Topic: Mic Setup...Mounting Bars vs. Free Style

[stevetoney]

Just a reminder that if you typically like DIN but your PAS arrangement at any particular venue has you using less angle between mics, which it will in most situations, it will be advantageous to compensate for the narrower angle between mics by introducing more spacing between them. [snip]

Avoiding the "explain this like I'm 5 years old" question, this is based on a relatively specific relationship between the mic spacing and your speaker playback system correct?  If you are playing back through headphones, or have a specific spacing of speaker playback, that will change the relative angle/spacing of your mics, will it not?

In the end, if you're taping primarily for yourself, it should all be calculated in reference to your playback system right?

Well technically yes, however the same applies to any microphone setup: X/Y, ORTF, NOS, or what have you, each of which assume a more or less defacto 60degree speaker angle stereo listening triangle setup.  In a practical sense, variations in specific playback system speaker setup angle don’t matter as much as one might be lead to believe.  The resulting Stereo Recording Angle from any of those setups effects the position at which sounds appear to be reproduced somewhere between the two speakers or directly from them- the relative position doesn’t change much if the speakers are setup at a different angle than 60 degrees, within reason.

The table I posted above is based on the Williams’ Stereo Zoom (a link to the Stereo Zoom paper and explanatory thread here are stickied at the top of this forum) and the values in the table were derived from this on-line calculator- http://www.sengpielaudio.com/HejiaE.htm

I'm not sure I understand either the question or the response, but just to try to clarify what I think I'm reading, the Stereo Zoom concept is about stereo imaging produced by two directional microphones.  In that respect, it's all about what we're trying to achieve at the point of capture in mic'ing up a room, and most rooms have PA speakers on the stage of a venue...it's about reproduction the sound imaging experienced in the room as closely as possible by those two microphones.  (For example, if you're facing the stage and straight ahead is considered 12 noon, if the drums are physically located on stage at 10 oclock, you'd ideally like them to sound like they're at 10 oclock on your recording...but if you don't use the correct SRA and spacing, they might sound in the recording as if they were located at 9 oclock or 11 oclock.)

Please correct me if I'm wrong Lee because it's been awhile since I read and re-read (15 times or so) the article, but the article is not about the playback speakers in your living room.  I think the assumption of the article is that in order to accurately hear what you've captured at the venue, you're listening and evaluating through an 'honest' stereo playback system.  In other words, you can't expect to hear the true results of the capture on playback if your playback system is somehow biased or you're not listening in a sweet spot location.

[achalsey]

I think the assumption of the article is that in order to accurately hear what you've captured at the venue, you're listening and evaluating through an 'honest' stereo playback system.  In other words, you can't expect to hear the true results of the capture on playback if your playback system is somehow biased or you're not listening in a sweet spot location.

This was basically my question and I'm pretty sure you've answered it as well for the most part.

But, another side of my question though was about this though:

it's about reproduction the sound imaging experienced in the room as closely as possible by those two microphones.

That reproduction has to be based on a specific ratio of your playback as well though, right?  Gutbucket says the angle is based on ~60 degrees, though that can differ to a certain extent.  Then the spacing between the speakers has to be a relatively specific number as well right?  Running DIN with a playback of 4' between the speakers and 15' would affect the image.

[Gutbucket]

I'm not sure I understand either the question or the response, but just to try to clarify what I think I'm reading, the Stereo Zoom concept is about stereo imaging produced by two directional microphones.  In that respect, it's all about what we're trying to achieve at the point of capture in mic'ing up a room, and most rooms have PA speakers on the stage of a venue...it's about reproduction the sound imaging experienced in the room as closely as possible by those two microphones.

It’s about exercising control over the imaging as well as and other aspects like the reverberant balance and the qualities of the sound arriving from well off-axis.  At best, you can use that control to push things toward what you want, which might be reproducing things as ‘closely as possible’ or might be modifying  aspects to better optimize them. 

(For example, if you're facing the stage and straight ahead is considered 12 noon, if the drums are physically located on stage at 10 oclock, you'd ideally like them to sound like they're at 10 oclock on your recording...but if you don't use the correct SRA and spacing, they might sound in the recording as if they were located at 9 oclock or 11 oclock.)

It provides the understanding to control that, but I don’t really care if the drums image at exactly 10 o’clock or not and I doubt anyone else does either.  I do want a nice open clear and distinct image across the playback stage, with things in their correct place, a nice width to the band, and an enveloping ambience, with all that in balance.  I think of it more in terms of controlling the apparent playback width and depth, minimizing undesirable distortion of perspective.

Please correct me if I'm wrong Lee because it's been awhile since I read and re-read (15 times or so) the article, but the article is not about the playback speakers in your living room.  I think the assumption of the article is that in order to accurately hear what you've captured at the venue, you're listening and evaluating through an 'honest' stereo playback system.  In other words, you can't expect to hear the true results of the capture on playback if your playback system is somehow biased or you're not listening in a sweet spot location.

That and the follow up questions after the break..

