel and would be left with only the mono sum (Mid) in both channels or the mono difference signal which will be out-of-polarity in both channels.
90 degree X/Y is a good safe starting point because its right in the middle Goldilocks zone between all (180 deg) and nothing (0 deg).
Although we can usefully re-adjust the virtual angle afterward to a useful extent, the physical angle used between an X/Y mic pair when making the recording still matters for a few reasons:
1) If not tweaking/re-adjusting stereo width of the X/Y pair afterward, the physical angle you use when recording is what you end up with in the mix. 90-degree X/Y works pretty well in OMT, although a wider angle often works better for an X/Y pair used on its own in the same situation.
2) Changing the physical X/Y angle alters the virtual Mid pattern. 100% Mid equates to both channels summed together. If we used no X/Y angle at all (both mics parallel to each other) the virtual Mid would have the same polar pattern as either of the two microphones. The wider the physical X/Y angle, the wider the virtual Mid pattern becomes when the two are summed. If we were to use a 180 degree X/Y angle, the virtual mid polar-pattern that results would be omnidirectional regardless of the physical polar pattern of the microphones (Exception is fig-8's, which would cancel out entirely producing no virtual Mid). This is a big one if the intent is isolating pickup of the center pair to direct sound arriving from the stage and PA as much as possible. A pair of supercardioids at a 90 deg X/Y angle do not produce a supercardioid Mid, but something more like a cardioid pattern.
3) Response of most microphones is best directly on-axis. It makes sense to orient them on-axis with the source of interest when possible, particularly when we are attempting to attenuate off-axis pickup by using a highly directional polar pattern.
We might leverage 2 and 3 a bit by pointing the X/Y pair directly at the PA. The resulting X/Y angle will probably then be less than 90 degrees. That's good in that it keeps the mics on-axis with the source, and because it makes the virtual Mid more forwardly directional. We can sum the X/Y pair to mono and get a tighter virtual single center mic pattern than we otherwise would have achieved. But maybe its not so good if the stereo width that results from that narrow PAS angle is insufficient. In that case we can re-adjust the virtual angle afterward to regain the stereo width we want from that pair and still have the physical mics pointed advantageously ..within limits.
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[snip..] with a mid side you have all the things.
You gain some useful degree of adjustment. But the useful range is limited by a few things. One is that virtual X/Y angle and virtual X/Y polar patterns are inextricably linked. If we change one we change the other along with it. The wider the virtual X/Y angle, the narrower the virtual polar patterns. At one extreme (100% Mid) the virtual polar pattern is the combined pattern of both mics summed together with their physical patters overlapped by whatever X/Y angle was used, and for any practical X/Y angle greater than 0 degrees, that pattern will always be wider than the physical polar pattern of the mics being used, as previously mentioned. At the other extreme (100% side) the resulting virtual polar pattern will be a side-ways facing fig-8.
Unfortunately that trend is the opposite of what tens to be desirable for an X/Y stereo pair. As the X/Y angle is made narrower, we'd like the pattern to be narrower too, and vice-versa. Assuming a Blumlien pair of fig-8's works optimally at 90degrees, we'll probably want a wider X/Y angle than that if using supercards in place of the fig-8's, and wider angle still if using cardioids.
Ambisonics goes further in that it allows us to alter virtual pattern and virtual X/Y angle independently of each other. It gives you all things.. at least from one-point in space.
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Gut, I finally got a chance to run the OMT4 setup with the 4018s on the outside about 2' spread, 30* angle with the 2015s in the center as an XY pair at 90*. I had the 4018s about 8 inches in front of the subs in this case. The results are excellent. Big caveat this is a great sounding room so most tapes sound great here. I was keen to try to this out for the times where I will have a less than ideal room. The hypers on the outside sounded quite nice actually but lack any depth and sound thin to my ears. They are, as expected, focused, detailed with good punch and clarity, lacking low end response, etc. The subs XY in the middle by themselves sound quite horrible tbh. The main thing I wanted to test here is if the subs XY in the center added anything of value. When the 4 are mixed down they add quite a nice low end and provide some depth. The sum is definitely greater than the parts. I will post the raw and processed files later today. I ended up with a heavy hyper mix, about 75% with just enough of the subs to give some low end presence and space. Quite nice. Look forward to trying this in a less than ideal room to see how it holds up.
Also because I only have one set of DPA-A Bodies, I have to choose between hypers or card caps with the 2015 being a separate stand alone pair. So it needs to be some combo of subs and then either hypers or cards which is why I went hypers outside, subs inside.
Edit: Updated with links to the raw and matrixed files
https://drive.google.com/drive/folders/1dIvKOUiE_3DJlB0iU5x5VKlrHiRGyjsm?usp=drive_link
I don't have much to add on the technical front but did want to share that I think this tape sounds awesome - well done!!
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Never got around to hitting post yesterday on the message below before getting into the X/Y Mid/Side stuff today..
I finally got a chance to listen to FOCKER's recording and to Rock's first recording linked above Monday night.. but still need to go back and revisit Rock's second link to compare the two.
FOCKER, sounds good here. Really like the sound of those DPAs doing their thing. I mostly concentrated on Tangled Up in Blue from set 2, but very much look forward to listening to the whole thing casually at some point. Listening critically for what might make it even better, based in part on what I've found each pair tends to contribute best to the whole, along with the expectations I've developed for my own recordings, I do think it could work even better with the pairs swapped - 4015's on the outside and 4018's in the center coincident position. Sounds like the room and recording position would easily support doing that - and those are the only reasons not to in my way of thinking, unless there is some practical mic-mounting/setup issue that make that less attractive.
I expect the change will make the low frequency content more spacious feeling and involving, the overall sense of 3-dimensionality deeper/wider, audience reaction a bit more wrap around and diffusely distributed (all that due to moving the subcards out in the spaced position) while pulling a bit more transient detail and presence into the center, and with sharper imaging cues across the middle from moving the tighter-pattern supercards into the X/Y center position. A bit more focused while also sounding more dimensional. Not a huge difference, these are subtle things. Its hard to describe in words, but I really like hearing the sound of the instrumentation sort of blooming from a tightly focused center out toward the sides as it seemingly flows from the stage out into the room, and the room and audience stuff sounding very dimensionally "out there" beyond that. I think using the more directional pair which has less bass extension but sharper imaging in the center and the more lush, open-sounding pair in the spaced position helps to achieve that.
If I weren't critiquing in this way and just came across this recording I'd put all those thoughts out of mind and just enjoy it! Sounds great as it is and thanks again for sharing it here. I think you get the award for the strongest initial OMT recordings I've heard so far!
Rock, I also enjoyed your Eggy recording (first link). Still need to listen to the second mix and compare. This one took a bit more EQ for me to get where I wanted it (VLC built-in graphic EQ) ending up with a broad presence boost curve with a pretty sharp notch right in the middle of it (6kHz slider IIRC) and carefully compensated with a just a touch of additional boost to either side of it carefully dialed in. Vocals were overly distant sounding otherwise, but it was tricky to get the needed articulation there while not making the other content sharing that region overly strident. A pretty funky not smooth correction curve but it out worked well once I got it set. Other than that I think I'd prefer the spaced directional pair a bit closer in to the center with a bit more angle between them. Speculating a bit though. That's based in that thing about a nice tight, clear center blooming out the sides again.. keeping it cohesive while the additional channels adding layers of complexity. Will compare with your second link when I get a chance. Maybe tonight..
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One observation I made about both these recordings is that it really helped to download and asses one of the lossless files rather than trying to assess the streaming data-compressed version. I don't always find that to be as important. I wonder if the generally more well decorrelated audience ambience and reverberance has something to do with that, as that content tends to be more difficult to data-compress without artifacts. Similarly I notice that the FLACs of my 6' spaced omni pair are always somewhat larger than the FLACs of my near-spaced and coincident pairs from the same array. Which I assume is because there is less phase-correlation in the wide spaced omnis than the other pairs.
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^^^^^^^^^^^^^^
1] The streaming quality, esp on LMA is definitely not best to judge by, thanks for DL'ing them.
2] The Eggy vocals were distant live. We spoke about it later, sort of odd as we know that room.
3] The second mix is pretty different from mix one to my ears.
Thanks for the comments and listen. +T
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Vocals are all to often a sort of awkward step-child in the happy family of live sound!
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My recording of Trey from Tuesday was omt4ish. 4018as out wide, pointing at the outside of the stack, 4015gs DINa in the middle, on a single wide bar. I mixed the 4018s -6db down from the 4015s
https://archive.org/details/ta-20250401_202504
I also uploaded the separate 4015gs and 4018 tracks
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I don't have much to add on the technical front but did want to share that I think this tape sounds awesome - well done!!
Many thanks!
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FOCKER, sounds good here. Really like the sound of those DPAs doing their thing. I mostly concentrated on Tangled Up in Blue from set 2, but very much look forward to listening to the whole thing casually at some point. Listening critically for what might make it even better, based in part on what I've found each pair tends to contribute best to the whole, along with the expectations I've developed for my own recordings, I do think it could work even better with the pairs swapped - 4015's on the outside and 4018's in the center coincident position. Sounds like the room and recording position would easily support doing that - and those are the only reasons not to in my way of thinking, unless there is some practical mic-mounting/setup issue that make that less attractive.
I expect the change will make the low frequency content more spacious feeling and involving, the overall sense of 3-dimensionality deeper/wider, audience reaction a bit more wrap around and diffusely distributed (all that due to moving the subcards out in the spaced position) while pulling a bit more transient detail and presence into the center, and with sharper imaging cues across the middle from moving the tighter-pattern supercards into the X/Y center position. A bit more focused while also sounding more dimensional. Not a huge difference, these are subtle things. Its hard to describe in words, but I really like hearing the sound of the instrumentation sort of blooming from a tightly focused center out toward the sides as it seemingly flows from the stage out into the room, and the room and audience stuff sounding very dimensionally "out there" beyond that. I think using the more directional pair which has less bass extension but sharper imaging in the center and the more lush, open-sounding pair in the spaced position helps to achieve that.
If I weren't critiquing in this way and just came across this recording I'd put all those thoughts out of mind and just enjoy it! Sounds great as it is and thanks again for sharing it here. I think you get the award for the strongest initial OMT recordings I've heard so far!
Many thanks here as well!
So this is not what I would typically run in this venue. It was more about m just trying something new to see how it felt / worked, etc. In general i prefer the sound of subacards to just about any other pattern and would prefer for that to be the centerpiece, so to speak. However, they tend to lack some detail which is what attracted me to trying out these OT approaches. I would generally used thw 2015s as the primary pair, with the hypers filling in as needed. The only exception being when I'm truly in a bad room or arena, etc. Getting ahead of that I wanted to kick the tires on different setups where the hypers were the main focus and figure out what works best given the options I have. To that end, I think the result was positive in giving me more information.
Big props to you for all you've done to fine tune these ideas and approaches. Ive had more fun running these setups than I have had taping in quite some time. I will say this, you do tend to get some odd looks while setting up because it is definitely out of the norm within this community. I think once you start talking about it with other tapers, it starts to make more sense. I try to convey it as a variation of mid/side for those who inquire.
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Thanks for the kind words!
