Matching mic setup to specific room conditions?

[jnorman]

i, like many, often find myself in unfamiliar spaces with no chance to audition a variety of mic placements to determine best mic placement for a given room, and wind up guessing the best i can and taking my chances - i never have the leisure of isolated monitoring. so, i also often find back in the studio that i should have done something different given the amount or lack of natural reverb, etc.

1. how do you go about matching mic placement to a given room, or do you pretty much use the same setup no matter where you are?
2. when in a dead space, how do you mic differently from a live room?
3. do you mic differently in a medium sized studio than you would in a large auditorium? (ie, mics further back, closer, wider spacing, whatever)
4. do you treat certain instruments differently than others? for example, i find that i can track a violin in the studio, mic about 3 feet out, add some digi-verb, and get a very realistic result, but i simply cannot make a flute sound good like that at all. and while i can start getting a good flute sound with mics out at 7-8 feet, an accompanying pedal harp is muffled and indistinct, and i must add in closer mics for the harp. etc, etc...

any general guidance you might be able to give me would be much appreciated. thanks.

[joelpatterson]

I am always winging it. I just trust that my instincts won't lead me astray. In my mind, you can describe mics as "good for close-up stuff" (tube mics, dynamics) or "good for distance stuff" (ribbons, SDCs.) These are maybe clumsy, broad-brush ways to look at it... not strictly true in every single case... but good starting points.

If you're trying to record a soloist, you get a mic somewhere within a few feet of them. If you're trying to record an ensemble, you "ring" the soundfield with sets of stereo mics-- you imagine that the orchestra is lodged inside a giant fishbowl, and then you place mics at equal intervals around the surface of the fishbowl.

In general, you will end up with lackluster recordings when the mics are too far away from the subjects.

It's all about experience, seeing what works, and more importantly, seeing what doesn't work, and the only way to learn this is by making a few, well-timed, ghastly mistakes. This-- I believe.

[mohthom]

Knowing how instruments work, act and react is key. Understanding the way that a bassoon will sound in a cathedral as opposed to a studio theatre cannot be put into words - it's one that you have to experience. The best way to do this is to play or watch groups in these sorts of varied acoustics and learn the positives and the pitfalls of each instrument/acoustic combo. Learning what to expect from a venue is also a key skill - I've seen top professionals get it badly wrong (no names mentioned!) and wreak havoc on the results of the sessions. That said if you've got a good sounding venue, use it - mic from further away etc..

I can use the same microphone setup (in different arrays, sizes and shapes) to achieve good results in most venues, but the ability to change/add/remove microphones from the setup is useful. While many on these boards may consider it unmanly, I have been known to put up more than one main array (and remove the one deemed superfluous before showtime) when time constraints have been tight.

Don't feel that a microphone on the flute (your example) has to represent the full range of the instrument, or that it has to be high in the mix. I like to leave the performers to balance themselves (like musicians . . . ) and use spots very low in the mix for clarity purposes only - on a recent session I spotted a singer and cut off everything below 2khz because I just wanted the detail, not the body of the sound. Too many spots just means a difficult mix with often confused results. Maybe my lack of experience doing this (I simply don't think it works that well for me, so why bother honing the art?) could be a culprit, but I doubt it.

BTW with the harp, if it sounds muffled and indistinct with lack of sustain or volume it's often - counterintuitively - the bass wires causing this problem. They may need replacing (roughly once every 12-18 months for a professional player) - not a cheap job!

Ears tell you what a position sounds like. Experience tells you what a microphone sounds like. Confident delivery of the master CD tells the client what the result sounds like! Balance the three for perfect results!

MohThoM

[jnorman]

thanks joel and moh - some good thoughts there.

joel - in general, i sort of agree with your close mic approach, and it often works quite well, as with strings, piano, voice, some other things - but - close micing just does not seem to work well with some things, specifically for me, the flute. i guess it is somewhat like the purists who wont record a classical piano closer than 10 feet - i just feel like you cannot capture a realistic flute sound closer than 5-7 feet away. and when i mic a flute like that, i cant very well track the piano from 2 feet away and make them sound like an ensemble.

OTOH, i can mic a violin at 2 feet and close mic a piano and mix them pretty well. i have no idea why flute seems so different to me than almost anything else. i did some recordings of a flute/pedal harp duo where the harp is right in your face and the flute is like 6 feet behind the harp, and for the life of me could not figure out how to fix that - i could not get a flute sound i liked when i close miced it, and i could not get a harp sound i liked if i didnt close mic it...

thats part of why i posted this question.

[mohthom]

I gotta ask . . . where are you placing the flute mic? I don't find the flute too problematic - I want to know why you do!

