Recording choir with backing track playing out loud?!

[Mark6432]

I have experience in recording, so understand the concepts of tracking with headphones etc. but I'm recording a theatre group choir on location in a few weeks and have a query. I seem to recall reading somewhere that it is in fact possible to record with a track played out loud (it might have even been on SOS's very own Peter Gabriel article last month). Anyway, is there a way of recording a choir along with a backing track monitoring live? Or am I being overtly optimistic?!

Naturally I always strive for the best recorded/produced sound I can (using decent equipment) but given that I'm recording an amateur theatre group, in a less than ideal location, I'm not looking for top end hi fidelity on this project.

Any advice most welcome!

[Guy Johnson]

It is possible, and can work very well. Choir needs to be rehearsed, needs a good conductor, a good room, mic placement and a few decent monitors.

[The Elf]

1. Flip the polarity of one of a pair of speakers used for mono backing playback. As far as possible, try to place the playback speakers equidistant from your recording mic(s).

2. Before or after recording the choir, take a recording of the playback spill alone. Flip the polarity of this track and play it back with the choir recording.

With a combination of the two methods above you should be able to remove most of the playback spill.

[Mark6432]

Thanks guys, that's really useful……much appreciated. I'm not a massive techie so just to double check…

1) I use one of a pair of monitors, playing the backing track (set to mono on DAW) equidistant from mics.

2) Having recorded just the spill from the single monitor (no choir), I play this back with flipped polarity in Logic.

3) Once all recorded I have channels 1/2) Choir 3) Backing track mono (switched polarity) 4) Actual backing track in stereo.

A few questions:

I only have a small pair of Genelecs but can probably get hold of a Roland amp. Will doing a line out from interface into this, with polarity switched on DAW will do the job?

When you say equidistant do you mean between speakers and mice and choir and mice? Is there an advised layout to achieve this desirably?

Thanks again.

[Russell B]

Last year I recorded live a combined choir from Dumphries Scotland and Gifhorn in Germany (60 teenagers)and needed to isolate the piano which was played live for the 2 performances.

To enable the choir members to hear the piano I placed a monitor each side of the stage behind and below the back row of the choir (they were standing on a platform). As the piano was also recorded as a midi track I was able to keep the spill to a minimum. Maybe you could do the same it worked wonderfully and they have since released a CD from the concerts.

Russell

[The Elf]

You seem to be getting confused and over-complicating things!

Place a pair of speakers roughly equidistant from the mic(s) through which you are recording the choir.

Play the backing track in MONO through BOTH of these speakers, but wire one of the speakers with the polarity flipped. What this means is that a great deal of the spill is cancelled at the microphones.

Record one pass of the mic(s) without the choir singing, but with the backing track playing. Make sure you keep everything IDENTICAL to when recording the choir. What this does is record the remaining spill ONLY. Now when you flip the polarity of this recording and play it back simultaneously with the choir recording it will further cancel further the remaining spill.

Hope that clears things up for you!

[Hugh Robjohns]

Can I add to that by saying, keep the choir in place when recording the backing track pass because their presence will affect the acoustics significantly. Also, you can help the rejection by placing the monitors in the nulls of the Mic polar patterns, or behind the choir so that their bodies soak up much of the sound. Alternatively, the closer the monitors are to the choir, the less level you'll need... And if you roll off the monitor low end you'll also get less spill as the monitors will be more beamy

HTH

[mjfe2]

Place a pair of speakers roughly equidistant from the mic(s) through which you are recording the choir.

Play the backing track in MONO through BOTH of these speakers, but wire one of the speakers with the polarity flipped. What this means is that a great deal of the spill is cancelled at the microphones.

Record one pass of the mic(s) without the choir singing, but with the backing track playing. Make sure you keep everything IDENTICAL to when recording the choir. What this does is record the remaining spill ONLY. Now when you flip the polarity of this recording and play it back simultaneously with the choir recording it will further cancel further the remaining spill.

I would love to hear the results of this, before and after polarity inversion! To the OP, please post some audio examples once you're done!

[Urthlupe]

I have experience in recording, so understand the concepts of tracking with headphones etc.

Off topic - Mark, really liked the Aquarelle album - I'm just beginning something similar and in fact bought it for reference - great work!

Loopy

[The Red Bladder]

I've just recorded a 20-piece choir and gave them each their own SM57 or 58 to hand-hold and yodel into, with the solo voices on Neumanns.

It was thus that the conductor/choir-master discovered for the first time that two of the members were just not singing! They were just lip-syncing/mouthing the words! The tracks were completely blank, except for background noise and hand noise.

"You are only coming through in waves.
Your lips move but I can't hear what you're saying."

I believe words will be spoken!

[ConcertinaChap]

I'm sorry, I just had to share that story on Facebook, it's just too good

CC

[Exalted Wombat]

You seem to be getting confused and over-complicating things!

Place a pair of speakers roughly equidistant from the mic(s) through which you are recording the choir.

Play the backing track in MONO through BOTH of these speakers, but wire one of the speakers with the polarity flipped. What this means is that a great deal of the spill is cancelled at the microphones.