Glad you're enjoying using some of these oddball arrangement ideas, and fully with you on the love of the subcard sound. It's my favorite pattern for a single stereo pair when the situation allows for it. I've written about this in these threads before but it bears repeating.. Even though I'm not using subcards in my setup currently, if you consider the combination of all the microphones together in it - their angles, patterns and levels in the resulting mix - their collective sum forms what is essentially something like a subcardioid sensitivity pattern facing the stage. Tweaking levels, angles, and which mics are used where then modifies that collective pattern one way or another as needed. In more difficult rooms where the mics are necessarily more forward focused, that combined collective pattern becomes more cardioid like. In great rooms and outdoor amphitheaters it trends more omnidirectional, yet still essentially subcardioid with an important degree of forward-bias toward directed toward the stage to get a sufficient sense of proximity, clean details, and clear vocals. The only times I've ended up with a fully omnidirectional sensitivity in all directions is in the center of a circle of musicians and with nature or other ambient recordings.
If you do try swapping the positions of the 4015s and 4018s let me know what you think of the sound of that in comparison to the other way around. Your comment about the 4015's working really well in the primary role but potentially benefitting from a bit of extra detail from the 4018's dovetails perfectly with that.
Totally hear you on the odd looks! Funny how some folks are very curious while others shake their heads WTF when they see these arrays getting setup and used, even more so with my inclusion of a pair that's quite obviously facing backwards. Used to be a taper who regularly attended fests at the Spirit of the Suwannee for a few of years who actually got angry with me a couple times for pointing mics in "all the wrong directions" and was not in the least interested in hearing why I might be doing that, stomping off when I didn't immediately acquiesce to using a standard DIN arrangement. Most tapers aware of my proclivity toward these things enjoy someone doing something different even if they have no interest in going there. Fun talking with sound guys about it who often walk over with questions. Some get what I'm doing right away, while others have commented that they're working so hard to deal with sound bouncing around from directions other than the stage while I'm there trying to figure out the best way to capture the same stuff. I reassure them that I would be unable to create such a successful "you are there" teleportation-time-machine like listening experience if it were not for their excellent work in managing the sound as heard by the audience in the room, which means the sound arriving from all directions including the stage and PA. So much of the live magic occurs out in the room once the sound has left the stage and PA. That always makes them smile and may persuade a few, while at least getting the others who may still consider this crazy feeling good about what they are doing!
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The soundmen who have spoken with me or asked about the arrays genuinely seem interested in the why and then they typically get it. I have been asked by two soundmen to share the recording with them so they could check out the difference compared to their SBD mixes.
Most attendees have only ever asked about the why of pointing mics backward, which I do not do much anymore indoors.
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My recording of Trey from Tuesday was omt4ish. 4018as out wide, pointing at the outside of the stack, 4015gs DINa in the middle, on a single wide bar. I mixed the 4018s -6db down from the 4015s
https://archive.org/details/ta-20250401_202504
I also uploaded the separate 4015gs and 4018 tracks
Great stuff!!!
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OMT sighting in the wild yesterday.
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Craig, whose rig? Has to be someone in this thread. lol
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Craig, whose rig? Has to be someone in this thread. lol
Lee's OMT8 and my OMT4 at Southland Bluegrass Fest.
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Great to see you there Craig!
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I mentioned reworking the rig pictured above a month back before a previous fest - Amp Jam #1 on Suwannee - which in part included eliminating all gaffer tape, now used only for repairs and other temporary applications. Woo!
A couple important improvements were made regarding how the Movo windscreens containing the miniature DPA 4097 supercardioids are mounted and sealed to prevent wind entry from the rear. Below are a few photos of some details of that, followed by a couple taken during the opening set of the fest including one from up front looking back toward the section.
The DPA 4097 supercardioid is the same diameter as the 4060/1 omnis, but are about 2" long and require more robust wind protection. Movos work well for that but are sized to fit a typical 19 or 20mm diameter SDC, so I fit the mics to the windscreens using little foam cylinders pulled from a cheap dollar-store hair curler set. They're open cell foam, the right length and diameter, and feature a hole through the center which is perfectly sized to fit the microphone. Indoors those alone are usually sufficient, but years ago I decided to just run the bigger windscreens everywhere, simply because switching to them when necessary was somewhat of a PITA, and because I ended up using the windscreens themselves as the mic-mounts, which additionally provides a limited amount of shock isolation that's fully sufficient for my needs. I've posted about those little foam cylinders in these threads in the past as I used them with the big ass Shure's before moving to the Movos.
One problem is that the hole in the rubber cuff of the Movo is too large to seal around the small diameter gooseneck of the microphone. In the past I've used gaffer tape to seal that, but it doesn't adhere well to the cuff rubber, so it took a few strips to cover the entire back of the Movo which wrapped around the edge of the cuff secured by an additional narrow strip of gaffer tape wrapped around the cuff like a belt. Not pretty or neat but it worked. That's now all eliminated, replaced by by a neoprene disk that fits tightly around the mic-gooseneck and is snugged up tightly against the back of the cuff. I cut the neoprene disks out of an old large mouse-pad. The two on the rear-facing pair features an additional small hole through the disk which is offset slightly from center. That accommodates the support bar which is about the same diameter as the gooseneck and supports the windscreen by wedging between the Movo and the hair curler foam insert.
The Movos used on the forward-facing near-spaced (~24") pair are now attached directly to the horizontal bar via a stainless-steel hose clamp around the Movo cuff (clamp band is covered in black heat-shrink) and a black zip-tie. The zip-tie is routed in a figure-8 pattern around the bar and the adjustable-screw part of the clamp, an arrangement which secures the Movo tightly to the bar while still allowing sufficient rotational freedom in the horizontal plane to angle that pair mics +/-45 degrees away from center as I typically do, or narrow them to PAS when necessary.
Note- In the second to last photo looking up at the mic array from below, the stage is located below bottom edge of the photo.
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Also worked up revised rain protection. Excluding the wide-spaced omnis, the central near-spaced mic section of my OMT8 array is to wide to be protected by what I consider a reasonable sized single umbrella, and multiple small umbrellas would be a real PITA. Instead I decided to make a set of small bonnet hoods, one of which can be quickly attached to each mic. I put together the elements of this system a couple years back but haven't needed it so never got around to actually using it or even fully setting it up until now.
The idea is to basically emulate the "duck back" device which attaches to the top of a wind-blimp providing rain protection. My simple variation on it consists of a piece of flexible plastic filter mat with umbrella fabric glued to one side. The filter material provides the structure and breaks up and disperses rain drop energy. The umbrella fabric on the underside affixed to it with spray-glue provides a water-tight barrier. In use, that flat disk is formed into a taco-shaped bonnet hood, secured directly to the windscreen with a zip tie - two zips used on the shotgun mic. The zip tie isn't made overly tight, just tight enough to secure it from wind. The hood simply slips in and out under the zip tie - both get reused. Rain trickles through and drips off the edges of the bonnet, and the locking part of the zip tie is oriented downward forming a drip point. The whole system accommodating all 7 microphone positions fits into a gallon sized zip lock bag.
First photos of just the center stereo-shotgun. These were taken last weekend while getting ready for last Sunday's fest. No rain threat for that one so the new rain protection system stayed in the car. I just set it up in the driveway the day prior to take these photos to share here.
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I took the full system with me to the fest but only deployed it on the center AT stereo shotgun when rain threatened the final day, as I needed to get running quickly and that's the only mic in the array which I'm not certain can handle getting wet and recover gracefully. So the photos of it in use below at the fest show only the center one on the shotgun mic. Plan was to deploy on all other mics at the conclusion of the set if necessary. Fortunately the rain threat passed.
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Here's the complete setup fully deployed, with detail shots of one of the smaller sized Movos which is the size typically used by most tapers so may be suitable for other folks here. Note the even smaller ones out on on the 4061s at the far ends, however they weigh down the telescopic antennas a bit to much for my liking and create extra windage out there, so not sure I'd keep the omnis fully extended with those in use.
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I dig the hose clamp idea. I wonder if some narrow cam straps could replace the zip ties for security and longevity? https://rollercam.com/products/0-75-straight-end
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Great ideas GB. Are the neoprene disks glued to the back of the movo or do you just press them against the movo to get a secure fit?
Like the rain protection idea too.
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Yes, +T for the rain protection concept and documenting/sharing your idea. I dig it.
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Thanks!
Along with the relative ease of set up I really like the reduced windage and visual profile of the rain system compared to an umbrella. Will see how well it works once it really rains. May break out the hose next weekend. Not mentioned above is that I applied a Never-Wet hydrophobic treatment to both sides of the bonnets so water beads off quickly. Not sure if that's really needed but thinking it may help keep the filter material from holding water due to surface tension and getting heavy. I may just just forgo using the tiny bonnets on the omnis as long as the sound doesn't change as their small windscreens get saturated. In previous tests the hydrophobic treatment applied directly to the windscreens rejected moisture and indirect water spray, but still allowed direct droplet hits penetrate, which is what lead me to putting the bonnets on top.
A very small cam strap attaching the hose-clamps to the tubing could work but would need to be just 1/4" wide, and the simple zip tie connection is working very well. I keep extras in the bag, but doubt I'll need them as replacements. I did need to reinforce the section of telescopic tubing that the tie wraps around by sliding a length of 3/8" diameter stainless steel hydraulic piping with a significantly heavier wall thickness over it in order to prevent the thin-walled telescopic tube from being crushed/bent when the zip tie is cinched down tight. It's a relatively small (normal sized?) 1/4" wide zip tie that once in place just remains locked down as tight as I could get it with a pair of pliers and doesn't require further readjustment. The cool part is how the fig-8 wrapping holds the curved surface of the hose-clamp's adjustable screw housing against the telescopic tube in such a way that the length of the tie needn't change when rotating the mic/windscreen assembly vertically and horizontally within a useful range. Heat-shrink applied over both tubing and hose-clamp to form a nice scuff-resistant matt black surface that also provides the right amount of friction to hold the desired angle. I intended to secondarily incorporate a way of sliding the connection along the bar, so that the spacing between the pair can be altered along with angle. Didn't get that far - the friction of the heat shrink which is needed to keep the forward cantilevered windscreen from drooping vertically doesn't also allow for sliding along the length the tube. Practically, arranging for that further improvement may require some sort of little spring clamp in place of the zip-tie, perhaps a 3d printed hinge/clamp thing - squeeze to adjust and when released it grabs the tube and locks in place.
Currently the neoprene disks are simply pressed against the back of the Movos (rubber to rubber) and held in place by friction on the gooseneck and or support tube. The disks don't lay perfectly flat, so I oriented them as needed to achieve the best seal. The original idea was to try and work the disk though the hole in the back of the Movo so the disc is tightly sandwiched between the rubber cuff and foam, but that proved too difficult to do with the mic already in place. Also tried carefully inserting the mic (don't want to crush the tiny interference tube grid) into the windscreen after curler foam and disk had been installed , but its impossible to keep the small hole though the curler foam insert lined up with the small hole in the disk, which inevitably results in the curler foam getting mashed inside as the mic is inserted rather than the mic sliding into it. So far the simple press-against fit has worked better and more consistently than gaffer tape. If I do get wind leakage I'll probably look into sealing it using double-stick tape or a smear of sealant between the two depending on what sticks to the rubber.
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My recording of Trey from Tuesday was omt4ish. 4018as out wide, pointing at the outside of the stack, 4015gs DINa in the middle, on a single wide bar. I mixed the 4018s -6db down from the 4015s
https://archive.org/details/ta-20250401_202504
I also uploaded the separate 4015gs and 4018 tracks
Enjoyed listening to this right nice sounding recording last night! Very cool to be able to compare the mix and separate mic pairs, EQing each to be as close as possible.. and after doing that it was encouraging to find I still preferred your mix over either pair on its own. Great performance, room, audience, and recording. Stars aligned on that one.
