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Ive have recorded a 35 voice choir with two spaced condensers with reasonable success (about 8 feet apart and about 10 feet back [due to space limitations I cant observe the 3to1 rule on the stage]) although I needed to add synthetic reverbs . Im recording them again this weekend and The actual church reverb is beautiful so my question to you is. I plan on using the O.R.T.F technique about 12ft (is that a good distance) back from the choir and then a coincident figure of eights another 10-15 back to capture the room reverb. Is this a pretty safe bet or can you recommend another approach ? Any help would be greatly appreciated

Comments

Cucco Tue, 03/29/2005 - 10:15

Hey Docvlak,

ORTF is a pretty good pattern for a medium to small chorus such as you're recording. Whether 12 feet back is good or not is virtually impossible for anyone here to judge as it is completely dependent on the exact size and shape of the room, the placement of musicians, etc. 12 feet is well within what's considered to be a reasonable distance, so it's not like you're way out of line.

I don't see the need however for the addition of the blumlein pair as an add-on. You could use this as your primary pair and you'll find that they pick up quite a bit of ambience - moreso than the ORTF. Combining the two is just asking for bad phasing and timing errors. If you were to use both pairs, I would suggest blumlein for up close and move the directional mics to the back of the hall, lower their level and time align - this would give you some decent reverb. Bear in mind though, that the rear lobes of the fig 8s will be opposite of your regular panning. This could be beneficial in that they could provide some level of uncorrelated reverb which helps in the overall effect of reverb in the first place. Don't use too much uncorrelated though, it will make things just sound funky.

In other words, keep your add-on reverb channels tame.

J.

FifthCircle Tue, 03/29/2005 - 15:25

3-1 rule... blah blah blah...

Put the mics where they sound good. If you like spaced omnis, then use spaced omnis, but don't put them 12 feet back because of some rule that nobody really knows what it means...

Really- the rule applies more to close micing than to area micing. Put the mics in a mid field (as opposed to near or far field) location for best sound. If you can't get far enough away, then raise the level and place them over the heads of the highest row and aim them down into the group.

If you need to add some verb, then add some verb... It ain't rocket surgery... :lol:

--Ben

ghellquist Tue, 03/29/2005 - 22:43

I think you should remember that the 3 to 1 rule is intended for when you want to have separate channels on different instruments. Such as when you want to have guitar on one channel and trumpet on another, and be able to mix them at will later. The idea is then to avoid spill into other mics that may create phase effects. In this case the 3 to 1 rule comes in handy as as rule of thumb for how to stay out of problems.

Stereo recording of this kind is something completely different. Here the whole purpose is to have both (or more) sources in both mics, and to use the phase and volume differences to give a stereo image of the sound. For stereo recording there are a number of well-tried techniques, and it pays to learn them and try them out first. But in recording there is only one absolute rule -- if it sounds good it is good. And even that rule depends on what the listenere wants to hear.

So what I do, and I exect most other people do the same, is to start by setting up in one known configuration and then tweak things to get the sound you search for. The more experience you have (I´m still a beginner) I would expect you to come closer to a good setup from the very start. But listening and moving things around a bit is the only way I know of to get at the sound.

Starting with ORTF using a pair of cardoid mics sounds like a good bet here. Set them up them in front of the choir. Things you may want to tweak are:
- closer or farther from the choir. Very much depending on the room acoustics. You will probably find that there are specific "spots" in the room where the sound is bad, and some where the sound is better.
- higher or lower. Can influence the balance between back and front rows.
- tilt of the mics. Tilt them down to get a bit more high frequencys, horisontal (or perhaps even slightly upwards) to get a bit less high frequencys.
- angle and distance between the mic. Mainly to influence the stereo image. Look at for example the DIN setup, a bit smaller angle and a bit further out.
- move the choir around a bit. Perhaps putting those very strong sopranos in the back row just for the recording, allowing those weak basses to step forward. Having them in a half circle instead of a straight line.
- moving around in the room. Perhaps right up to a wall. Perhaps in the middle of the room. Putting up some textiles or screens to change the sound of the room.