[Gutbucket]

One assumption underlying most stereo recording techniques is that the speakers are 60 degrees apart.  That’s what recording labels, studios, radio stations, equipment manufacturers, engineers, researchers and amateurs like us all accept as a de facto standard. It helps to have a standard we can all agree on so  we are talking the same language.  It’s a more or less agreed on thing which specifies one aspect of Steve's 'honest' stereo playback system.

Likewise a pair of speakers 60 degrees apart is what was used in testing the listeners to generate the imaging location data upon which the Stereo Zoom curves are based (I checked once upon a time and William’s notes that somewhere, an AES paper probably. I don’t recall it being noted specifically in the SZ usage paper PDF, but the source is referenced there I’m sure). 

So the information given on the Stereo Zoom charts does assume that a ‘normal’ stereo speaker setup will be used to play the recording back.  But, what is most important about the Stereo Zoom is not figuring out the precise measurement in degrees of things but in the relative position and relationships.  The Stereo Zoom can help to set things up to get a nice wide and stable image that isn’t clumped in both speakers, regardless if they are setup 40 or 90 degrees apart.  In my experience when it works well on speakers it to work well on headphones too. 

Michael Williams expanded the Stereo Zoom to recording setups with multiple microphones played back on speakers which are not all equally spaced at 60 degrees and the same principles work.  (see the MMAD- Multi Microphone Array Design cross linked PDF chart pages on his website, and the AES papers there for details)

The basic aspect of Stereo Zoom is controlling the Stereo Recording Angle, which is the recorded angle as seen from the microphone position which is reproduced between the speakers.  What we call the DIN setup has an SRA of (+/- 50 degrees) 100 degrees total.  That means sound sources arriving through an imaginary window in front of the microphones which is 100 degrees wide will fill the space between speakers, regardless of the speaker spacing.   All the mic angle and spacing combinations in the table I posted above attempt to achieve a similar SRA of about 100 degrees.  Sounds arriving through that 100 degree wide window will fill the space between the speakers.  What the table lets you do is more or less keep that DIN recording angle unchanged, while repointing the mics the way you want them.

[F.O.Bean]

I run active bars in good venues and spots and when in shitty spots I run hypers/PAS, PERIOD!

[Todd R]

So, when I started this thread, one of the things I was curious to ask people about is, why do people spend thousands of dollars on schoeps mics with active cables, then instead of going for the best IMHO sound, go for convenience of a standard configuration when the mics might be pointing at the walls of a boomy venue when a narrower config is called for.  I mean, if convenience is your thing, I agree nothing beats the bars, but I don't particularly understand the logic...at least not when you've invested alot for top quality sound.  It seems kinda counterproductive if getting the top sound is your priority.

For me, I reject the basic premise you're working off of, so it doesn't seem like a disconnect.

With the exception of some of the latest active cable offerings, when you're spending thousands of dollars on active cable mics, you're not spending money on the best sound, you're spending it on convenience of set up and low profile. You can get the same mics for less without active cables or potentially could get better mics if you didn't keep the requirement of active cables. I realize there are lots of ways of spending lots of money on your rig, but the mounting bars really seem to be connected directly to those tapers who use active cable mics. And the choice of actives (particularly for open tapers and not stealthers) to me is largely a choice of convenience and not maximizing sound quality vs price, since the non-active versions sound the same and are cheaper.

So to me it isn't a surprise that someone who spent money on active cable mics puts a premium on convenience, and it then isn't a surprise that the same person wants the convenience of standard mounting bars. Convenience and ease of setup, size of gear bag, etc are very high on my list these days, and are probably more important to me than sound. And I like the convenience of mounting bars, though I don't use them exclusively. If I wanted best sound, I'd probably be dragging around a V3 and an AD2k or Mytek. Instead, an Aerco and an M10 seems much better.

[Todd R]

I'm not sure I understand either the question or the response, but just to try to clarify what I think I'm reading, the Stereo Zoom concept is about stereo imaging produced by two directional microphones.  In that respect, it's all about what we're trying to achieve at the point of capture in mic'ing up a room, and most rooms have PA speakers on the stage of a venue...it's about reproduction the sound imaging experienced in the room as closely as possible by those two microphones.  (For example, if you're facing the stage and straight ahead is considered 12 noon, if the drums are physically located on stage at 10 oclock, you'd ideally like them to sound like they're at 10 oclock on your recording...but if you don't use the correct SRA and spacing, they might sound in the recording as if they were located at 9 oclock or 11 oclock.)

Sorry Steve, disagreeing with you alot here, but the value to me with the SZ info isn't about reproducing a particular stereo image, but rather understanding generally how your recording ange and capsule spacing relate to the stereo image reproduced.

I actually don't lean towards the archivist stance, and instead want to produce a recording I enjoy. So if the actual stereo spread of instruments as panned and reproduced by the PA only goes from about 11-1, or worse 11:30-12:30, I might want to manipulate the stereo image I record so that on playback it sounds like an image extending from 10-2.

Lee already has got a lot of good feedback in this thread, including my bit above that the SZ concept is about exercising control over the stereo image.

He also mentioned something that is very important to me:  that is, if you want to get more towards PAS and hence are using a smaller included angle, you should then increase your capsule spacing.