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I always want to share each source separately to give back because that’s a huge part of how I learned.
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^ Thanks for that. Hard for me to imagine a signal path I'd prefer over that one!
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My next step is adding the ad8+ so I can add the senn ambeo vr to the mix.
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OMT’ers,
I recently got 2 really clean pulls at The Brothers MSG show. I’m super happy with the audio they are probably 2 of my best OMT pulls I deviated a little bit from the OMT6 in Gutbucket’s OMT guide and ran the following:
Channels 1 & 2: B9 Audio C5F 14" Spread pointed straight ahead> nbob actives > baby nbox > 3.5 mm TRRS stereo breakout to dual left / right XLR male >
Channels 3 & 4: AT3031 7" spread PAS>
Channels 5 & 6: AKG c414 XLII Hypercardioid Mid + Figure 8 Side set 9" in front of other 2 pairs
Zoom f6 32 Bit Float
The results:
2025-04-15: https://archive.org/details/brothers-2025-04-15t-17 (https://archive.org/details/brothers-2025-04-15t-17) (8’ high in soundboard cage)
2025-04-16: https://archive.org/details/thebrothers2025-04-16t24/thebrothers2025-04-16t05.flac (https://archive.org/details/thebrothers2025-04-16t24/thebrothers2025-04-16t05.flac) 14’ high top of soundboard cage (significantly higher than night prior where I was going from soundboard inner area floor)
Slight EQ on both nights in post.
I really love how these sound, I find them a little bit muddier than the room was last night. Is there anything I can do mix wise to boost the clarity and damper the mud a little bit? I really have no clue what I’m doing with mid/side I’ve run this arrangement a few times now and feel I’m improving on my mixes each time but could benefit from some guidance for sure.
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Listen to each source separately. Adjust the mid side until it’s got the clarity you want for the base of the mix.
Create a stereo track from each source and save them separately. Then open a new session with all 3 stereo mixes and adjust the levels on each until you think it sounds best.
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Listen to each source separately. Adjust the mid side until it’s got the clarity you want for the base of the mix.
Create a stereo track from each source and save them separately. Then open a new session with all 3 stereo mixes and adjust the levels on each until you think it sounds best.
This is super interesting way of tackling it I feel like I’ve been taking the opposite approach. I’ve been leaving my mid as is, bringing my side down low and then adding in the hypers and then the cards. I build houses so I was thinking of it in that regard; Foundation > structure/ guts > finishes.
I’m gonna take a stab at it the way you mentioned, maybe I’ll like my results better. Prefab home style
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Looking forward to hearing that Brothers!
Interesting to me that a number of the recent recordings posted here have arranged things with the more directional patterns in the wider-spaced positions.
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Mixing OMT-
It's always insightful for me to build the mix a few different ways. After I initially home in on a rough mix I like to break it down and re-build it a few different ways from different starting points and see how differently each ends up, then go back and forth to compare and determine what's best and not best about each. That helps me determine where the ultimate point of convergence between each of them lies, which tends to be the best overall choice in the end. Determining exactly what that might be and and the best way of getting there is the thing.
Note that most of the time I'm not actually saving these mixes to compare them, although I do that sometimes. I'm usually just quickly altering levels, which channels are active, and maybe a few other settings to go from one to another while playing with further tweaks as I do, to home in on the best collective target.
That process of building up the mix in different ways has helped me develop a good understanding of what each mic-pair contributes best and how the different mic channels interact with each other. Working up the mix in different ways leads to different end results, each of which sound good in a somewhat different way. It's interesting to see how much the range of "good sounding alternate mixes" varies for any one particular recording, but more fundamentally each represents a different potential focus for the final mix - different examples of where the mix might be legitimately be taken. That allows me to choose between them, or more frequently to use them as reference points in working further toward a improved mix that seeks to balance each of those attributes in a superior mix that I likely would not have arrived at if I'd not compared them in that way. In other words, I suggest this method not only as a good approach in general for mixing these recordings (and understanding how they work on a deeper level), but also as the only way I've found I'm consistency able to produce a mix that sounds good to me over time and translates well to other listening situations. Just listening and winging a mix can produce satisfying results, but never works out as well in terms of consistency and translation for me.
The initial starting point is adjusting each pair for good stereo balance on its own. Working up a rough initial mix I tend to start with the wide pair (omnis or whatever is widest) as the foundation, then add just the center mono Mid to that, looking for a good L/C/R stereo balance. The Mid is acting "in support of" the omnis, adding clarity, articulation and a solid center. I'll then bring up the Side channel while listening primarily to the stereo spatial aspects. That's OMT4 built atop an omni foundation. I'll then start over and do it the opposite way, starting with the mono Mid and adding Side until I get a good sounding stereo image, then bring up the omnis or wider pair in support. That's OMT4 built atop the foundation of a Mid/Side center pair. Do the different approaches end up at exactly the same endpoint or are they different? If different, what do I prefer about each one? After some more listening and tweaking, can I reach a compromise point between the two that's better than either? Does simply hearing the second option change my preference for what I previously valued in the first one? When there are numerous good sounding options, that kind of process of gaining insight into which actually is best becomes increasingly valuable.
It gets very interesting with higher channel count OMT setups where there are 3 or 4 separate pairs and lots of mix permutations. Some combinations of mic channels are extremely unlikely to be used on their own as a final mix, yet I still find it best to arrange the mix such that: 1) any combination of channels to be used makes for an improvement over that pair or channel as heard in isolation, 2) the inclusion of additional mic channels or pairs to the mix must always makes the mix better not worse, and 3) the mix suffers from the removal of any one channel or pair. Confirming that entails a lot of channel muting/unmuting checks. For example, when mixing my OMT8 recordings I listen to things like just the 3-channel balance of the mono center Mid + rear facing pair, even though I'd never actually use that combination alone as a final mix. Even though that's an odd combination by itself, the final mix works out better when just that part in isolation is appropriately balanced with all other channels are muted. Similarly I also spend time listening to and working on the balance of just the near-spaced pair + the center Mid, which on their own form a 3 channel L/C/R mic triplet.. What happens when the Side channel is added or taken away again from that? Does it also work with just the 5 near-spaced supercards on their own? Those 5 + Side channel? Do the balances need to be altered slightly for all these combinations to work? I like getting even the oddest channel combinations to work correctly this way. For instance, does adding nothing other than the rear facing directional pair to the omnis make for an improvement over just the omnis alone? If it doesn't it may be an indication that I'm using a bit too much of the rear-facing pair in the mix. If I'm unable to adjust levels such that the inclusion of any particular pair or channel doesn't make everything else better than it was without that addition, that pair or channel probably shouldn't be in the mix.
After playing around muting/soloing the various channel combinations and adjusting levels to confirm that all of them make sense as various isolated groups yet the combination of them works best of all, the final adjustment for me is going back and tweaking the level of Side channel from the center pair. When there are multiple mic pairs in the mix there are many sources contributing stereo difference signal. How much Side channel I use in the mix becomes as much about the perception of "openness and a sense of 3d space" as it is about Mid/Side stereo image placement and width in the traditional sense.
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^ Note to anyone who may have read the post above already. I edited it significantly this afternoon a few times- some corrective and for clarity, others to flesh it out a bit more.
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What recorder are you using these days? When you first started this adventure, it was the Edirol r-09!!
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^Me?
Open-taping: Zoom F8 (v1) in the OMT8 rig for the past 7-8 years or so. Previously DR-680 (OMT6), before that R-44 or DR2d (OMT4), prior to that a couple unsync'd R-09's.
Stealth: Deity PR2. Preferred OMT4 stealth arrangement currently out of operation (DR2d).
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I have one more coming for you guys later tonight. Eggy at Brooklyn Bowl on Friday night. Ran OMT4 with 2015 2' in AB. This is a slight variation on previous tries with no angle on the subcards in AB - previously nhave run them at 90 degrees. We were only about 20' from the right stack, felt like a good opportunity to give this a try. And then the 4018s XY in the center at 90. Sounds good, very happy with the results (again)
BTW, Eggy is damn good. Super impressed by those guys.
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Apologies in advance for parts of this that are duplicated from a post in Acoustic Recording Techniques, but I thought this may be of interest to this group as well.
Earlier this month I ran a more complex array for a non-PA amplified show, stage lip.
The mics used were:
1) CMC122 @+/-55°, 24"
2) CMC641 @+/-45°, XY - ~2" forward of other mics.
3) DPA 4060 @24" taped to stage
Please see pics below for context of both the band and the mic set up.
The intent was to have options of two different OMT 4 type set ups, using either the subcards or omnis for the outboard pair, with the hypers XY in the centre. I didn't end up liking the mix of any of the mics with the omnis, which may be due to the limited spacing (it was a tiny stage and logistically challenging to get more than 24" spread).
I ended up with an OMT4 ish set up using the 122 and 641 with samples posted here, with which I was very happy.
https://samply.app/p/FqcMuOjiLELXeu9AHMPo (https://samply.app/p/FqcMuOjiLELXeu9AHMPo)
Today, I went back and created samples of the same 2 songs with just the omnis, located directly below the 122s, as a reference, to highlight the advantages of the OMT4 set up.
https://samply.app/p/0HRNqc0B2hnWvbHkMzEE (https://samply.app/p/0HRNqc0B2hnWvbHkMzEE)
I realize this is not a direct comparison but it highlights some of the trade offs between the two mixes as the horns are a bit more distant in the recording that does not include the OMNIs but the sense of space, and refinement of the treble (lack of harshness) is better with the open card, hyper array.
I find both the difference in frequency response, and sense of space, an interesting contract between the two and I strongly prefer the separation in the OMT set up.
The processing that I would highlight as being relevant would be:
1) I increased the level on the right side of all three stereo pairs slightly prior to mixing. Unlike with a PA recording, this was an attempt to bring the trumpet more in mix as he moved around quite a bit and was frequently further from the mics. This was at the expense of increasing the guitar beyond my perception of the mix in the room and may have the effect of pulling the objects LOC further right in the resulting mix. Not necessarily a bad thing given the layout of the instruments onstage.
2) No EQ adjustment was made to the 122s or 641s, however, I did try to adjust for the DPA bump at 12khz with a reduction of 2.5db at 7.96khz and 4db at 12.6khz. I'm still learning with EQ so wanted to minimize any adjustments, however, I did find the treble harsh likely made worse by the reflections due to the lack of absorbing materials on and around the stage.
3) Samples were RMS normalized (for the set, not the individual songs) to make comparisons easier.
I have samples from a binaural(ish) recording of the same band the previous month below (4060s mounted to glassed at temple>R07). I thought this provided a solid representation of space, with reduced treble "harshness", possibly due to my head absorbing reflections. No EQ was applied to this recording and it has not been normalized to the same levels but sharing in case it is helpful in providing context.
https://samply.app/p/Ga5WbtzNargjM4rqsvTD (https://samply.app/p/Ga5WbtzNargjM4rqsvTD)
If you decide to give the samples a listen, and you would like to stream them for convenience, please consider going to audio options at the bottom of the page and selecting lossless.
