Topic: Running more than 2 mics

[EmRR]

If I can get more than 1 or 2 mics up, it’s always some variation of MS, DMS, ambisonic/horizontal B-format as center coincident array and spaced omni’s, I’m generally in the 2 feet or less camp. I did about 4 feet once for lightning strikes, usually we don’t get that sort of directional bass that’s useful. Center coincident as my earlier pic, don’t be afraid to have multiple M options in a MS or DMS array, it’s really not hard to phase them properly, not unlike the Straus Paket approach for in between patterns. You can pre-build some parts so they’re ready to go up fast.

[vantheman]

Here’s a story about how running a 4 mic array got me out of a jam. I had been wanting to experiment with spaced omnis, and recently I recorded a rock trio with some big name guys in a very small room. It’s amazing they were so supportive of me wanting to record them - running on stage, close miking amps, access to multis, the whole ball of wax. I think I’ll be able to share it soon, I just can’t yet. Anyway, as I prepared for the show I had also been reading about these 3-4 mic arrays that some people here like, and decided to run my CM4s in XY in the middle, and the OM1s spaced a little over 2 feet.

When I got home and started to evaluate the material, I had fully expected to not need the center pair, after all it was just an experiment. But with the musicians positioned like this - guitar left, drums center, bass right, I quickly ran into the problem of having way too much bass on the right. It’s really fatiguing especially on headphones to have low frequencies coming out of only one side. I had to go down a big rabbit hole and really learn about how to manage bass in a mix. Dan Worrall helped. The bass ISO was helpful to a point, but on half the songs the bass player used an upright with gut strings, so the DI input was useless on those songs. So I was sitting on a stage mix that essentially sounded empty on the right.

Enter the XY pair. The more I brought them up in the mix, the more everything started to make sense. Bass started moving to the center, drums sounded crisper. It narrowed the mix quite a bit, but it’s basically how it would have sounded standing 15 feet from the stage, and certainly wider than a mono house mix. And it also helped to fill the hole I had on the right. So I really started embracing the XY pair in the mix. It didn’t solve my bass problem entirely but it helped a lot, and it gave me a really interesting, drums-forward sounding mix.

I actually want to revisit this show again and try to come up with a more omni-based mix, but as a result of this bass problem I developed a technique/workaround where I EQ the bass in mid side mode, cut the low frequencies on the side only, and that essentially solves the problem. Still experimenting with the right cutoff, I’ve been cutting it in the 260hz range on the sides. I recorded Dale Watson a couple weeks ago with just a pair on stage and had the same problem with the bass and the technique worked in that case too. In that case there were other things going on in the mix to make it sound not empty on the bass side.

Anyway, just a quick tale about how a center coincident pair saved me one night. Separately if anyone has thoughts on where the right ballpark cutoff might be with the above bass cutting technique please do share your thoughts. I have all sorts of ways to listen to full range music in my home but I don’t have any room treated for bass so I’m always guessing on it. I’ll also share that Dale Watson show in Kickdown shortly.

[morst]

As for the topic, David Griesinger-look him up. 

Did that. His site uses the word concha, which I found out is an anatomical part of the outer ear.
"Current hearing research models the concha and ear canal system as a simple tube. But it is in fact a sophisticated a form of ear trumpet that increases the sound pressure at the eardrum by 18dB (for the author) at ~3kHz."

https://elementsofmorphology.nih.gov/anatomy-ear.shtml

I’ll also share that Dale Watson show in Kickdown shortly.

I was surprised to find out that Dale is on the LMA.
https://archive.org/details/DaleWatson

[Twenty8]

Best part about media?  You can turn it off/change the channel/etc at any time you choose.  I like and tend to read long posts.  I tend to absorb more information than I use in relation, but this is also my joy.

As a beginning taper (5 years), I nearly always run 4 channels.  What my experiences in the field/reading TS have led me to post-pandemic is: still recording 4 channels.  However, I now prefer the sound of each pair individually rather than mixing them at varying levels together.  Reading this board, deciding what was right for me, listening and processing and listening more.  This repeated pattern has helped me realize exactly what DSatz is saying.  Generally, each pair stands on their own better and only about 20% of the time (with phasing adjustments and some post-processing treats) does the matrix really shine above one of the pairs on their own.  I still like the sound, but over the last year have been leaning more on passing forward what pair I feel sounds the best (or both pairs separately).   It took some time for me to run 4 channels, but it has also taken a lot of time and experience to understand running 4 channels.  I feel like I really enjoy the process more now that I don't think each night "I hope the matrix sounds good."  I now enjoy what I am learning and best-practice with a small footprint.