And of course, if you have different mics you could try them and start all of over the change process. And if you have different kinds of mics, perhaps a Blumlein or MS setup is better.

As you can see the variations are limitless. So what I tend to do is to think things through ahead and decide on one setup, say ORTF. Then move things around to get as good sound as I can.

If there is time, mark things up on the floor, give the singers a break, and try another setup, say M-S. Now you can quickly go back to the first if that is better. But with just about any non-professional musicians, the very first take is bound to be the best. Better have that "on tape" then.

Anyway, starting with ORTF in a decent setup is bound to be a good start. Don´t think too much, this is not a theory thing. Use your ears.

One very small tip given to me by an experienced engineer. Listen with only one ear, muting the other with a finger, and walk around the room to where it sounds best. Place your mics there.

Gunnar.

Cucco Wed, 03/30/2005 - 08:02

Gunnar,

There's some good information in your post, but I want to counter just a little of it.

First, the 3:1 rule was actually created for 2 microphones on the same source. Of course, this works fine for certain frequencies and on certain types of instruments, but it certainly holds little to no bearing on large ensemble stereo recording. (Or surround recording for that matter.)

I would also say, despite the level of experience of the recordist, there will need to be some tweaking of the mic positions. If someone claims that they are so experienced that they know the spot to place mics without experimentation, I would suspect their "knowledge" is more arrogance and less wisdom.

Also, I'm not too familiar with many groups that would take kindly to the shifting of the musicians. Perhaps, on the night of a blue-moon, I might be able to persuade the conductor to do this, but I certainly wouldn't push the issue. More often than not, I find that the conductors have actually applied some logic in how they arrange their musicians. I look at this as a challenge which I have to overcome - something I can prove my value with. If there were two recording companies in town - one that showed up, didn't request much of the musicians and the crew, but recorded everything and turned out a good recording versus the other who came in, requested changes in the group, spent an over-appropriate amount of time tweaking the set-up and also turned out a good recording - chances are, the group would hire recordist 1 again and let recordist 2 do their thing with other groups.

In other words, all things being equal (recording quality included), groups will stay with recording companies that give them good results without much work.

One last point and that's it - I swear. The idea about walking around and finding the best sound and placing mics is unfortunately a bit misguided. This works occassionally pretty well with certain types of piano, drum kit and a few others (including solo instruments) but for ensemble, I don't find that it works too well. The main reason is the height factor. If sound can change so dramatically based on 1 foot of movement in the horizontal plane, imagine the effects of 8 to 12 or more feet of movement in the vertical plane.

Sorry, I hate to sound like I'm poo-pooing, you're still cool in my book. 8-)

J.

anonymous Wed, 03/30/2005 - 09:47

Cucco. If I go with the Blumlein as the main mics should they go high in the air and do they need to be pointed downward? Is there a good starting point? Also as I have never used this technique before, Is there a chance of getting too much ambience from the back end of the mics.? Due to space I can probably only get about 15 feet back from the choir.And if I place the directionals in the back would ORTIF still be the way to go or XY? And I was just informed that one song is accompanied by Pipe organ which the pipes are behind the choir and the base of the pipes beginning at about 20 ft up. I have done two other recordings with this choir using spaced condensors and need to use a more distant technique as the Director likes more of the 'in the hall' sound as he puts it. Any last minute suggestions? I set up today so I hope to get a reply from you soon but if not thanks to all for the help . It is appreciated.

JoeH Wed, 03/30/2005 - 09:50

I take a zen approach to the ol' 3-1 thing as well. One must take in as much info as possible in the short amount of time you usually get to do a setup and soundcheck. Sometimes you have to fudge it to get the results you want.

And I agree, Jeremy; there's no way in the world that I'd have time to move people and mics around once we're past the downbeat at rehearsals, etc. I WILL NOT be the tail wagging the dog at rehearsals involving 90 voices, soloists and perhaps a 20-30 piece orchestra. They'd KILL me, then they'd call someone else in.