I may, per GB's suggestion, consider placing the DPAs under the stage lip to capture the audience turning this into more of a OMT6(?) set up next time. That would allow me to bring in the audience a little more at key spots as well as increasing the stage talk as the front of the PA was behind the mics resulting in the banter sounding a bit more distant than ideal.
This is a really interesting thread and thanks to all who have shared ideas and recordings here. It's been a great learning experience!
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thelonious,
I dig your set up and the mounts for the mics. I own a triple bar and find it very useful.
Thanks for sharing
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Pink Talking Fish at Ardmore Music Hall
OMT4 4018VLs spread 2' at 30 degrees + 2015s XY in the center. This matrix is roughly 80% hypers and 20% subcards
https://drive.google.com/drive/folders/1xf8xruOw_aDOLRA3w9qZQ8lUA8ib6I9Y?usp=drive_link
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Earlier this month I ran a more complex array for a non-PA amplified show, stage lip.
The mics used were:
1) CMC122 @+/-55°, 24"
2) CMC641 @+/-45°, XY - ~2" forward of other mics.
3) DPA 4060 @24" taped to stage
Would certainly be pleased with either recording but I enjoyed the omni sample the most. More even and natural across the board, easy to listen to and take in the entire band at once. Stage lip recordings when there's no vocalist are great.
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thelonious,
I dig your set up and the mounts for the mics. I own a triple bar and find it very useful.
Thanks for sharing
Thanks Rock. First time using this particular set up and eas very happy with it.Earlier this month I ran a more complex array for a non-PA amplified show, stage lip.
The mics used were:
1) CMC122 @+/-55°, 24"
2) CMC641 @+/-45°, XY - ~2" forward of other mics.
3) DPA 4060 @24" taped to stage
Would certainly be pleased with either recording but I enjoyed the omni sample the most. More even and natural across the board, easy to listen to and take in the entire band at once. Stage lip recordings when there's no vocalist are great.
I can see the case for either recording based on playback system and preference. The omnis certainly win in the time to set up category! I agree the Omni’s sound more even across instruments while the array has more separation between instruments.
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Checking in as I just got back to town. Will give a listen and comment when I can but may not be until next week as I'm only here for a few days.
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Sharing my OMT4 of Spafford from Friday night. First time running it outdoors. This is mainly the wide cards with the supercards adding in some detail and punchiness that was lacking from the widecards. Turned out quite nice.
DPA 2015 + DPA 4018VL -> Sonosax SX-R4
2015 were PAS about 2' spread, 4018VLs XY at 90 in the middle. One change from previous setups is I have all the mics lined up on the same plane vs having the "main" pair 7-8 inches forward. I cant tell if this is tighter due to the mic placement in a plane or the fact it was outdoor and no reverberant noise to deal with, or both. I have some indoor shows to play with this setup more. It 's easier for me to place them all in a line now with some changes to my setup making it more streamlined on the same bar.
FWIW I will post pics later but Scott at SRS Recordings made me a 2' bar that has multiple clips that slide on at various degrees so I have the flexibility to run any standard config plus all the OMT stuff from one bar. Very convenient and light.
For those new to Spafford I'd recommend Neutrino and then the jam out of Steve Miller's Swingtown cover as good examples of where they can go jamwise. This was a "Concert Under the Stars" series here so fairly cookie-cutter playing from them imo, still fun. Neutrino starts to show Spafford's style and sound around the 5:30 mark on.
https://drive.google.com/drive/folders/1YDPm-VHW5p9b8r4SDDbMvsckVd1w9NrY?usp=sharing
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Here is a link to the bar Scott Shepard made for me. I’ve got clips that give me a range of angles and can slide those clips to any distance up to 2’. And put some tape on there to keep the clips locked in tight but it works really well. Not on the cheap side but replaces all the other bars I have.
https://drive.google.com/file/d/1YXtmfcYxwkyu-sovpwhQ95MmhsQWtFz_/view?usp=drivesdk
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I haven’t heard the recording from Friday yet but look forward to doing so soon.
That bar looks awesome and would greatly simplify my set up. I can’t tell what holds the mics at angle from the picture. Do they hold with sufficient force to keep the mics on desired axis?
Do you know what Scott called the bar? I looked on eBay and didn’t find it on first pass.
Thank you for sharing this!
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https://archive.org/details/nmas2025-06-15.akgck61c34dpa4061
North Mississippi Allstars
2025-06-15
Sacred Heart University Community Theater
Fairfield CT
This is, to my ears, the finest OMT recording we have made to date.
Here is the mics and mix notes:
source:MDAUD
ch1|2: DPA 4061 omnis spread 243 cm (8 feet apart; 4 feet from center) ++ > Tascam DR 680|SD
ch3|4: AKG ck61 cardioid PAS|nobob|naiaint PFA's > Grace Lunatec V2 > Tascam DR 680|SD
ch5|6: AKG c34 cardioid XY 70' > Sonosax M2D2 > Tascam DR 680|SD
mix Info: C34 0dB, ck61 -5 dB, DPA4061 -5 dB relative to zero
++ The DPA 4061 were placed IN FRONT and against the 2 foot tall glass safety barrier on the balcony.
There was this 2 foot tall glass barrier on top of the balcony counter. A nice 4 foot wide counter was split in half THEN security asked not to set anything on the ledge!
So, we used a stand and I ran the cords of the DPA's through small slits between the glass pieces and taped the mics to the glass for a boundary layer effect.
In my opinion the SQ of the DPA's is enhanced by the mounting to the glass, more high end and "richer" bass tone.
I recall the OADE brothers doing things like that on outdoor shows in 1984 and 1985. Once they used a giant, 3-4 foot wide plexiglass on a hinge behind their mics. After that I recall smaller plexiglass circles with the mics mounted in front. (but that may have been Jaime Poris' crew, or daspy's crew)
Either way, if some of you get a chance to check it, let me know if it seems like a good OMT6 outcome
{the pic shows the glass barrier, but NOT the DPA's}
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Here’s a close up of the 45* clips maybe this will help. These two give me the XY in the center
https://drive.google.com/file/d/1-qG3OFtebSbBn7wBU9rT7B36M1ZSbhlp/view?usp=drivesdk
This is not on his ebay site, but if you email him he can price it out for you. It was actually a bar he uses and he recommended to me. I wanted one bar with the flexibility to run mics from any position
I do use gaffers tape on the bar to give the clips a tighter grip to the bar and then when the mics are up I give enough slack on the cables and the tape them up to provide support. Works like a charm.
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Here’s a close up of the 45* clips maybe this will help. These two give me the XY in the center
https://drive.google.com/file/d/1-qG3OFtebSbBn7wBU9rT7B36M1ZSbhlp/view?usp=drivesdk
This is not on his ebay site, but if you email him he can price it out for you. It was actually a bar he uses and he recommended to me. I wanted one bar with the flexibility to run mics from any position
I do use gaffers tape on the bar to give the clips a tighter grip to the bar and then when the mics are up I give enough slack on the cables and the tape them up to provide support. Works like a charm.
Cool looking bar. What mm is it? What is the mount point in the center (which brand clip is it, OR is it made by Scott?)
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Here’s a close up of the 45* clips maybe this will help. These two give me the XY in the center
https://drive.google.com/file/d/1-qG3OFtebSbBn7wBU9rT7B36M1ZSbhlp/view?usp=drivesdk
This is not on his ebay site, but if you email him he can price it out for you. It was actually a bar he uses and he recommended to me. I wanted one bar with the flexibility to run mics from any position
I do use gaffers tape on the bar to give the clips a tighter grip to the bar and then when the mics are up I give enough slack on the cables and the tape them up to provide support. Works like a charm.
Cool looking bar. What mm is it? What is the mount point in the center (which brand clip is it, OR is it made by Scott?)
Looks like a Rycote Duo-Lyre (https://www.bhphotovideo.com/c/product/1054451-REG/rycote_40138_model_duo_lyre_68_19_34.html) on top of Scott's Rycote lyre mount (https://www.ebay.com/itm/135507710900?_skw=rycote&itmmeta=01JYES4Q9KXMBSRP5TEEZQVQM1&hash=item1f8ce393b4:g:ZVYAAOSw9NhnjYk7)
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Here’s a close up of the 45* clips maybe this will help. These two give me the XY in the center
https://drive.google.com/file/d/1-qG3OFtebSbBn7wBU9rT7B36M1ZSbhlp/view?usp=drivesdk
This is not on his ebay site, but if you email him he can price it out for you. It was actually a bar he uses and he recommended to me. I wanted one bar with the flexibility to run mics from any position
I do use gaffers tape on the bar to give the clips a tighter grip to the bar and then when the mics are up I give enough slack on the cables and the tape them up to provide support. Works like a charm.
Cool looking bar. What mm is it? What is the mount point in the center (which brand clip is it, OR is it made by Scott?)
Looks like a Rycote Duo-Lyre (https://www.bhphotovideo.com/c/product/1054451-REG/rycote_40138_model_duo_lyre_68_19_34.html) on top of Scott's Rycote lyre mount (https://www.ebay.com/itm/135507710900?_skw=rycote&itmmeta=01JYES4Q9KXMBSRP5TEEZQVQM1&hash=item1f8ce393b4:g:ZVYAAOSw9NhnjYk7)
+T I'm looking at the two now. I have four Rycotes Dual Lyres with mounting bases I never use these days. hmmmmmmm
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Here’s a close up of the 45* clips maybe this will help. These two give me the XY in the center
https://drive.google.com/file/d/1-qG3OFtebSbBn7wBU9rT7B36M1ZSbhlp/view?usp=drivesdk
This is not on his ebay site, but if you email him he can price it out for you. It was actually a bar he uses and he recommended to me. I wanted one bar with the flexibility to run mics from any position
I do use gaffers tape on the bar to give the clips a tighter grip to the bar and then when the mics are up I give enough slack on the cables and the tape them up to provide support. Works like a charm.
Okay, so the clips are a fixed angle (45 degrees). That makes sense. Thanks again, this is a very practical set up and I appreciate your sharing. I have a couple of mic bars but the larger ones are really heaving for travel (particularly flying).
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Okay, so the clips are a fixed angle (45 degrees). That makes sense. Thanks again, this is a very practical set up and I appreciate your sharing. I have a couple of mic bars but the larger ones are really heaving for travel (particularly flying).
Ah yes, I should have been more clear. All of the clips are fixed angles, all I can do is slide them along the bar to adjust spacing
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Finally getting a chance to get back to this thread to find some very nice recordings and cool setups! Very encouraging!
I did some listening last night to catch up.. (Senn HD650 HD600 headphones)
@ Thelonious- Thanks for sharing that great write-up of your recent on-stage acoustic recordings with examples, and documenting it so nicely for the rest of us. Making those kinds of comparisons is so valuable in determining what works best and which way you want to go with it. I found myself liking both examples that you included links to for somewhat different reasons.. and desiring something which embodies the best qualities of both. The omnis alone sound very natural and easy to listen to which I very much like. I also enjoy the increased clarity and somewhat more direct sounding quality of the horns in that recording. Listening to the OMT4 recording I immediately notice the top quality of of the mics used. Nice smooth timbral balance. I can hear what you mention about the increased separation - loads of stereo width, distinct placement of sources and portrayal of enveloping ambience, which are all qualities I associate with the technique. I did find myself wanting the ambient / reverberant / room stereo qualities to have a bit more of the naturalness of the omnis, but that preference may be accentuated by my listening with headphones rather than speakers.
