Topic: Loud / Amplified shows: diminishing returns?

[Gutbucket]

No worries, its a good conversation.


"Taping a PA from front of house in an ORTF style or similar config, with mics spaced and angled reasonably and consistently (or the same) in all situations, sub cards or omnis will give you more reverberant response than supercards will."

That's right.  In that case, if constrained to that recording position and that microphone spacing and angle, by changing the microphones to a more directional response such as cardioid or supercardioid, you will increase the direct/reverberant ratio in the resulting recording and get more direct sound and less ambient room sound..  And you will also change the stereo imaging at the same time.

Do you really want to change both the direct/reveb ratio and imaging in that way? Simultaneously? Probably not.  It's far more likely that the choice is sort of made for you by your gear.  Perhaps you only have one mounting bar that provides an ORTF setup of 110 degrees at 17cm, and you can change to mics with a different polar pattern but not change the angle and spacing of them.  That kind of thing is common around TS. 

What would be more appropriate would be to also change the angle between microphones, or spacing between them, or both, when changing to a different polar pattern microphone.  That would allow you to maintain similar imaging, or adjust it independently.  That was my motivation for working up the "Improved PAS table" I posted here a number of years ago to help tapers who didn't care for figuring out all this theory stuff and just wanted to make a decent recording in a crappy situation.  It makes managing that spacing/angle/pattern relationship simple by reducing the variables to simply pointing supercardioids at the PA speakers and then determining what the appropriate spacing between microphone should be base on the resulting angle between them.


"It's definitely possible to get a wide imagine with a pair of narrow polar microphones, but wouldn't you start to lose your center at a point?"

Not necessarily, and not any more than using some other polar pattern instead.  It all depends on the other variables of the setup.  Could also get a weak center from an over-wide omni recording, which is probably more common.


.."cards or sub cards at a 90 degree angle from each other will have a wider perceived image than super cards at 90 degrees. There's not much of a point in recording a PA with supers or hypers facing 180 degrees away from each other"

Actually the opposite.  In terms of stereo imaging, with identical spacing between microphones, a pair of supercards at 90 degrees, will produce a wider playback image than a pair of cardioids or subcardioids.  If the recording position in the room is reasonably close enough, they will also pickup less room reverberance, which could possibly be described as sounding "narrower" but that's something different and mixing up two different aspects.

Some may find this hard to believe, but I record using supers and hypers facing 180 degrees from each other all the time.  Granted I also have another microphone in the center between them facing forward (and usually a fourth facing backwards), and that arrangement is which is what allows me to adjust the EQ and level of sound from each of those directions somewhat independently from each other.  They are still highly interdependent, but the degree of freedom it gives me is invaluable and a big part of what I was describing previously. 

And here's something about that which I found very interesting, which is totally relevant to this thread-
Even though I would never record with just a single pair of super/hypercards facing 180 degrees apart, and certainly not with the 2' to 3' spacing between them that I'm using when I also have the other mics combined with them in the same array, I found that when using excellent quality microphones with very well behaved polar responses in a good ambient position where the direct/reverberant ratio is correct for a pair of spaced omnis (outside in an amphitheater, FOB), when muting all the other channels and just listening to the pair of sideways facing super/hypers alone over a stereo pair of speakers it sounded very good.  Amazingly good.  I fully expected a huge hole in the middle.  I fully expected mostly ambience and muddy direct sound.  But instead it sounded totally acceptable.  I attribute that to two, maybe three things: The environment (the outdoor amphitheater and the direct/reverberant ratio at my recording position in it); the very well behaved polar response of the excellent microphones I was using, even far off-axis; and perhaps the nature of recording a large PA (I was centered, and as is typical much of the mix was mono, and that probably allowed the over-wide spacing to work without too much 'hole in the middle' similarly to how very wide spaced omnis can work in the same situation without too much 'hole', even when that would not work in other situations.  Recording a mono-ish mix produced over a wide spaced pair of PA speakers, from the distances we are commonly doing it, is not a normal recording situation in any acoustic situation other than live concert tapers.  Yeah I know that doing that is typical around here, but it's a totally freak oddity in the recording world really).

[opsopcopolis]

Interesting.  Thanks for the info!  Only thing I would clarify is that with the 180 degrees comment I did in fact mean only those two mics. I totally understand the use of that spacing with a middle and backwards facing mic, just not something I would ever think to try on it's own. 