I try NOT to think about some of the $$ that's riding on a $10-30K rehearsal or concert; gives me the willies! Between paid soloists, orchestra fees, and hall rentals, it's a HUGE investment per concert, and my goal is ALWAYS to be as smooth and well-prepared as the pro's who are sitting there sight-reading everything like it's a walk in the park! :-) )

Following the "never let 'em see you sweat" rule, I take some time to think for a few extra minutes, walk around a little bit, and then finally put the mics where I hope they'll be most effiicent. (Admittedly based on past experience, too). I HATE to be huffing and puffing behind the condutor during dress rehearsals and such, making a racket, etc. (It's also very distracting to everyone onstage if you're doing this after the downbeat. They're trying to read music in front of them with one eye, and watch the conductor with the other; no way do they want to see mics moving around, people scurrying around, taping things down, etc.)

Fortuantely, I either know most venues now (rarely any left that I haven't recorded in, thankfully), or I've got enough time to set up ahead of time, or (and I tend to like this the best) it'll be a choir and they do a 20-30 minute warmup from 7 to 7:30. THAT's the time for final tweaks for us, if they're going to happen at all.

Sorry to hijack the thread....you guys just hit a good nerve on this topic of 3-1. 8-)

As you were, then!

FifthCircle Wed, 03/30/2005 - 10:20

Mike-

remember a basic concept when placing your microphones. The less directional the mic, the closer in they will likely have to be. Choral conductors like a certain sound of blend in their groups, but unless they really understand how microphones work, they won't be happy with a recording where you place the mics where your ears say they should be.

As I alluded to, think about the 3 different zones of reverberation. You have nearfield- where you are hearing all direct sound. Farfield where you hear no direct sound and midfield where you are getting a combination of the two. I find that the best classical recordings are done in a mid-field situation. You have the detail of a direct sound, but the ambience of a room. The distance for these sections will change depending on the decay time of the sound of the room.,

Our ears are incredibly sensitive about direct sounds. (it is part of our survival instinct.) Microphones pick up what they pick up. A directional mic can be placed further back than an omni mic. Remember the acoustic fields. I'll often place a stereo pair for soloists, etc... out front, but then have a pair of microphones in relatively close to the choir, but placed carefully to get the detail and blend. That usually means omnis close, blumlein/ortf/x-y out front. The omnis are usually placed high and angled down into the group... The two zones of micing gives me my sound. (Joe, this is almost exactly what I did on the Berlioz recording you heard at AES).

And I'll say it again... The 3-1 rule in area micing like this is BS. It is mild BS when you have 14 mics on a drumset, but complete BS in this situation. Heck, I've even had setups that follow the "rule" where there are phase issues (5 mics on a choir for example when recording and sound reinforcement is going on). Changing the kind of 2 of those mics (not even the position) from KM-84's to KM184's fixed the problem because the pickup pattern was sufficiently different. Use your ears and don't worry about arcane rules like that.

--Ben

anonymous Wed, 03/30/2005 - 11:11

Thanks Ben. After getting all the info I have from alot of generous folks from different forums I have decided to just go with a midfield pair. Would Blumlein ORTIF or XY be your choice or is it "try and see" As I said I have been informed that a pipe organ will be in one of the pieces. Pipes behind the choir. I have the luxury of being able to setup the day before and can experiment with voice but am a little concerned about height of the pair in respect to the pipe organ. I know there is no firm answer to this but do you think I should just try to capture voice and pipes with the one pair of mics and lower the height or leave them high or arrrrrrgh ............. any ideas?? at least ALL that responded agree on one thing. Forget about the 3 to 1 stuff.

anonymous Wed, 03/30/2005 - 12:12

Ben,

I'm about to do a recording of the Verdi Requiem --- regional pick-up professional orchestra and amateur chorus. I am limiting the set-up to 2 omnis (Earthworks QTC1) and two cards (Neumann KM184).

I was planning on putting my omnis out front as mains in A-B, and close-miking the choir with the KM184s, just mixing them in enough to get some clarity in the text. You would instead suggest ORTF out front with chorus pickups using omnis? (Remember, I have to capture that bass drum in the Dies Irae :)

Any other opinions?