A few thoughts on possible improvements-
1) Curious if you tried the omnis + the center CMC641 @+/-45°, XY pair without the 22's. I assume you did, and would like to hear more of your thoughts on how that worked or didn't. My initial thought is that should improve on what I hear from the omnis alone. If you did and it didn't work, perhaps the omnis needed to be spaced more widely. Also curious if you tried including just a touch of the omnis in the otherwise straight OMT4 mix, or the other way around with just a touch of the 22's in a mix of the omnis and X/Y hypers? I suspect either of those may work better than a more equal-level combination of omnis and 22's since those two pairs were positioned rather close to each other by necessity which could cause some problems when mixing them together.
2) I suspect the omnis provided more direct clarity of the horns because when placed on the floor they essentially form an upward-facing hemispherical sensitivity pattern which more or less faces directly at the standing horn players. Options for increasing clarity and direct pickup of the horns in the OMT4 setup using more directional mics might be angling either the 22's or 41's more upward to get the standing horn players more on-axis. That entails a sort of balancing of the vertical angle between facing the drums and floor level sources with the mics angled lower, verses the and horns with the mics angled higher. Might angle both pairs upward by the same amount, or just one pair or the other, which can additionally helps by increasing the differentiation between the primary focus of each pair. One thing to be careful of in regard to the upward angling of mics is how that changes pickup of the drum kit. Increased upward angle is likely to make the cymbals louder/brighter. When on-stage the mics are close enough to the drums that a relatively small change in vertical angle can be significant.
3) In this situation I might angle the 22's more widely. Not because the OMT4 mix needs more imaging width (I don't think doing so would make the direct imaging content sound "wider"), but because that would make their contribution more similar to what omnis provide in terms of room / reverberant / ambient contribution. It shouldn't be problematic because the X/Y hypers are anchoring the center part of the image. Also, because the array is placed on-stage relatively close to the sources, angling that pair somewhat more widely will be generally less problematic than it can be when recording from farther away where it might increase pickup of audience and reflections of the side walls too much.
@ Focker, I'm really digging that Spafford recording! Very clean and tight, nice image distribution and overall feel. Fantastic on headphones last night - it was easy to put all the technical critique aspects out of mind and just enjoy it. What are your thoughts on inverting the arrangement for this one verses the way you had it setup for Pink Talking Fish? (This one using the 4017's for X/Y in the center and 4015s as the spaced pair)
@ Rocksuitcase, thanks always brother, really enjoyed listening to this one too! I did find myself wanting a bit more upfront clarity, but that's always a challenge when recording from in back, and had just come from that super clear Spafford recording. I scooped a bit of upper bass / lower midrange and that perceptually did the trick for me. Love the creative routing and mounting of the omnis and the ability to get the 8' wide. Nailed it.
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I ran my OMT8 rig onstage for a fantastic instrumental gig a couple weeks back. Artist is an astoundingly adept musician friend, and the band consisted of great local musicians, several of them music professors at nearby universities. I'm very fortunate to have been given access to archive a significant number of his local live performances over the past decade or so. I've a long standing, on-going promise to him not to distribute any of these recordings (that may sound ironic as I so rarely get around to doing so anyway - along with my renewed apologies for it). That said, if any of you ever find yourself in South Florida, hit me up and we'll don the headphones.
I will discuss and share some photos though. Venue this time was the Savor Theater formerly Cinema Paradiso, a small arts theater, primarily of cinema, which was a former church converted something like 30 years back with the installation of cinema-style inclined seating. It's home to our local international film festival and sometimes hosts live performances and other events. New PA sounds much better than it ever did in the past. Sound guy did some cool stuff routing thigs to the surround speakers farther back in the hall, although that wasn't audible from the front rows nor in the on-stage recording. Fun talking to him about how he routes sound through 6 busses into the cinema PA.
I'm quite familiar with the room, but had little idea of how the band would setup, nor even of exactly what instrumentation the band would include of this time. There is no raised stage area nor other demarcation of what might be considered the limits of the stage other than the first row of seating at the back edge of a large wood floor area. Arrangement of musicians was very widely dispersed across the stage area. Both those things made placement of the recording rig tricky. Would be preferable to shift far enough back toward the audience to gain an improved perspective and a more equal distance to all musician sources, but that would've placed the recording equipment in the center of the open floor area right where the musicians pass and the audience congregates. As it was I snugged it up directly in front of his music stand and guitar pedal board, slightly to stage right of center, and turned the array slightly toward stage left toward the drum kit. That places the primary guitar (also triggering midi synth) left in the soundstage and the percussionist far left. Drums are center, with bass, secondary guitar and sax/flute to the right. With the rig and recording bag placed there and a front row seat off to the side, I could quickly extend the stage-left side telescopic antenna supporting the right omni a bit more just after the musicians took the stage, then retract it again at the end of each set before it could get trampled by the audience and musicians.
Other than the array being trampled under foot, my concerns were several: Being overly close to the primary guitar amp making it too loud; No direct sight-line from snare-drum to recording position; sax/flute being overly far away on other side and potentially sounding weak, and the musician positions extending nearly 180-degrees around the recording position.
Hmmm, maybe I should have brought cables to patch a recorder into the board. I didn't bother with that as most of the time I don't need it for this instrumental act. But I had a secondary rig consisting of DPA 4061 omnis > Deity PR-2 with me, so I gaff taped that to the audience stair railing way over on the flute side of the stage just to make sure I had sufficient pickup of the flute / sax. Waking around and listening at one point during the first set, the sound at the center entrance isle through the front row was a nice blend of onstage and reinforcement from the new PA and the flute sounded well represented there, so for the second set I moved the little secondary rig there to gain a better perspective while remaining confident it would still pickup sufficient sax/flute if that ended up lacking in the primary rig recording.
During the performance the percussion guy roamed all over. Sometimes almost ticklng the omni on that side, other times walking over behind the guitar player to the drummer, over to the other side, up to the audience.. That close / far / everywhere dynamic also concerned me.
I've only had a brief chance to listen, but it worked out quite nicely. Very enjoyable, but will certainly benefit from some post processing- the dynamics are extreme, some compression will benefit the sometimes overly loud guitar, some parallel comp will benefit the flute/sax, and other quiet instrument details. Pleased that none of my concerns were out of place, but also did not end up being overly problematic.
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@ Focker, I'm really digging that Spafford recording! Very clean and tight, nice image distribution and overall feel. Fantastic on headphones last night - it was easy to put all the technical critique aspects out of mind and just enjoy it. What are your thoughts on inverting the arrangement for this one verses the way you had it setup for Pink Talking Fish? (This one using the 4017's for X/Y in the center and 4015s as the spaced pair)
Thanks gut, really happy with how this one turned out. So I've run this arrangement before, but this was the first time outdoors. I am certain this will be the preferred outdoor setup. I do want to play around with the setup indoors more to see how different configs compare. I do 90% of my taping at Ardmore Music Hall, great room with good sound. I have yet to run the widecards spread and the supercards in the center XY there, so it will be my next go. There are some things coming up in the next few weeks there where I can try it some more. Tomorrow night I have Goose at MSG taping GA from the floor towards the back. So I'm likely going to run the supercards spread wide and then use the 2015s XY at the center position, given the distance
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Dudes, Goose put on a clinic at MSG last night. They played for 4.5 hours between two sets and an encore. Allegedly the longest show in MSG history. Surpassing Phish 12/31/97 in duration. None of this is verified (yet), but the fan chatter post-show
I ran the supercards wide 2' at 30 degrees PAS and the widecards XY at 90 in the center position. Really nice turnout. I have not tracked out the whole show, but here is a snippet of them doing Kate Bush's Running Up That Hill -> Give It Time
This is like 85% supercards with a little of the widecards added in for some low end depth.
https://drive.google.com/file/d/1khnGy-VcSpaBos2KYyiWfPp2ohkNN_RU/view?usp=drive_link
edit: link to full show
https://drive.google.com/drive/folders/1IQUrTy9sL19L78lqLS4Zn-9VmmFBjr2W?usp=drive_link
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Finally getting a chance to get back to this thread to find some very nice recordings and cool setups! Very encouraging!
I did some listening last night to catch up.. (Senn HD650 headphones)
@ Thelonious- Thanks for sharing that great write-up of your recent on-stage acoustic recordings with examples, and documenting it so nicely for the rest of us. Making those kinds of comparisons is so valuable in determining what works best and which way you want to go with it. I found myself liking both examples that you included links to for somewhat different reasons.. and desiring something which embodies the best qualities of both. The omnis alone sound very natural and easy to listen to which I very much like. I also enjoy the increased clarity and somewhat more direct sounding quality of the horns in that recording. Listening to the OMT4 recording I immediately notice the top quality of of the mics used. Nice smooth timbral balance. I can hear what you mention about the increased separation - loads of stereo width, distinct placement of sources and portrayal of enveloping ambience, which are all qualities I associate with the technique. I did find myself wanting the ambient / reverberant / room stereo qualities to have a bit more of the naturalness of the omnis, but that preference may be accentuated by my listening with headphones rather than speakers.
A few thoughts on possible improvements-
1) Curious if you tried the omnis + the center CMC641 @+/-45°, XY pair without the 22's. I assume you did, and would like to hear more of your thoughts on how that worked or didn't. My initial thought is that should improve on what I hear from the omnis alone. If you did and it didn't work, perhaps the omnis needed to be spaced more widely. Also curious if you tried including just a touch of the omnis in the otherwise straight OMT4 mix, or the other way around with just a touch of the 22's in a mix of the omnis and X/Y hypers? I suspect either of those may work better than a more equal-level combination of omnis and 22's since those two pairs were positioned rather close to each other by necessity which could cause some problems when mixing them together.
2) I suspect the omnis provided more direct clarity of the horns because when placed on the floor they essentially form an upward-facing hemispherical sensitivity pattern which more or less faces directly at the standing horn players. Options for increasing clarity and direct pickup of the horns in the OMT4 setup using more directional mics might be angling either the 22's or 41's more upward to get the standing horn players more on-axis. That entails a sort of balancing of the vertical angle between facing the drums and floor level sources with the mics angled lower, verses the and horns with the mics angled higher. Might angle both pairs upward by the same amount, or just one pair or the other, which can additionally helps by increasing the differentiation between the primary focus of each pair. One thing to be careful of in regard to the upward angling of mics is how that changes pickup of the drum kit. Increased upward angle is likely to make the cymbals louder/brighter. When on-stage the mics are close enough to the drums that a relatively small change in vertical angle can be significant.
3) In this situation I might angle the 22's more widely. Not because the OMT4 mix needs more imaging width (I don't think doing so would make the direct imaging content sound "wider"), but because that would make their contribution more similar to what omnis provide in terms of room / reverberant / ambient contribution. It shouldn't be problematic because the X/Y hypers are anchoring the center part of the image. Also, because the array is placed on-stage relatively close to the sources, angling that pair somewhat more widely will be generally less problematic than it can be when recording from farther away where it might increase pickup of audience and reflections of the side walls too much.
Hey Gut, thank you for all of the advice and the feedback. It really is super helpful.