With that last scenario, my question then becomes, is that a good aspect for a mic to have?  Do you want supers to have such good off-axis response that it almost sounds on-axis or does that sort of defeat the purpose of having such a narrow polar pattern.  (please excuse if that's a dumb question)  I guess it would depend on the setting

[chk]

I think there's some truth to what you say, in this general sense: Obviously, an amplified PA system recorded at a distance does not have much in the way of detail or frequency response (except in the low-bass). So, obviously, a high-end condenser microphone cannot pick up more than what is there. But, as others have already pointed out, there's still the matter of the overall accuracy of the microphone at recording whatever IS there, and I think the preference for certain high-end condenser microphones around here goes beyond just some kind of snobbishness about what they've cost. I've owned and used most of the brands, and I think that the person who originally recommended Schoeps to me was right -- they're "good at recording PA systems." Is there less difference between an amplified rock show recorded with Schoeps vs. AT 853s compared to a symphony orchestra recorded with those two brands? Maybe/probably. But the difference is still there.

I personally think the more steep diminishing returns are experienced in the preamps and A/D stages. First of all, I'm not convinced that the A/D of any prosumer or better machine is really improved upon much by an outboard. Even with preamps, I know we all have preferences for "flavors" of sound, but I think you're really entering speculative territory there. You can run a comp and tell a difference, but it's not clear to me that the "difference" is significant enough to warrant the use of that equipment.

Conversely, it's not hard to tell the difference in a Schoeps recording, a Church Audio recording, and an internal mics recording. That doesn't mean everyone will always prefer the most expensive one (especially without EQ), but the differences in the recordings are very, very obvious.

What he said!

[Gutbucket]

Do you want supers to have such good off-axis response that it almost sounds on-axis or does that sort of defeat the purpose of having such a narrow polar pattern.  (please excuse if that's a dumb question)  I guess it would depend on the setting

Not a dumb question at all.  I've also wondered if an identical frequency response both on and far off-axis, with only a difference in level, is always the appropriate ideal. My thought is that in some cases a "loudness-shaped" frequency response may be appropriate as the level drops off axis.  And that's what I've never gotten a good answer for.

But the same frequency response in all directions, only differing in level is the traditional goal, and probably the most appropriate one in most cases.  It's difficult to achieve though, and only a few high quality manufacturers can really approach that ideal for super/hypercardioids.  It's somewhat easier to find at the polar extremes with figure-8's and miniature omnis.   It's one reason the Schoeps MK41 supercardioid is highly revered. 


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The odd array I'm using with 180 degree opposed supercardioids is a variation on Günther Theile's 3-channel OCT array (Optimum Cardioid Triangle) which uses one forward facing cardioid as a center microphone and two supercardioids facing directly to either side as left and right microphones.  The idea is good imaging via ideal overlap between each side and center, yet with minimum possible cross-talk between left and right channels since the null of the left supercardioid points at the right edge of the stage and vice versa.  Since those mics are oriented 90-degrees away from the stage, the quality of the pattern from about 30-degrees across to the supercarioid null at around 130-degress off-axis is where all the "main stuff" is happening up front, and he specifically calls for using Schoeps MK41 supercards for those left/right channels because of their excellent pattern behavior that far off-axis.  I'm primarily using Microtech Gefell supercards for this which are in a similar class and also have very good pattern behavior, and mostly use this outdoors.  (image below is from the Schoeps site, at the page linked above)

[opsopcopolis]

Thanks for the info. It's an interesting setup and the use of supers like that makes total sense when you see it in context

[bombdiggity]

Come back a bit later and we're way far along but:

bomdiggitty- your response to my question about your preference of straight SBD or good matrix, tells me that you do prefer some degree of ambience in a live recording.  In other words, it establishes that your preference is not for a recording with a direct/reverberant ratio of 100:0.  The next question then becomes what is the preferred ratio?  ..and that answer is going to be different depending on a number of things.  What I'm taking about above is partly making that ambient/reverberant stuff sound as good and natural as possible, regardless of it's most appropriate level.  By making that stuff sound as natural as possible the undesirable stuff actually becomes slightly less offensive to my ear, at least in the sense of getting lost in the recording rather than hearing it's flaws.  A natural sounding recording of crap (idiots talking) is at least natural sounding and the recording itself doesn't also distract me.  If it's unnatural and muffled I still hear the idiots talking AND the recording of it sounds like crap, and destroys the illusion for me.  Since I can't totally eliminate the crap I don't want, I can at least make it natural and that actually allows me to tolerate a somewhat higher ratio of it.  I know the pain, I know it all too well, believe that.