Mike

FifthCircle wrote: Mike-

Our ears are incredibly sensitive about direct sounds. (it is part of our survival instinct.) Microphones pick up what they pick up. A directional mic can be placed further back than an omni mic. Remember the acoustic fields. I'll often place a stereo pair for soloists, etc... out front, but then have a pair of microphones in relatively close to the choir, but placed carefully to get the detail and blend. That usually means omnis close, blumlein/ortf/x-y out front. The omnis are usually placed high and angled down into the group... The two zones of micing gives me my sound. (Joe, this is almost exactly what I did on the Berlioz recording you heard at AES).

--Ben

FifthCircle Wed, 03/30/2005 - 12:19

hughesmr wrote: Ben,

I'm about to do a recording of the Verdi Requiem --- regional pick-up professional orchestra and amateur chorus. I am limiting the set-up to 2 omnis (Earthworks QTC1) and two cards (Neumann KM184).

I was planning on putting my omnis out front as mains in A-B, and close-miking the choir with the KM184s, just mixing them in enough to get some clarity in the text. You would instead suggest ORTF out front with chorus pickups using omnis? (Remember, I have to capture that bass drum in the Dies Irae :)

Any other opinions?

Mike

That is actually exactly what I would do... I've done a lot of chorus and orchestra recordings with a main pair in front of the orchestra (usually Blumlein in my case) so I have great imaging for the whole group and the omnis on the choir spaced to divide the choir in thirds.

In the Verdi, if you can spot the soloists, I'd do that too... The Verdi Requiem is really an opera that is performed on stage in the form of a Requiem Mass. Make sure they sound check the Diaes Irae as it is bloody loud.

--Ben

anonymous Wed, 03/30/2005 - 12:19

docvlak wrote: Thanks Ben. After getting all the info I have from alot of generous folks from different forums I have decided to just go with a midfield pair. Would Blumlein ORTIF or XY be your choice or is it "try and see" As I said I have been informed that a pipe organ will be in one of the pieces. Pipes behind the choir. I have the luxury of being able to setup the day before and can experiment with voice but am a little concerned about height of the pair in respect to the pipe organ. I know there is no firm answer to this but do you think I should just try to capture voice and pipes with the one pair of mics and lower the height or leave them high or arrrrrrgh ............. any ideas?? at least ALL that responded agree on one thing. Forget about the 3 to 1 stuff.

If the organ is behind the choir and you have no choice in repositioning the vocal forces, my first shot would be to use a stereo pair in ORTF and start by emphasizing the capture of the voices. There will be a tradeoff with balance with the organ, but the priority should be choral clarity. You will likely have more flexibility in capturing the organ well due to the size of the instrument, but there will be a compromise involved.

Mike

ghellquist Wed, 03/30/2005 - 15:01

Cucco wrote:
Sorry, I hate to sound like I'm poo-pooing, you're still cool in my book. 8-)

J.

Cucco, I feel I am learning all the time from you as well as the rest of the experíenced people on this forum. Hit me on the head when I believe I am right without beeing it (and my wife tells me I need quite a bit of that).

Gunnar

anonymous Wed, 03/30/2005 - 15:55

I just got back from setting up the choir project. I ended up putting the ORTIF with two cardioids about 10 feet in front of the choir and just for an option put the Blumlein about another 15 ft back from the ORTIF both about 2 to 4 feet above where the heads of the choir will be.(thats as far as I could go back with the Blumlein and nowhere in the back ,without being in the way, to put stands for room reverb without going to extremes to hang from a 40ft cathedral ceiling.) Just having my partner walk around the choir area talking and singing and yelling bad renditions of Beatles songs I found that I may well be able to use a mix of both pairs although I have to say the Blumlein sounded very nice by themselves with a good amount of room verb and still very present. I was very pleased to hear what seems to be a very smooth stereo image from left/ center / right in terms of amplitude and freq response from both pairs. Tomorrow will tell the tale. Well , going on and on but I wanted to give all you guys a very BIG THANKS of gratitude and if you were here the drinks would be on me. I'll drop a note when its over to let you know how it turns out. Once again. Many Thanks

Cucco Wed, 03/30/2005 - 18:02

Well, given that you've done the recording, I would think that it's a bit late to give advice since you've already done some of the work, but...