I generally run DIN or DINa with NOS.  Still do most of the time.  I am now experimenting with just a pair in ORTF with subcards or cards and am building an even lower-profile rig to do this in varying capacities around town (think Royal St corner bands).  Reading dense-thread TS, practicing, listening... This is what keeps me going in a hobby.

Don't stop posting at length.  If I don't want to read it, I won't.

[wforwumbo]

I am of the opinion that the only wrong way to live one's life is to insist that others are wrong, especially if I insist I'm right. I tend to take everything with a grain of salt until I've had a chance to knock on theory AND practice quite a bit myself, and understand the benefits or shortcomings of whatever I am actively trying to do. Noah, Gutbucket, and DSatz have all given me more endless practical knowledge that I know what to do with, and I've been spending at least the past 5+ years of my life collectively unpacking their wisdom and trying it for myself.

I tend to run 3 pairs these days because I can. When it's inconvenient for me to run that third pair OR if I'm in a situation where I don't think the third pair will give me any great benefit, I only run two pairs. I never run one pair on its own, it's always "easy enough" for me to run the second pair and get a different recording to experiment with and turn taping into a science laboratory.

There are two extremes of stereo microphone techniques: coincident microphones (XY, Mid-Side, ambisonics) and spaced AB pairs. These two extremes correlate with the two most well known (but by no means complete, exhaustive, or universal) binaural cues that we use for localization and perception of sound in space: the difference in level cue, and the difference in time cue.

The idea behind the "classic" stereo near-coincident techniques such as ORTF, DIN, NOS, etc is to get a blend of these two cues in a manner that the engineer designing them finds both pleasant to listen to on playback, and accurate for depicting the acoustic field that the microphones captured. We use them as a template, and I now notice a larger number of tapers going "off script" when we find techniques we enjoy better - I personally prefer the bass response and increased time cue of NOS's wider spacing, but narrow the mic angle to get more of the image "in front" of my recording and to get closer to on-axis with the stacks when taping.

I echo Gutbucket's sentiments that many tapers likely shy away from multi mic techniques because it's possible to get into trouble pretty quickly - not just from combs, but from phase misalignment. Trying to mix two near-coincident pairs is difficult to get right in my experience, but that's not to say one can't get reliably pleasant results with it - just that it's a problem I haven't figured out and haven't bothered trying to solve.

For multi mic pairs, I have had the most success running AB Omnis or sub cards, and mid-side or XY pairs between them, then mixing down in post. You can stream the results of this method using 60cm AB mk21s and a mk4/mk8 mid-side pair here: http://phish.in/2019-08-30 if I use my Omnis today for the AB pair and add a third pair of hypers, cardioids, or subcards in a classic near-coincident technique for consistency and because I like the results, I'm at 3 pairs right there. Given I own 4 pairs of microphones, I've been thinking long-term about switching to a deck that can run all 4 pairs when I want to... but time and my finances will dictate if I ever get around to that.

While the basic concept of comb filtering is straightforward enough, we are still receiving many, many, many combs from a variety of sources. As the pinna (outer earlobe) and concha (inner bowl surrounding your ear canal) serve to funnel sound, they also serve to provide a quick reflection off a certain point of your ear, and this contributes strongly to your sense of elevation or height of an audio source. Likewise, there is a comb between your left and right ear in the free field, not to mention all of the combs that are a result of arriving specular reflections in any acoustic space with a boundary capable of reflecting sound. David Griesinger is a close friend, and former mentor and boss of mine - he's a wonderful and smart individual. I've discussed live music taping with him a number of times, he thinks we are simultaneously noble and crazy for attempting to record amplified pop music in a noisy crowd. He himself is an extremely accomplished classical recording engineer, and his go-tos are binaural microphones for recordings he makes in Boston Symphony Hall; when he hangs main pairs, he's a big fan of hypercardioid SDCs in ORTF-ish, though he doesn't do that any more the last I spoke with him.

[Derp1]

6-8 channels on stage seems to sound pretty good most times.