I would start with a note on playback being critical on these recordings. Depending on my playback setup, I find the DPA only recording anywhere between very good and almost unlistenable. I pulled out my HD6XX (Massdrop/Senheiser colab that I believe is sonically very similar to the HD650) and the DPA sounded pretty good. However, I do find these headphones rolled off in the treble which makes them very forgiving of poor recordings. Great for general listening but I can't master with them. With my HD800S', or my ~1980 La Scala's (which have horns and are in a small/medium sized room) I find the treble almost unlistenable on the DPA recording. This is despite having rolled off between 3 and 4 DB above 8K DB to try to address the bump from the short grills and then further to make it less harsh to my ears. I would note that I did not have this issue with the treble glare on my previous recording, from the same venue, that I recorded "binauralish" (mounted on glasses at temples) and where I applied no EQ. https://samply.app/p/Ga5WbtzNargjM4rqsvTD My theory is that my head was absorbing the reflections in that instance but, obviously, just a theory and it wasn't the same night. The difference in sound from playback matters a lot as the difference between the recordings to me comes down to the EQ primarily, with the 22/41 matrix sounding very polished and pleasant on my systems with high end extension and the DPAs sounding bright and harsh. This is also true of the horns where there is a bite, particularly with the trumpet, that the 22s tame well. I suspect this is partially due to frequency response of the mics and partly due to the trumpet being more off axis from the mic compared to the Omni. I suspect I could EQ the omnis more and get them closer to the profile I want, however, I'm still developing that skill and am also trying to align on a mastering headphone that I trust as "accurate" from which to make adjustments.
I did create a matrix with the Omnis as the base and bringing in the XY, similar to what I did with the 22s, but I found something that sounded "off" that I attributed to the open pattern of the omnis being too close to the XY but, in hindsight, it could have been due to the treble in the DPA recording.
I had also tried a matrix with all 3 (Omnis being primary and the 22s and 41s mixed in) but this sounded really off and, again, I assumed it was due to the lack of distance (in particular between the 22s and the omnis placed directly below them). I still had these on my hard drive so I've uploaded the same two songs from this matrix here https://samply.app/p/D0BNOBkFIAZyHLlBlH0A . I could certainly try adding in a bit of the omnis to the 22/41 matrix but I will need to eq the omnis again as I find them uncomfortable to listen to.
I do think that ideal would have been to have omnis set up another 3 feet to each side (5' each side of centre) however, that wasn't feasible for this outing as there was a limitation of space among other factors.
I had set up the 41s so that they were aimed at the snare, as you had suggested. This plane also captured some bass and guitar, and it allowed me to bring both of these up. The saxophone player, also stood quite close to the centre and, given the sound projecting from the keys as well as the bell, I thought the overall timbre and mix of the sax was good. The trumpet was a challenge because Ed moves around the stage. I was thinking next time I could angle just the far right 22 up ~30degrees. I wouldn't want to do this on the left as it would be all cymbals, but on the right this would better align with the area the trumpet was most of the time. Do you think making an adjustment to one side of the pair like that would be okay in this context? The ideal would be to set up omnis (maybe 414s) at about 3' high on either side and 5' each side of centre that I could dial in as wanted after the fact but I would need to ensure I'm not taking up too much of the bands space on a small stage and it woudl require two more mic stands, which is not a small increase in gear/set up.
With respect to angling the 22s more widely, I already had them at +/-55 degrees and spaced 2'. This was done to ensure that nothing was completely outside of the 22 pair, thinking that would help with the image, without going too wide to increase the angle off axis of the mics (to which I attribute the roll off of the high end of the trumpet). Do you think there is an advantage to going wider than that? If I was going to make a change to the mic angles my instinct was to increase the angle of the right mic up by 25 degrees to better capture the area the trumpet was 90% of the time. That said, I'm open to trying a wider angle between the 22s if you think it would be helpful.
Focker - Thank you for the shows you have uploaded. I enjoyed the last recording (incredible sense of being in the room) and i have downloaded your monster Goose show to give it a listen. I'm learning a lot from the files you are sharing so thank you again!
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Dudes, Goose put on a clinic at MSG last night. They played for 4.5 hours between two sets and an encore. Allegedly the longest show in MSG history. Surpassing Phish 12/31/97 in duration. None of this is verified (yet), but the fan chatter post-show
I ran the supercards wide 2' at 30 degrees PAS and the widecards XY at 90 in the center position. Really nice turnout. I have not tracked out the whole show, but here is a snippet of them doing Kate Bush's Running Up That Hill -> Give It Time
This is like 85% supercards with a little of the widecards added in for some low end depth.
https://drive.google.com/file/d/1khnGy-VcSpaBos2KYyiWfPp2ohkNN_RU/view?usp=drive_link
edit: link to full show
https://drive.google.com/drive/folders/1IQUrTy9sL19L78lqLS4Zn-9VmmFBjr2W?usp=drive_link
I listened to the excerpt. Nice even tone across the spectrum. Vocals were pleasant, and the room sound is perfect for MSG. Nice work!
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Focker - Thank you for the shows you have uploaded. I enjoyed the last recording (incredible sense of being in the room) and i have downloaded your monster Goose show to give it a listen. I'm learning a lot from the files you are sharing so thank you again!
Hey I'm happy to share and glad it's helping out. I've been really enjoying these setups and have been learning a great deal myself. I'll say this in general....I feel like I've been getting consistently better recordings running the OMT4 setup than any other setup I've ever run. I try to think of each situation as running a main pair and a support pair, and then putting them in a position to play to their strengths. So generally speaking, if I'm outdoors or up close then the widecards will be the main pair spread wide and if I'm in a bad room or far away (or even just potentially being indoors - I’m still working on this one) then the supercards will play the main role spread wide. The one thing I have felt most strongly about is PAS (or more accurately really narrow spreads of 0 or 30* given my fixed angle clips) and the main pair I'm running on the outside
Now I need to tinker more with the support roles in those different scenarios. For the hypers xy in the middle, they’ve been doing a phenomenal job. I’m more interested in playing with cards in the center for bad rooms and even playing around with widecard angles and spacing a bit more.
But ideally I’d like to be at a place where two pairs of mics can handle every scenario and that feels like where I’m at now.
Hoping the access to the raw files helps folks see the starting points too
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I listened to the excerpt. Nice even tone across the spectrum. Vocals were pleasant, and the room sound is perfect for MSG. Nice work!
Many thanks!
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…I try to think of each situation as running a main pair and a support pair, and then putting them in a position to play to their strengths. So generally speaking, if I'm outdoors or up close then the widecards will be the main pair spread wide and if I'm in a bad room or far away (or even just potentially being indoors - I’m still working on this one) then the supercards will play the main role spread wide. The one thing I have felt most strongly about is PAS (or more accurately really narrow spreads of 0 or 30* given my fixed angle clips) and the main pair I'm running on the outside
So I listened to the clip from the recent Goose show. Wonderful sense of space and none of the boominess that I would worry about from recording at the back of an arena. I have been thinking about how to apply OMT for up front at acoustic shows where the sources are spread across an area. Your method of thinking about PAS is both 2 pairs is helpful. When I recorded the brothers at MSG, I used hypers and tried to get them as on axis as possible (don’t have sufficient spacing to get the angle I wanted). That worked out well, but, your recording has a more open sense of space and the bass you got from adding the sub cards in the centre sounds more natural than the EQ I added to my recording. This is a really good recording from MSG, like shockingly good imo. Thanks again!
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…I try to think of each situation as running a main pair and a support pair, and then putting them in a position to play to their strengths. So generally speaking, if I'm outdoors or up close then the widecards will be the main pair spread wide and if I'm in a bad room or far away (or even just potentially being indoors - I’m still working on this one) then the supercards will play the main role spread wide. The one thing I have felt most strongly about is PAS (or more accurately really narrow spreads of 0 or 30* given my fixed angle clips) and the main pair I'm running on the outside
So I listened to the clip from the recent Goose show. Wonderful sense of space and none of the boominess that I would worry about from recording at the back of an arena. I have been thinking about how to apply OMT for up front at acoustic shows where the sources are spread across an area. Your method of thinking about PAS is both 2 pairs is helpful. When I recorded the brothers at MSG, I used hypers and tried to get them as on axis as possible (don’t have sufficient spacing to get the angle I wanted). That worked out well, but, your recording has a more open sense of space and the bass you got from adding the sub cards in the centre sounds more natural than the EQ I added to my recording. This is a really good recording from MSG, like shockingly good imo. Thanks again!
Also agree- REALLY GOOD recording
Focker can comment, but at Goose they were at the back of the GA floor, which, IMO, is possibly the best place to record AUD from. The arena is so large, that at that spot, you are basically in the center, possibly only 100 feet from the stacks.
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Focker can comment, but at Goose they were at the back of the GA floor, which, IMO, is possibly the best place to record AUD from. The arena is so large, that at that spot, you are basically in the center, possibly only 100 feet from the stacks.
Yes, we were about 3/4s of the way back on the floor. Sound was superb imo and I'm really happy with the tapes. Thanks for the compliments!
Same to you Thelonius!
I'm still reeling from the show to be honest, its easily a top 5 ever show in my book, from any band, and I like to think I've got some mileage under my belt.
Here is Jon Pasternaks source from MSG for some comps. Neumann shotguns -> 248, also sounds really good
https://archive.org/details/goose2025-06-28.Pasternak.NeumannKMR82i.Flac24
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Right on! Looking forward to giving that MSG Goose a listen. FOCKER, fully agreed with your comment about "..putting them in a position to play to their strengths". Seems like good choices and a logical path forward to me.
Here's my take on the key aspects you are juggling:
Baseline setup when not constrained by acoustics such as when recording outdoors: X/Y hypers in the center + subcards as the spaced pair. Inherent advantages of using the more open-pattern pattern in a spaced configuration are improved low frequency / off-axis / reverberant qualities, combined with the tighter-pattern X/Y pair providing clear and distinct imaging across the center of the playback image. This combination has each pair playing to its inherent strengths, resulting in the best of both worlds. A great combination and one I'm very familiar with.
Question then becomes, what about in a less ideal acoustic situation? In a more constrained acoustic, flipping that arrangement "inside out" like you are doing may prove useful. Why that might be so is interesting for me to think about, out loud as it were..
Doing that switches the more-directional hyper pair out to the spaced position, where they can be angled more narrowly / on-axis / PAS for good clarity while still achieving decent stereo separation due to the wider spacing. The same would not occur when using that pair in the center coincident X/Y position at the same narrow angle (at least without any post-production mid/side ratio adjustment being made to increase stereo width). At the same time, the subcards are moved from the spaced position to the center X/Y position, and I presume remain relatively widely angled. < not sure if that's the case or if you also angle the X/Y 4015's more narrowly so as to be more on-axis / PAS. Either way, this sort of turns the previous arrangement inside out so we're getting most of the direct clarity from the wider spaced position, and more of the immersive ambience and depth from the center pair. In either case, the spaced pair is the one that ends up being the primary pair in the mix. Does that accurately describe what you're doing?
That's somewhat different than what happens in my OMT8 arrangement where there are always wide-spaced omnis in use which just end up contributing a lot less to the mix when in more challenging acoustics, while the central part of the array (think of that as the OMT4 part) consisting of the coincident center pair and flanking near-spaced pair, are both highly directional. In my case when indoors and when farther back I also angle the near-spaced pair more narrowly / more on-axis / more PAS (and would also increase the spacing of that pair to compensate for the more narrow angle if my setup allowed for doing that). So in that way its very similar to what you are doing. What is different is the center pair remains highly directional, its just that a different amount of the wide-spaced omnis end up being used.