Since you are also doing pipe organ directly behind the choir - I would definitely try blum out front and then spot the choir with the cardioids. Unless your rather small choir is good at shouting in tune, they'll need some help. Sure, the organ won't sound as good as it possibly could, the Blum setup will yield decent results with it and then bring the spots in where help is needed.

J.

anonymous Thu, 03/31/2005 - 06:32

It would be easy to lower the front cardioids to bring them closer to the choir . I'll do that. This choir has been together for 12 years and are conducted by the Director of Choral Activities at the U of WIS so things are well under control as far as balance between the organ and the choir and we record the rehearsal and then the live show 2 days later so I do have a small window at the beginning of rehearsal to make small adjustments. But like you said earlier, The Conductor will be there to work and not watch us moving mics around. Thanks for this last minute tip. It wasnt too late. I record the rehearsal at 5 today. Again Thanks for your help!

anonymous Tue, 04/05/2005 - 07:36

Well the recording is done and it turned out nicely. My question now is .......The songs are extremely dynamic in levels. How would you approach getting gain on the overall and calming the peaks without squashing the performance? I have a good grasp on comp/limiting but mainly with rock/blues and was wondering if someone has specific suggestions for choir. Thanks

Cucco Tue, 04/05/2005 - 07:56

MMMmmm... Dynamic Range.

For peaks, it's perfectly acceptable to use a limiter. However, I'll qualify this quite a bit.

Only on extreme peaks should the limiter be hit. Otherwise, you will want most musical peaks to remain under the threshold of the limiter.

Personally, when I mixdown a live recording here are a few of the guidelines I use for dynamic range.

1. I like my room noise floor on the recording to average at around -65 - -70 dBfs.
2. I like my loudest selection to hit 0dBfs. Any "non-musical" peaks such as extreme cymbal crashes (not to say cymbals aren't music - simply, they can be excessively loud and if not tamed, can cause the recording to sound too soft. This goes for occassional BD hits, Tam-Tam, picollo, brake drum, etc.) may be limited or gain-riden down to a more moderate level.
3. I like my lowest sounding articulation to start as low as -50dBfs or lower. Of course, this seriously depends on the type of music. A disc full of Sousa marches just won't have this kind of dynamic range. The Mozart Requiem would have even more.

In general, I try to make it sound as dynamic as the concert/performance. You would think this would be easy - set the volume so you don't clip and you're cool, right? Nope, a little bit of gain riding here and there is essential. Most the time that conductors sit in as producer, I constantly hear "can you make that section quieter?" Musicians under the influence of concert adrenaline will have a tendancy to make things louder than usual. Including pp sections that really need to be super soft.

Very rarely do I ever use a compressor. Occassionally, I'll use it on wind ensemble/bands and just recently, I had to use one on orchestra. The pic was so forward and bright, I had to use a multi-band carefully tuned to tame her down.

Other than that, minimal dynamic processors are required.

I hope this helps.
J.

JoeH Tue, 04/05/2005 - 09:19

I always "Test out" any limiting I do to check if I can hear bad stuff creeping in before I commit. Usually, cymbals, plosives, even mouth-ticks (if it's a close-mic'd situation) often create useless peaks that should be tamed.

I'm just working on a jazz quartet piece that's just gorgeous; starts out small and quiet, and builds......and builds.......and builds, to something that's actually TOO big, so I have to tame the drummer a bit, separate the music track from the applause at the end, and GENTLY (with limiting) reduce the peaks that are making the dynamic range too wide and in general not usable for much in the "Real world".

If I can get those peaks tamed WITHOUT tampering with the overall sound, or messing up the rest of the transients, then it's a "go".

I usually use a very fast attack & release, and set the limiting for a brick-wall peak that I don't want to exceed. Then I process and listen, a/b to the original. Working in 24 bits or 32 float, this usually works quite well, and there's rarely any artifacts when done properly. In the worst scenarios, I'll use a multiband instead. Once I'm happy with it, I bring up the track to my nominal levels and move along to the next issue. 8-)