[DSatz]

dyneq wrote:

> It's about time you showed up with your pedantic drivel! (how's that?) ;^)

Many thanks. We're good now.

> What are some examples of past and present microphones that have a fuller low-frequency response at greater distances? Are there aspects of their design and construction that they have in common to achieve it?

Well, I was talking specifically about directional (pressure gradient) microphones, since those can have flat response to low frequencies EITHER for close miking OR for more distant miking, but never both. That mutual exclusivity doesn't occur with single-diaphragm omni microphones that function as pressure transducers, but it does with all other directional patterns. In fact, a supercardioid or hypercardioid will have this characteristic even more than a standard cardioid, all other things being equal (i.e. the amount of proximity effect will be greater).

And I'm saying that if you're looking at the description of a particular product and you notice that the words and pictures all show close placement (e.g. being attached to musical instruments) then chances are, it was designed specifically for close miking and will be relatively thin sounding when used for more general recording. Sometimes the manufacturer or dealer will list the recommended applications for a given type of mike--again, if it's designed for communications or speech, then be warned.

Even when specifications and curves accompany the verbal description, the trend nowadays is for the manufacturer to set the measuring distance according to the intended application for the microphone. They don't usually tell you when they've done this, however. The same manufacturer could use 1 meter measuring distance for their "flagship" microphones (say, for classical music recording) and 30 or even 15 cm for microphones intended for close placement, e.g. to solo instruments or voices.

Take for example Audio-Technica, a company that makes really good microphones in my opinion. The mikes that they design for close placement are measured up close, whereas the mikes that they design for more distant placement are measured at a greater distance. So their response graphs all look as if they will offer well-balanced low-frequency response, and indeed they do--WHEN used at the intended miking distance for the particular model! But if you take a directional microphone that was designed to be clamped to the bell of a saxophone, say, and you use it for recording stuff that's 25 feet away ... you won't get the advertised low frequency response, maybe even by 10 - 12 dB (say at 50 or 100 Hz).

On a technical level, adapting the design of a more general-purpose directional capsule for close speech pickup can involve increasing its membrane tension. But that's not a parameter that the manufacturers publish, so it's not something that you can go looking for!

[kuba e]

DSatz, thank you for the explanation. I have a question. When the directional microphone is not suitable for distant recording, can we fix lower bass with eq? Probably the eq will increase a noise in the low frequencies. We are not so sensitive to the low frequency noise. That noise could be covered by the higher background of our audience recordings. I looked, background audience noise in recordings is from 200-300hz and above. I had a couple of audience recordings that had very weak bass. When I fixed it with eq, sometimes even +12db, they were good. I understand that it is better to record correctly from the beginning than to repair it amateurishly. Eq is not a clean solution, but is there anything else besides the noise that we should watch out for?

But with the musicians positioned like this - guitar left, drums center, bass right, I quickly ran into the problem of having way too much bass on the right. It’s really fatiguing especially on headphones to have low frequencies coming out of only one side. I had to go down a big rabbit hole and really learn about how to manage bass in a mix.

I like onstage recordings and I don't mind if the bass (or drums) are on one side.  This is normal for onstage recording. If you recorded with xy, definitely try mid/side ratio and mid/side eq. Be careful when reducing the bass in side, sometimes spatiality can be lost. Also read a tread in the link below. There are interesting posts, maybe some of it will work for you (you can try free PhaseBug vst plugin, i don't know if it's good but i tried it couple times and it works).
https://taperssection.com/index.php?topic=201100.15

[DSatz]

kuba e, yes--that kind of thing is exactly why EQ exists. And honestly I think that many people's aversion to it is -- well, I just think that maybe they could use an occasional walk on the wild side. The important thing is to sin in moderation, especially if you're just starting out on the road to hell. A recording that (objectively measured) is somewhat bass-deficient compared to the original sound in the performance space can still sound quite good, especially if the original sound was artificially "boomy". That happens pretty often. Plus people's playback systems and listening rooms usually have various bumps at low frequencies.

So it's not always a blessing to record with microphones that have absolutely flat low-frequency response. You just have to get "into the ballpark" and get a reasonable balance of the bass with everything else. Clinical correctness never won anyone a Grammy award.

[grawk]

My experience is that almost every live recording sounds better with a little less bass than was in the room, unless you're going to be listening to it in a room filled with people at concert level volumes.