There are times when I think I might like to change the directivity of my center Mid, but interestingly by going in the opposite way - shifting to a wider pattern when up close or on stage. So this is one of the things that's very thought provoking for me.
Thanks for sharing these great recordings! More comments after I can give a listen.
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Thelonious, I've some thoughts on your post I'll also get to later. Good stuff.
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Doing that switches the more-directional hyper pair out to the spaced position, where they can be angled more narrowly / on-axis / PAS for good clarity while still achieving decent stereo separation due to the wider spacing. The same would not occur when using that pair in the center coincident X/Y position at the same narrow angle (at least without any post-production mid/side ratio adjustment being made to increase stereo width). At the same time, the subcards are moved from the spaced position to the center X/Y position, and I presume remain relatively widely angled. < not sure if that's the case or if you also angle the X/Y 4015's more narrowly so as to be more on-axis / PAS. Either way, this sort of turns the previous arrangement inside out so we're getting most of the direct clarity from the wider spaced position, and more of the immersive ambience and depth from the center pair. In either case, the spaced pair is the one that ends up being the primary pair in the mix. Does that accurately describe what you're doing?
Thats exactly what I'm describing yes. I love the spaced supercards on the outside when the room / position dictates it and I'm more or less trying to figure out how I can add the widecards into the mix. I've only run the widecards XY at 90* in the center position so far. The results have been positive. They are adding the low end and giving a sense of depth but have been so minor in the final mix the difference is subtle but there when you listen for it. I've been giving thought to other ways to add them in in that center position and play with angles, spacing but to be honest I don't know if any changes would be significantly different..but half the fun is in trying different things out.
I will say the spaced widecards and supercards XY in the center have been wonderful.
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A list of FOCKER's OMT4 options for use indoors. The ones I feel are worth consideration are bolded:
(A) Options using the widecardioids in the spaced position (in order of increasing foreword sensitivity)
A1) Same as the outdoors baseline setup.
A2) Widecards spaced ~24" and angled 90º (+/-45º) + hypercards X/Y in the center, using a narrow X/Y angle that places the hypers in PAS (the angle which achieves PAS is going be significantly less than 90º, so pointing just outside of stacks is a reasonable target).
^
I suspect this may work very nicely indoors. A narrow X/Y angle that achieves PAS won't produce much stereo separation, but having that pair on-axis with the PA will produce maximum image clarity and detail in the center part of the mix. The stereo width, room feel, and solid bottom will be contributed by the spaced widecards angled 90º.
Taking it further if you want... when doing the mix afterwards you might play around with adjusting the stereo width of the center X/Y pair. The straight starting point is with the X/Y pair hard-panned fully Left/Right. If you want more dry upfront clarity / less reverberance at the cost of some stereo width, you can pan both of the X/Y hyper channels toward center. Panning them fully center will roughly equate to a single cardioid pointed directly foreword. If you want more stereo width at the cost of increased reverberance and room, you can push the X/Y pair past fully hard-panned into "super stereo" (which is the same as decreasing the ratio of Mid verses Side). Pushed to the full extreme of no Mid at all / 100% Side equates to a single sideways facing fig-8 in the center.
A3) Same as above but with the widecards also in PAS.
^ This angles both pairs narrowly in PAS. It will maximize clarity and "reach" but at the expense of stereo width, openness and naturalness. Ideally the widecards would also be spaced more widely of possible to somewhat compensate for the narrower angle.
This wont sound as open, 3-dimentional and natural, but it does everything possible (other than also switching the widecards to a tighter pattern) to accommodate an distant, boomy, overly reverberant recording position. Dealing with that pretty much overshadows everything else.
(B) Options which flip the arrangement inside out, using the hypercards in the spaced position (in order of increasing foreword sensitivity)
B1) Hypercards spaced ~24" and angled 90º (+/-45º) + widecards X/Y angled 90º (+/-45º) in the center. Meh. I see little reason to do this. Same forward directionality as the outdoor baseline setup but is not "playing to the strengths of each pair".
B2) Same as above but with the X/Y widecards angled for PAS. Meh. Center config is slightly more forward biased than B1 with less stereo width.
B3) Hypercards spaced ~24" and angled PAS + widecards X/Y angled widely, say something like 120º in the center. This is a more interesting one. Direct on-axis clarity provided by from the hypercard pair. A bit more openness and depth from the widecardioid pair. This one plays to the strengths of each mic pattern, but the configuration in which each is used does not.
B4) Same as above with the widecard X/Y pair angled angled 90º (+/-45º) in the center. I think this may be what you've tried. Somewhat less room / more forward bias from the center pair.
B5) Both pairs in PAS. Meh. Same as A3 in terms of forward sensitivity bias. But without either pair playing to their strengths.
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Attentional options indoors include forgoing the widecardioids for regular cardioids or super/hypers, but one of the goals here is using those sweet sounding 4015's if at all possible
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Dudes, Goose put on a clinic at MSG last night. They played for 4.5 hours between two sets and an encore. Allegedly the longest show in MSG history. Surpassing Phish 12/31/97 in duration. None of this is verified (yet), but the fan chatter post-show
I ran the supercards wide 2' at 30 degrees PAS and the widecards XY at 90 in the center position. Really nice turnout. I have not tracked out the whole show, but here is a snippet of them doing Kate Bush's Running Up That Hill -> Give It Time
This is like 85% supercards with a little of the widecards added in for some low end depth.
https://drive.google.com/file/d/1khnGy-VcSpaBos2KYyiWfPp2ohkNN_RU/view?usp=drive_link
edit: link to full show
https://drive.google.com/drive/folders/1IQUrTy9sL19L78lqLS4Zn-9VmmFBjr2W?usp=drive_link
This is a crazy good tape of a crazy good show. NICE WORK!
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Hey Thelonious-
I'm breaking up my replies to your post up into three parts. 1st, thoughts on monitoring and the different needs of mixing verses mastering-
I would start with a note on playback being critical on these recordings. Depending on my playback setup, I find the DPA only recording anywhere between very good and almost unlistenable. I pulled out my HD6XX (Massdrop/Senheiser colab that I believe is sonically very similar to the HD650) and the DPA sounded pretty good. However, I do find these headphones rolled off in the treble which makes them very forgiving of poor recordings. Great for general listening but I can't master with them. With my HD800S', or my ~1980 La Scala's (which have horns and are in a small/medium sized room) I find the treble almost unlistenable on the DPA recording. This is despite having rolled off between 3 and 4 DB above 8K DB to try to address the bump from the short grills and then further to make it less harsh to my ears.
You've astute ears. Agreed that the HD600 and HD650 which I generally use for assessing and general listening are somewhat forgiving in a few ways. I find them just about right for general listening, but not the best tool for precise EQ decisions (the HD700s I have on hand are out of operation and in need of repair are better in that regard as they are far more detailed, yet have their own quirks - such as an annoying tinnitus-aggravating 7Khz peak).
I've not used HD800S but would like to try them. I have read that their response has a bit of a peak around 11khz, which is the approximate corner frequency of the peak imparted by the DPA406X short grids. It may be that match up perceptually aggravates the excessive energy of the DPA response in that region when using those 'phones more than it does though others. A similar thing may be happening with the La Scala's, as classic Klipsh horns are well known for being rather energetic in the treble. Two ways to look at that - as feature or bug - and as a feature it perhaps makes for a good tool in highlighting that particular response bump issue in the DPAs so that you might correct it with EQ.
You are no doubt aware that the generally perceived response of various headphones is more or less consistent from listener to listener, yet the more specific perceived response details tend to vary substantially from person to person, particularly in the upper midrange and treble. A consequence of headphones being close-coupled to the ear and the interaction of fit, pina-shape details and ear-canal resonance varying from person to person..
[and (out of order) from later in your post..]
The difference in sound from playback matters a lot as the difference between the recordings to me comes down to the EQ primarily, with the 22/41 matrix sounding very polished and pleasant on my systems with high end extension and the DPAs sounding bright and harsh. This is also true of the horns where there is a bite, particularly with the trumpet, that the 22s tame well. I suspect this is partially due to frequency response of the mics and partly due to the trumpet being more off axis from the mic compared to the Omni. I suspect I could EQ the omnis more and get them closer to the profile I want, however, I'm still developing that skill and am also trying to align on a mastering headphone that I trust as "accurate" from which to make adjustments.
I keep meaning to make time to dive more deeply into response correction for headphones as a way of making them more useful for objective tasks like mastering. There are plenty of corrective filter tools for headphones, but most are generic to the headphone model and not specifically tuned to the listeners own HRTF. In my limited experience a number of years back, none of those generic headphone response correction tools I tried were really good enough. It took a personalized calibration to get something really usable. Still want to get around to exploring that more deeply. Maybe they are better now, maybe I just need to delve into a personalized HTRF correction using the right headphones as starting point. Until then, I trust good monitors that have been calibrated for in room response more than headphones when it comes to reliable tonal response details.
Might be a good opportunity to work on EQ skills to make that DPA peak acceptable. Lacking a truly objectual trustworthy headphone response that might entail comparing on both sets of phones along with the awareness of how both are somewhat incorrect in that region only in opposite ways, then shooting for something that sort of splits the difference, or at least makes it bearable on 800S and the La Scalas.
This all gets to the important difference between relative and absolute response. Mixing primarily deals with relative response - getting everything to work right together, the relationship of things to other things in the mix itself, and that can be done with monitoring that is less than objective as long as you can identify those relative differences. Mastering is more difficult because it attempts to deal with absolute response - how your mix translates beyond your own monitoring to the outside world. Far more challenging to get really right.
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EQing-
I would note that I did not have this issue with the treble glare on my previous recording, from the same venue, that I recorded "binauralish" (mounted on glasses at temples) and where I applied no EQ. https://samply.app/p/Ga5WbtzNargjM4rqsvTD My theory is that my head was absorbing the reflections in that instance but, obviously, just a theory and it wasn't the same night.
I generally find head-baffled omnis, like Jecklin-disk baffled omnis, to have less treble-emphasis than the same pair of omnis does when used without a baffle. Sometimes J-disk recordings come to life with a touch of treble boost because of that. Not exactly sure why, could be frequency specific absorption by the baffle, reduced acoustic cross-talk and phase interaction between channels at those frequencies due to the presence of the baffle, or something else. It is a thing I've noticed in any case.
Again, another situation where some subtle EQ correction can be quite valuable.
I did create a matrix with the Omnis as the base and bringing in the XY, similar to what I did with the 22s, but I found something that sounded "off" that I attributed to the open pattern of the omnis being too close to the XY but, in hindsight, it could have been due to the treble in the DPA recording.
I had also tried a matrix with all 3 (Omnis being primary and the 22s and 41s mixed in) but this sounded really off and, again, I assumed it was due to the lack of distance (in particular between the 22s and the omnis placed directly below them). I still had these on my hard drive so I've uploaded the same two songs from this matrix here https://samply.app/p/D0BNOBkFIAZyHLlBlH0A . I could certainly try adding in a bit of the omnis to the 22/41 matrix but I will need to eq the omnis again as I find them uncomfortable to listen to.
I suspect its that somewhat peaky high frequency response from the omnis. Might be insightful to attenuate the highs in the omnis more than you otherwise might (EQ the omnis to sound somewhat dull in isolation without any of that high frequency problem) and see if the omnis work better in the mix that way. Going further, you might try low passing the omnis down where the response of directional mics naturally starts to roll off. At that point they are only extending the really low frequency content the other mics don't really get. Having them positioned "overly close" to the other pair then might actually work to advantage. Other folks really like using omnis that way.