I like some degree of ambiance but suspect I like less than many people desire.  Obviously from a scientific perspective reverberance is a great deal of what provides ambiance but IMO it doesn't take much reverberance to provide ample ambiance.  Frankly I've never tried the far more ambitious multi-mic ideas mixing various patterns and working off the nulls or mixing multiple mics in post, etc.  I don't think I have enough gear or opportunities to experiment (where if it abjectly failed it wouldn't matter to me). 

I like a higher proportion of direct than reverberant sound.  I don't think that most people realize how short the distance is in most rooms where that ratio favors reverberant.  A PA places one at a distinct disadvantage in this calculus since one tends to need some distance to capture a balanced representation of the output, especially where the room sound is a mix of stage and PA point sources.  House imposed limitations on placement (such as open pits, fronts of - or worse under - balconies, around the board, back of room) may put one even further back.  1:1 direct:reverberant happens very quickly.  Mid to back of room is going to be weighted far toward reverberant, though bodies will soak some of the reflections up. 

Outdoors is much better in terms of limiting reflections but that tends to add the "idiots in the crowd" factor since people tend to feel much less compulsion to be attentive to the music in those settings. 

Either way I like a directional mic that will pick up more of the direct sound I want (which seems the simplest approach to it, though it could also be simplistic I suppose), though I do see your point about getting a more natural ambiance when one has no choice but to capture said ambiance.  Thankfully I rarely go to shows where that sort of thing is the norm.  There are a few instances where clubs are chatty.  In those I strongly prefer stagelip where most of that chatter is well behind the mics and with good mics therefore at a very low level relative to the music than I do having the distractions recorded fully and naturally.  A few places or particular shows where the distracting elements are too intrusive I just don't go in the future and/or the recording winds up mothballed unedited. 

Contrary to either of our preferences (with the above said) some people do like a more extreme sense of being in the crowd and actually seem to like the muddy internal mic back of the hall sound since that's what it always sounds like to them when they see something (on the far upper deck of their local arena with a bunch of screaming idiots).  They know no different...  That's not the TS crowd, though may be the oft-maligned run of the mill at certain torrent sites... 

[bombdiggity]

The ratio of direct sound to reverberant sound in a recording is not primarily due to the polar pattern of the microphone used. It is predominantly a factor of the distance of the microphone(s) from the sound source, regardless of polar pattern.  Polar pattern is only a secondary factor.   

This. 

Though IMO choice of polar pattern can emphasize or minimize some aspects that accompany the distance. 

[Gutbucket]

..distractions recorded fully and naturally. A few places or particular shows where the distracting elements are too intrusive I just don't go in the future and/or the recording winds up mothballed unedited.

What I'm advocating for isn't those distractions recorded fully AND naturally, but rather achieving as much minimization of those distractions as possible within the limits of them still sounding natural.  If I can only reduce that stuff further by making it sound less transparent and natural, that's where I draw the line.  When it get to balancing the good ambience against the bad ambience, therein lies some of the art of the craft.  I hear you on the places and shows where it is really bad, and just don't record that stuff or in those places anymore.  Yeah, I've become even more of a quality snob over time, but life is short and shitty recordings numerous. 

And yeah, the critical distance (where the D/R ratio in the room is 50/50) is usually absurdly close to the on-stage source.  Stage-lip may be close enough to achieve that in a large room.  PA's can actually help move the critical distance a bit farther away that since they are intentionally directional, and don't illuminate the room equally, as long as you don't care about getting the actual stage-sound too.  That's one reason I like small front audience fills, either along the front of the stage, or cross-firing from either side of the stage to a point at the stagelip, both of which can provide some good, direct PA-mix to a stage-lip mic arrangement, without swamping the on-stage sound due the lower-level of those fills vs the big PA stacks.

Given your preferences, when you find you can't setup stagelip, you should strongly consider PAS with supers/hypers to maximize your D/R ratio as much as possible, with enough spacing between mics to make up for the minimal PAS angle which will otherwise produce a mono-ich, collapsed, center heavy soundstage.