[JiB97]

kuba e, yes--that kind of thing is exactly why EQ exists. And honestly I think that many people's aversion to it is -- well, I just think that maybe they could use an occasional walk on the wild side. The important thing is to sin in moderation, especially if you're just starting out on the road to hell. A recording that (objectively measured) is somewhat bass-deficient compared to the original sound in the performance space can still sound quite good, especially if the original sound was artificially "boomy". That happens pretty often. Plus people's playback systems and listening rooms usually have various bumps at low frequencies.

So it's not always a blessing to record with microphones that have absolutely flat low-frequency response. You just have to get "into the ballpark" and get a reasonable balance of the bass with everything else. Clinical correctness never won anyone a Grammy award.

Personally, I seem to have a hang up on doing EQ for a few reasons on my recordings:

• I use Audacity which I find great for most things but lacking in this area
• Applying EQ to a full recording takes a while and is resource intensive
• I don't have any training in really what I am doing with EQ besides a basic grasp of the 20hz-20khz range and what I think sounds OK
• As such, I feel I will cause more harm than help in the long run
• I mainly edit and listen to my recordings on my home stereo and not on ear/headphones
• Mostly, I guess I would rather leave it up to the listener to decide their on EQ settings

I also feel like I would go down a rabbit hole of tweaking things and working to get it "just exactly perfect" if I were to have EQ be part of my processing workflow. More often than not, if I run a 4 channel mix with the intention of actually using all 4 channels in the final mixdown I will be running AKG ck8s with a pair of AT u853r omnis. The omnis help to round out the low end if the bass is somewhat lacking in the AKG pair when listened to on it's own, whereas the omni pair can sometimes be a little less detailed than I normally like when played back by itself. I have found doing a mix of the two stereo pairs where I keep the AT omni source around 6-8 dBs lower than the AKG pair seems to work well without sounding too cluttered for my liking. YMMV.

[vantheman]

I’m sort of in the same boat with EQ and I’m taking it slow. Audacity is great for some things but the world opened up for me when I started using Reaper, especially when I have more than 2 tracks. The UI is better for things like EQ. I mostly use EQ to tame the bass. I have Ozone 9, and to practice EQ I’m getting into the habit of running through their mastering presets which gives me a sense of how things could sound with a wide variety of curves. For example I can look at the curve on their “reduce mud” preset, and then i can go back into Reaper and fine tune my own curve. But I find that a many of their presets will sound good on a particular recording, so I’m starting to realize how much of EQ is about stylistic choices.

[morst]

I’m sort of in the same boat with EQ and I’m taking it slow. Audacity is great for some things but the world opened up for me when I started using Reaper, especially when I have more than 2 tracks. The UI is better for things like EQ. I mostly use EQ to tame the bass. I have Ozone 9, and to practice EQ I’m getting into the habit of running through their mastering presets which gives me a sense of how things could sound with a wide variety of curves. For example I can look at the curve on their “reduce mud” preset, and then i can go back into Reaper and fine tune my own curve. But I find that a many of their presets will sound good on a particular recording, so I’m starting to realize how much of EQ is about stylistic choices.

I use audacity ALL THE TIME I mean daily like EVERY DAY and I just tried to use an EQ on a small section of a track where I wanted to just bring midrange through so I could hear lyrics of one song.
Audacity is SO ANNOYING with respect to plugins. very impractical (I am using V 2.4.2 'cause of all the stuff about how v3+ "phones home"




ugh. Sony Soundforge 2015 for mac is WAY nicer for the plug in interface, even considering how often the old thing crashes!!!

[fireonshakedwnstreet]

The new Audacity is great for plugins with the real-time non-destructive functionality. I still do my basic cleanup on Audacity and master through Reaper. For anyone a little lost on EQ, you can use a reference track of a recording you know well and like to try and match the tonality. Just make sure they are normalized to the same loudness as your recording. You can then use an EQ plugin like TDR Nova. Very use to use. Lots of good info on YouTube too.

[Craig T]

You can then use an EQ plugin like TDR Nova.

I second this recommendation for Audacity users.  My go to.  And to bring it back on topic, for a recent recording I used 2 pairs of mics (cards and omnis) and used TDR Nova to apply complimentary HPF/LPF (200 Hz) to mix the two pairs together.  The mix was definitely better than either on their own.