I do think that ideal would have been to have omnis set up another 3 feet to each side (5' each side of centre) however, that wasn't feasible for this outing as there was a limitation of space among other factors.
Does help to get the omnis wider for a few reasons when you want to use their full frequency response, such as I prefer doing. One reason is less potential problematic phase interaction with other mics that are overly close, if not chopping off everything above a certain frequency range where the closely positioned mics may be interacting.
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Angling certain mics in the array differently when close to the musicians-
[snip..]I was thinking next time I could angle just the far right 22 up ~30degrees. I wouldn't want to do this on the left as it would be all cymbals, but on the right this would better align with the area the trumpet was most of the time. Do you think making an adjustment to one side of the pair like that would be okay in this context? The ideal would be to set up omnis (maybe 414s) at about 3' high on either side and 5' each side of centre that I could dial in as wanted after the fact but I would need to ensure I'm not taking up too much of the bands space on a small stage and it woudl require two more mic stands, which is not a small increase in gear/set up.
With respect to angling the 22s more widely, I already had them at +/-55 degrees and spaced 2'. This was done to ensure that nothing was completely outside of the 22 pair, thinking that would help with the image, without going too wide to increase the angle off axis of the mics (to which I attribute the roll off of the high end of the trumpet). Do you think there is an advantage to going wider than that? If I was going to make a change to the mic angles my instinct was to increase the angle of the right mic up by 25 degrees to better capture the area the trumpet was 90% of the time. That said, I'm open to trying a wider angle between the 22s if you think it would be helpful.
Yeah, point them differently however you need too. The relationship of the mic array geometry verses mix-down routing geometry verses playback system geometry is really interesting. In one sense we aim to set up the microphone array geometry in such a way that we capture an accurate picture of the acoustic situation in the room. Maintaining that accuracy is more important if we are playing back using a speaker geometry that is similar to the recording array geometry. If recording using two mic channels and playing back over two speakers or headphones, you don't really want to angle one mic too oddly in comparison to the other or it will tend to throw other things out of whack despite what you are trying to correct. Similarly, if you were trying to record for surround playback using an array of more than two microphones, you'd wouldn't want to vary the angle relationship between mics in the array too much so as to maintain a reasonable degree of accuracy upon playback. Maintaining a "convicning illusion" is probably a better way of putting it. But we aren't doing that, we don't have a parity between recording channels and playback channels. We're recording more than two mic channels but mixing down to just 2-channels in stereo. That allows for more freedom in angling mics up or down as needed to balance things. The other mics in the array help cover for that in the mix.
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Hey Gut, thanks as always for the thoughtful response. It's very helpful and I'm always learning something
I've not used HD800S but would like to try them. I have read that their response has a bit of a peak around 11khz, which is the approximate corner frequency of the peak imparted by the DPA406X short grids. It may be that match up perceptually aggravates the excessive energy of the DPA response in that region when using those 'phones more than it does though others. A similar thing may be happening with the La Scala's, as classic Klipsh horns are well known for being rather energetic in the treble. Two ways to look at that - as feature or bug - and as a feature it perhaps makes for a good tool in highlighting that particular response bump issue in the DPAs so that you might correct it with EQ.
The HD800S (as opposed to the 800) has a treble peak around 6K. It is reduced from the original 800 but still there. It is, as you say, both a feature and a bug as it presents "soundstage" unlike any other headphone I've tried, but it does not play well with recordings that also have treble peaks the particular DPA recording in question being one.
With respect to the monitoring for mastering I'm experimenting with a Quedelix 5K https://www.qudelix.com/products/qudelix-5k. Users have created custom parametric EQs for many current headphones and I am finding it promising for use with IEMs, where I can bypass the HRTF issue. It is definitely going to be my travel mixing/mastering solution.
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I did create a matrix with the Omnis as the base and bringing in the XY, similar to what I did with the 22s, but I found something that sounded "off" that I attributed to the open pattern of the omnis being too close to the XY but, in hindsight, it could have been due to the treble in the DPA recording.
I had also tried a matrix with all 3 (Omnis being primary and the 22s and 41s mixed in) but this sounded really off and, again, I assumed it was due to the lack of distance (in particular between the 22s and the omnis placed directly below them). I still had these on my hard drive so I've uploaded the same two songs from this matrix here https://samply.app/p/D0BNOBkFIAZyHLlBlH0A . I could certainly try adding in a bit of the omnis to the 22/41 matrix but I will need to eq the omnis again as I find them uncomfortable to listen to.
I suspect its that somewhat peaky high frequency response from the omnis. Might be insightful to attenuate the highs in the omnis more than you otherwise might (EQ the omnis to sound somewhat dull in isolation without any of that high frequency problem) and see if the omnis work better in the mix that way. Going further, you might try low passing the omnis down where the response of directional mics naturally starts to roll off. At that point they are only extending the really low frequency content the other mics don't really get. Having them positioned "overly close" to the other pair then might actually work to advantage. Other folks really like using omnis that way.
Applying more aggressive EQ to the high end of the DPAs, and using that to mix in with the other mics, is a great suggestion and I will definitely try that. The ability to bring in a bit more of the off axis trumpet, along with some audience and PA announcements, without causing the interference or increasing harshness would be ideal. I fully agree on preferring to use the full range response of the omnis, I just think I need to have them either much further, or closer, to the other mics.
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A list of FOCKER's OMT4 options for use indoors. The ones I feel are worth consideration are bolded:
(A) Options using the widecardioids in the spaced position (in order of increasing foreword sensitivity)
A1) Same as the outdoors baseline setup.
A2) Widecards spaced ~24" and angled 90º (+/-45º) + hypercards X/Y in the center, using a narrow X/Y angle that places the hypers in PAS (the angle which achieves PAS is going be significantly less than 90º, so pointing just outside of stacks is a reasonable target).
^
I suspect this may work very nicely indoors. A narrow X/Y angle that achieves PAS won't produce much stereo separation, but having that pair on-axis with the PA will produce maximum image clarity and detail in the center part of the mix. The stereo width, room feel, and solid bottom will be contributed by the spaced widecards angled 90º.
Taking it further if you want... when doing the mix afterwards you might play around with adjusting the stereo width of the center X/Y pair. The straight starting point is with the X/Y pair hard-panned fully Left/Right. If you want more dry upfront clarity / less reverberance at the cost of some stereo width, you can pan both of the X/Y hyper channels toward center. Panning them fully center will roughly equate to a single cardioid pointed directly foreword. If you want more stereo width at the cost of increased reverberance and room, you can push the X/Y pair past fully hard-panned into "super stereo" (which is the same as decreasing the ratio of Mid verses Side). Pushed to the full extreme of no Mid at all / 100% Side equates to a single sideways facing fig-8 in the center.
A3) Same as above but with the widecards also in PAS.
^ This angles both pairs narrowly in PAS. It will maximize clarity and "reach" but at the expense of stereo width, openness and naturalness. Ideally the widecards would also be spaced more widely of possible to somewhat compensate for the narrower angle.
This wont sound as open, 3-dimentional and natural, but it does everything possible (other than also switching the widecards to a tighter pattern) to accommodate an distant, boomy, overly reverberant recording position. Dealing with that pretty much overshadows everything else.
(B) Options which flip the arrangement inside out, using the hypercards in the spaced position (in order of increasing foreword sensitivity)
B1) Hypercards spaced ~24" and angled 90º (+/-45º) + widecards X/Y angled 90º (+/-45º) in the center. Meh. I see little reason to do this. Same forward directionality as the outdoor baseline setup but is not "playing to the strengths of each pair".
B2) Same as above but with the X/Y widecards angled for PAS. Meh. Center config is slightly more forward biased than B1 with less stereo width.
B3) Hypercards spaced ~24" and angled PAS + widecards X/Y angled widely, say something like 120º in the center. This is a more interesting one. Direct on-axis clarity provided by from the hypercard pair. A bit more openness and depth from the widecardioid pair. This one plays to the strengths of each mic pattern, but the configuration in which each is used does not.
B4) Same as above with the widecard X/Y pair angled angled 90º (+/-45º) in the center. I think this may be what you've tried. Somewhat less room / more forward bias from the center pair.
B5) Both pairs in PAS. Meh. Same as A3 in terms of forward sensitivity bias. But without either pair playing to their strengths.
gut, as always I appreciate the in-depth and thoughtful responses, You are correct with what I've tried. I think for me it's really been a good deal of experimentation to see what sticks and what doesn't. The truth is I've been super happy with all the different configs and the results I've gotten. As I said above I feel like the quality of all the tapes I've made have been really good in all the different arrangements moving from 2 channel to OMT4. I have two shows tonight and tomorrow with a local dead cover bands at Ardmore Music Hall where I'm going to test out a couple varieties mentioned above. I'll post the results this week for some input. It's a small room, good sound and not too far from the stacks, I'm going to do a flavor with the widecards spaced and then the superards spaced. I think I'll have enough info at this stage to sort of settle into what seems to be the most consistent / desirable to my ears in this specific room. Either way I'm having a ton of fun just playing around! Will keep the samples coming.
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Right on. Nice to be approaching what seems the point of diminishing returns where we're mostly tweaking details, having already achieved the most significant advancements by way of the general concept. That's kind of where I feel we are with all of this at this point. Thanks for taking it up, sharing your thoughts and recordings and helping to refine it to the nth degree.
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Our latest effort- an OMT6 at Phish SPAC night1
https://taperssection.com/index.php?topic=207845.0
We ran kindms AKGc34 in the middle DFC in the OTS int a Sonosax SX-M2D2; I took a digi feed and added a pair of AKG ck8's PAS and DPA 4060's spread 10 feet on other stands.
All in all a great experience; show and recording wise.
PHISH
2025-07-25 FRIDAY
Broadview Stage at SPAC
Saratoga Springs NY
MDAUD OMT6
microphones:
ch1/2: DPA 4060 Omnis spread 10 feet apart > Grace V2 sn001 >
ch3/4: AKG ck8 supercardioids PAS > Grace V2 >
ch5/6: AKG c34 M/S [ Mid=cardioid; Side=fig 8 ] >
recorder: Tascam DR680|SD
processing: SD|Audacity|cdwaveditor|TLH|foobar2000 tagger
recorded by: Kyle Holbrook; Michael Deary
processed by: Kyle Holbrook
SET 1:
d1t01. First Tube
d1t02. Bathtub Gin
d1t03. Devotion To a Dream
d1t04. The Well
d1t05. Birds of a Feather
d1t06. Strawberry Letter 23
d1t07. Lawn Boy
d1t08. The Old Home Place
d1t09. Hey Stranger
d1t10. Walls of the Cave
SET 2:
d2t01. Set Your Soul Free >
d2t02. Chalk Dust Torture ->
d2t03. Beneath a Sea of Stars Part 1 ->
d2t04. Piper >
d2t05. Everything's Right
d2t06. encore break
d2t07. Loving Cup >
d2t08. Run Like an Antelope
Following Lawn Boy, Trey introduced Page as "The Chairman of the Mound."
Setlist from phish.net
edited to add rig pics: This night I only got a shot of our stand, no DPA's in the shot.
That is kindms' AKGc34 anchoring the middle and the AKGck8's aimed PAS.
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Thanks Kyle! Now back home again I've got something to listen to tonight!