For years, one of my favorite configuration is a wider spacing, like 12 inches (NOS spacing), and an angle of 65-75 degrees. I really keep hoping one of the mounting bar folks will make this as an offered product -- 12 inch spacing and 70 degree angle. This is often a great pattern for what we do.

[noahbickart]

I think this discussion should also encourage folks to think about M/S.

The convenience is unmatched, setup is simple, and the angle can be changed in post.

To those who have multiple schoeps caps already, a mk6 or mk8 adds a whole bunch of options.

[stevetoney]

Sorry Steve, disagreeing with you alot here, but the value to me with the SZ info isn't about reproducing a particular stereo image, but rather understanding generally how your recording ange and capsule spacing relate to the stereo image reproduced.

It's OK, Todd.

My comments are just my thoughts and the purpose of this thread was to solicit feedback and discussion from people on how they see things.  My thoughts are formed by the perceptions I have when I go out and record in the field, but rarely have those perceptions got hard core factual validation, like you'd get in controlled lab experiments, so I can still learn and I'm not so vested in an opinion that I have to prove myself right for the sake of being right (which unfortunately too many people here do).  Besides it's just fun to talk about this stuff and learn what others think on certain subjects. 

BTW, I'm on board with your comment about the general value of the SZ article.  We've talked about that before and there general conclusion was that you can break that article down and get really technical about it, but in the end the big picture takeaways are this general understanding about spacing and angles that you speak of.

[Todd R]

No worries Steve, I just didn't want to come off as too much of a contrarian.

I will say, the mic angle thing is the one thing that makes me miss my Milabs, and it has always made me wonder why so many Milab owners complained about mounting options. 

A short delrin riser tying together the supplied Milab mounts and put into a shockmount ended up just as easy and convenient as a kwon-bar setup.  And the forks of the milab mounts swivel, easily allowing you to change the mic angle.  This gave the ease and convenience of a mounting bar setup, but allowed different mic angles to be used.  I was able to score a few different delrin bars with the threaded studs, allowing DIN, a 9-10" spacing, and a 12" NOS spacing.  With the option to change mic angles, this was really versatile and easy.

[stevetoney]

I will say, the mic angle thing is the one thing that makes me miss my Milabs, and it has always made me wonder why so many Milab owners complained about mounting options. 

Honestly, that was another thing I had in mind in the Orig Post.  I was kinda thinking that, judging by the number of unfulfilled ISOs in the YS, since it seems some new active owners are stuck not finding bars for their new actives, that they might want to consider that the fixed bar option isn't the only way to go.

[Chuck]

For years, one of my favorite configuration is a wider spacing, like 12 inches (NOS spacing), and an angle of 65-75 degrees. I really keep hoping one of the mounting bar folks will make this as an offered product -- 12 inch spacing and 70 degree angle. This is often a great pattern for what we do.

I use the wider spacing and smaller included angle in a couple of my local venues, when I run hyper-cardioids from farther back than I'd really like to be. I even carry around the SZ included angles/ distance apart chart with me, so if I'm confronted with a weird scenario I can adapt.

I came to a somewhat profound realization when preparing for the Colorado Furthur shows this week. I made a DINa bar to run my active CK-63's recently and then realized that I should make it adjustable, for just this very reason. For example. I'm more likely going to run the hypers 11" apart and with a smaller angle at the 1st Bank Center over the weekend instead of ~ 7 inches apart with a 90 degree angle. A typical DINa mount won't work for me in that situation... 

[Gutbucket]

In the past I thought about designing an articulating bar, with sliding mounts which rotate as they are extended in the appropriate relationship to automatically retain the same SRA across the entire adjustment range - eliminating the need for refering to the table, measuring, and all of that.  I'm sure it would be possible but probably overly costly to produce given the machining and moving parts required.  Never got around to working out the mechanism for it in CAD or on a cocktail napkin.

I do remember seeing a video of a powered bar, with linear motors and stepper rotation which adjusts spacing and angle by remote computer control- a robot factory looking thing that is way complex and costly. I was thinking more of a simple mechanical sliding ruler thing with some plastic gears and components.

[ScoobieKW]

While I don't use a mounting bar, I have found that more than half the time, I'm using a setup for a 60 degree SRA, but capsule choice varies. Even in the 60 degree case, that would be three mounting bars.

[DigiGal]

In the past I thought about designing an articulating bar, with sliding mounts which rotate as they are extended in the appropriate relationship to automatically retain the same SRA across the entire adjustment range - eliminating the need for refering to the table, measuring, and all of that.  I'm sure it would be possible but probably overly costly to produce given the machining and moving parts required.  Never got around to working out the mechanism for it in CAD or on a cocktail napkin.

I do remember seeing a video of a powered bar, with linear motors and stepper rotation which adjusts spacing and angle by remote computer control- a robot factory looking thing that is way complex and costly. I was thinking more of a simple mechanical sliding ruler thing with some plastic gears and components.

Probably this one...
STEREOBLADE MOTORIZED STEREO BAR (AB, XY, ORTF, NOS, DIN...)