I've never quite understood why this stops the microphones "hearing" it, but not the singers.

[Hugh Robjohns]

The assumption is that, since the speakers are operating in opposite polarities, and equidistant from the mics, the monitor sound will self-cancel to a helpful degree at the mic's position. The singers, not being equidistant from both monitors, will receive some usable signal.

Of course, this technique only works if the recording mics are placed in the same point -- ie, a coincident pair -- and have the same sensitivity to each monitor...

Placing the monitors in the mics' null axes is a more reliable approach, but the technique of recording a second pass with the monitors running, but the choir muted (and then aligning this second pass with the monitors+choir recording, but in opposite polarity) works considerably better.

H

[The Red Bladder]

I'm sorry, I just had to share that story on Facebook, it's just too good

You're welcome!

It all started because of the subject of this thread - playing without headphones. The gig is the vocals to a musical. We have already recorded all the instruments over the past few months and mixed down to a single stereo working mix.

The choir MD wanted a no-headphone session, but was also worried about some choir members being "a bit weak and could you do something to bring them up a bit?"

No problem, just do the SM58 thing and have a single speaker with the bass reduced and behind the conductor. The four soloists were separated off, so we had just 16 mass yodellers in the room, each with a 58 or 57 and as requested, no headphones. This had the advantage that we could retune the individual singers and 'Vocalalign' them in editing (export from Radar to Reaper, before you ask!) It's a big project costing thousands, so everything has to be just so!

I noticed that two were reluctant to take the mic in their hands and said that they were not used to singing like that. I told them to put leave the mics on their stands, but get up close - which, on the first run through, they both didn't do!

Every time I moved the mics closer to where they were standing, they backed away. In the end, the choir master insisted that they take the mics in their hands.

"Pretend it's a hairbrush!" I suggested.

The referee blew the whistle for kick-off and I hit the big red button labelled REC and off we went.

Eighteen tracks of wiggly black on red WAV forms were written to disk, but those two remained plain red (no wiggly black) and empty of sound. The choir master came into flight control to have a listen to the tracks after the session and noticed that two tracks didn't seem to have recorded anything.

"Two tracks didn't record!"

I obviously couldn't have them believe that there might be a technical problem (refund, never heard of the word!) so I solo'ed them and cranked up the gain and all we got was bleed from the other singers, the playback and some handling noise. I had already noticed the fact that these two were not singing, but thought it was best to keep my beak shut. But now the game was up!

"Blimey!" said the choir master. "I thought those two were a bit weak, but that is, well, um, er. . . I think we are going to have to re-audition some of our members!"

They are back in soon, so we shall see and hear what transpires!

If I had gone for a more conventional setup with overheads and a stereo pair, their secret would have still been safe!

[Exalted Wombat]

No problem, just do the SM58 thing and have a single speaker with the bass reduced and behind the conductor. The four soloists were separated off, so we had just 16 mass yodellers in the room, each with a 58 or 57 and as requested, no headphones. This had the advantage that we could retune the individual singers and 'Vocalalign' them in editing (export from Radar to Reaper, before you ask!) It's a big project costing thousands, so everything has to be just so!

Isn't the FIRST step in getting things "just so" choosing performers who won't need "correction"?

I suspect the silent chorus members weren't dumb, just mic-shy. Individual mics must have been quite intimidating for a lot of them. And were they all holding the 58s at the same distance, getting the same amount of proximity boost? I see a danger of getting a recording of 20 soloists (well, 18 rather than 4 soloists plus a chorus.

[The Red Bladder]

The engineer is not the producer.

The studio owner ain't the producer either.

Engineers who think they are producers are about as welcome in a session, as a dog with diarrhoea on a long distance car journey! My job is to press that big red button labelled REC and shut the f**k up!

[Exalted Wombat]

The engineer is not the producer.

The studio owner ain't the producer either.

Engineers who think they are producers are about as welcome in a session, as a dog with diarrhoea on a long distance car journey! My job is to press that big red button labelled REC and shut the f**k up!

Oh right. I thought YOU dreamed up the idea of 16 individual mics!

[Jeraldo]

Why not just provide the reference track(s) to the conductor on headphones? Or is there no conductor/director?

[Mark6432]

(My last reply doesn't seem to have posted so apologies in advance if this is repeated)

Thanks for all advice thus far, Elf especially.

A few concerns as I'm doing the recording tomorrow:

I've only got a pair of genelecs and a Roland amp. I'm not sure how to achieve reverse polarity without soldering (which I'm not very confident doing), I'm guessing it's not possible on my Presonus Firestudio project. Can you use the gain plugin to reverse polarity on one output in Logic.

Or, can I do the whole thing using Roland amp?

I'd really appreciate any advice at this late hour!

[Guy Johnson]

Don't worry about reverse polarity. As long as the choir can hear the timing and the key, it will be fine.

[saltybrian]

Wow.

I logged on to ask advice for a group of 5-9 year old singers I'm recording today to find this right at the top of the page.

Thanks very much