MohThoM

[joelpatterson]

Me too, I did a girl's school jazz band thing once where oddly enough the flute was one of the major soloists. I had her step up to an M-9 (those were the days!) and it came through amazingly clearly-- I'm sure the room mics helped with rounding out the sound, but it got what we were all after, a clearly defined flute sound that captured all the swoops and trills just right.

[Corran]

As a flutist, I am constantly trying to get a "perfect" flute recording. The best results I've had were always in a concert hall, with a distant and a close (3-4 feet) mic. I recently recorded my flute professor (amazing player) playing a concerto with our orchestra. I put an Oktava 012 about 5 feet away, at her knee's height pointing up. It added just the perfect amount of "presence" to the recording.

As for the question, I always try to get at least 2 pairs up in an unknown situation so I have options (an ORTF and A-B usually). It is troublesome sometimes. And joel's right - you will make a few mistakes. I recently recorded a horn recital at a church awful acoustics - sounded awful too. I ended up just doubling my center mic, panned L and R in a psuedo-stereo thing. I hate it. But oh well.

[David Rick]

Here's how I think of it:

The room/hall is something I can't control. Since I can't control it, I need to adapt to it. In doing that, it's helpful to have as many degrees of freedom as possible. Let's make a list:

• Distance from stage front
• Height of stand
• Spacing between microphones
• Angle between microphones (or baffle size)
• Microphone pattern
• Microphone choice
• Ambience mics
• Spot mics

If I start out by saying "I'm going to use this technique" (e.g. ORTF) or "I'm only going to use this pair of mics" (e.g. omni's), then I'm limiting my degrees of freedom and there's a higher likelihood I'll lose the battle.

When I walk into a new room, the first thing I do is wander around with a finger stuck in one ear, and try to find someplace (any place!) that the player or ensemble sounds good. If I can't, I know I'm in for a rough night, and it's gonna take a lot of mics. But if I can, then I say "This is the spot! What will it take to make a good stereo recording from here?" That's when it's helpful to have a lot of stereo mic techniques to choose from (see Williams), because the included angle to the stage is fixed and you need to come up with a mic array that matches it. If there are several options, then you can choose the one that works with the mics you'd prefer to use in that situation.

If I can get the same working angle using omni's and hypercardioids, I may prefer the former on piano and the latter on strings. But that choice also affects image distortion and where the room reverberance ends up in the stereo image. Some techniques pull the players toward the sides, and some dump most of the reverberance in the center. In the latter case, I might want an auxiliary spaced pair for better immersion, and I'll need the main pair to be dryer (closer) to make that work.

Now comes tweaking. Raising or lowering the stand changes the sound, usually in several ways simultaneously. The higher the stand, the more compressed the ensemble will seem from front to back. If the piano in a chamber ensemble sounds muffled compared to the front players, chances are the stand is too low. But raising it will change the string sound too, for better or worse.

Some instruments always seem to call for spots, and some you never want to spot. A harp almost always needs something stuck up close to the sound board. A violin will drive you nuts if you do that. A double bass will require help in one room and not in another. It's all a matter of listening, and that's where having some kind of playback you can trust is a really big help. If you can't hear what you're doing, than it's often just the luck of the draw. Got extra channels? Plug mics into them and pray you don't have to use them.

David L. Rick
Seventh String Recording

[fifthcircle]

David pretty much hit the nail on the head...

I will almost always bring multiple sets of mics to gigs so that I can switch things out when I don't like what I hear. I will usually approach things with a look at the repertoire that is to be performed and knowing the gear that is available to me (from mic to pres to converters), make some basic choices about how I would like to approach things. That being said, especially in rooms that I don't know, I find that the inital approach may be close, but not quite what I am looking for. It may involve a change from Schoeps to Sennheiser or an ORTF pair to a stereo mic. It may mean changing my omni flanks by changing grids or adding balls. It just depends on the situation. For the complex gigs in rooms that I don't know, I'll come way over-prepared. I may not use anywhere near all the gear, but at least I have it just in case.

In the end, it comes down to what I hear and having the tools to make sure I'm covered. My favorite piece doesn't always work and that is why I leave myself choices.

--Ben

[joelpatterson]

My problem is that I don't ever get the chance to "try things out, swap this for that" or otherwise noodle around. Quite often, there isn't even a soundcheck. I'm recording a concert that starts at a certain time. I get there an hour beforehand, set up, and hit record when the conductor waltzes onstage to thunderous applause. The levels of this applause, and how it hits the mics, I guess you could say that's the soundcheck.

[newyorker42]

Originally Posted by David Rick

Here's how I think of it:

The room/hall is something I can't control. Since I can't control it, I need to adapt to it.
<snip>
David L. Rick
Seventh String Recording

David Rick! You are on a roll, man! Your last 3 or 4 posts have been some of the most informative and generous with knowledge that I've ever read on this forum.