How Best to Record Choir and Soundtrack Outdoors

[Steven Reid]

I don't post often in this subforum, as my forte is video, not audio. Still, I'm not an expert at either, but I'm expert at asking for help. :) Please bear with me. I'm happy for slaps upside the head.

I will be filming a small choir at an outdoor venue. They will be accompanied by a pre-recorded soundtrack, i.e., not live music. I need to record pristine audio of the singing AND accompanying soundtrack. What I need here are a few technical pointers on how best to (1) set up my audio gear and (2) record what and when to mix it.

To the extent it matters, I feed audio sources (mics, etc.) into a Sound Devices 302 mixer (three XLR inputs, two outputs) and record on a Korg MR-1000. I have a small variety of microphones, one stereo and two mono. I'm not adverse to purchasing a few more for this project.

What I DON'T want is to record choir and amplified soundtrack (from speakers) simultaneously through the microphones, on the presumption that I won't get quality soundtrack this way. So, how do I best handle the soundtrack? A few ideas I have are:

1. Place small speakers far behind the microphones so that the choir can hear the soundtrack but microphones won't. Then, synch soundtrack and singing in post.

2. Feed singing and soundtrack into my SD302 in the field, mix levels appropriately, and record both simultaneously. Then, could I realistically avoid "contamination" of soundtracks, i.e., one amplified through speakers (and possibly picked up by microphones) and the fed into the mixer?

3. Something else/better?

Finally, I'm of a mind to record the choir with a matched pair of mono microphones instead of a single stereo mic. Sound reasonable?

Sorry for the verbosity. I was trying to aim for clarity rather than brevity.

Thanks for assistance.

Steve

[Steve House]

Is this an actual performance being shot before a live audience or is it a "music video" shoot where the sole purpose is to shoot the video, no audience present?

[Steven Reid]

Originally Posted by Steve House

Is this an actual performance being shot before a live audience or is it a "music video" shoot where the sole purpose is to shoot the video?

Hi Steve, there will not be a live (or any) audience. The sole purpose is shoot the video with best possible audio, a "music video," as you say. It's just the choir, directors, and me.

-Steve

[Steve House]

Is the instrumental portion already recorded or will you be recording it then adding the choir?

Where I'm going with these questions is either to record the choir in-studio at the time as the instruments or if that accompanyment is already recorded, with it playing for them through headphones, then shoot the choir lipsyncing to playback for the video. No audio other than ambience actually recorded at the location.

[Steven Reid]

Originally Posted by Steve House

Is the instrumental portion already recorded or will you be recording it then adding the choir?

The instrumental portion is already recorded (sorry, maybe my first post wasn't clear on this point). I have it in hand now, as a matter of fact. Hence, on performance day the choir will be accompanied by this very same instrumental portion, presumably through a small 'boom box' or other lame portable stereo system. At the risk of being pedantic, I would add that the choir NEEDS to hear the soundtrack as they sing (they're kids, so they REALLY need to hear it).

Steve

[Steve House]

See my editied post above, though I didn't reallze they were kids. That might make lip sync diffcult - so much for that idea

[Steven Reid]

Originally Posted by Steve House

See my editied post above, though I didn't reallze they were kids. That might make lip sync diffcult - so much for that idea

Gotcha. I understand your thinking, Steve. OK, there is no studio and definitely the kids will not be wearing headphones. (Dunce that I am, I had thought of your solutions before I posted, but I'm stymied by the constraints I tried to describe above.) Everything must happen on location at the outdoor venue. It's a one shot chance.

Is my idea #2 above a workable one? My concern is that the ambient sound would contain not only the singing, but also the amplified soundtrack, albeit on different 'sides' of the microphones. Yet, if the microphones are directional enough, and the kids' singing hot enough, then I may not pick up the ambient soundtrack.

Sheesh. I hope I'm not overthinking this. I have one shot and I don't want to mess it up.

Steve

[Steve House]

If you feed the playback device to your mixer on location and also record the choir, mixing it on site, (your option 2) the bleed from the speakers into the recording mics will be slightly delayed compared to the feed arriving direct at your mixer from the playback device and that could present problems. Your option 1 seems the best to me, since you can slip the playback track slightly forward or back during post to remove the 'echo' effect of the time delay.

[Steven Reid]

Originally Posted by Steve House

If you feed the playback device to your mixer on location and also record the choir, mixing it on site, (your option 2) the bleed from the speakers into the recording mics will be slightly delayed compared to the feed arriving direct at your mixer from the playback device and that could present problems. Your option 1 seems the best to me, since you can slip the playback track slightly forward or back during post to remove the 'echo' effect of the time delay.

Yes, that makes sense. In fact, you gave me an idea: I can edit the soundtrack to include a sharp pop a few seconds before the music begins. That will give me a nice audio and visual waveform marker in post to match the (low level) ambient instrumental and recorded instrumental to accommodate any slight delay, as you say, and also synch with the camera sound (I use PluralEyes, so this should be easy). I think that should do it.

Thanks for helping me think through this one...practically in real time! Much appreciated.

Steve

[Richard Crowley]

I have been recording choirs of all sizes for many decades. I would not even attempt to do this.

1) Reducing the acoustic pickup of the tracks might actually be easier outdoors, but...
2) Properly micing a choir is tricky indoors and doing a decent job OUTDOORS is very very very difficult.
3) But most importantly: NO choir can sing at their potential (at whatever level they are) outdoors. I am surprised that the conductor even wants to attempt this.

I would record the choir in a proper (indoor) venue and just "lip sync" the outdoor shot to the recording.
EVERYONE (You, the conductor, the singers, the editor, the viewers) will be happier. Guaranteed.

I believe that the proposal that as kids, they won't be able to lip sync, is not supported by experience. Most kids are smarter than you think, and they all know what lip syncing is unless they've been living in a commune off the grid somewhere. Furthermore they are lip-syncing to THEMSELVES, and the closer you can schedule the audio recording and the video shoot (same day?) the better their "muscle memory".

[Steven Reid]

Well, Richard, I appreciate your frank advice. In my case, the venue is etched in stone. I have no choice but to work with ouitdoor conditions.

Whilst my initial reaction to lip synching was to discount it, I am now more inclined to suggest this to the director. Same kids, same song, same soundtrack. Yes, I can see that working.

I just viewed last year's production, not shot or edited by me, and the quality was all over the place. Uncle Bob with a handycam and on-board audio to tripod mounted cam and multiple microphones. I have a hunch that I might surpass all of these in quality, even though the bar I have to clear is FAR from pro.

Again, thanks for weighing in with your experienced viewpoint.

Steve

[Greg Miller]

It certainly sounds like a challenging problem to solve. Recording a choir outdoors would be tough enough.

If the playback is loud enough to be heard at the location where the kids are standing, then it will be loud enough to be "heard" by your mics. Of course a more directional mic pattern will reduce the bleed somewhat, but it will also make it harder to mic the entire choir (unless it's a really small group). I guess you could put a lav on each kid and use a zillion-channel mixer.

If you make the music playback soft (to minimize bleed) then the kids will sing quietly... if they sing loudly they won't be able to hear the playback.

How many singers in the choir? Can your mics be in the shot?

How professional are the singers? "Kids" could possibly mean the Columbus Boys Choir, or it could be a bunch of local school kids with no real training. If the singers are well-trained, they would need very little playback, to keep them on pitch, *if* there's a conductor to keep them in time with the instrumental track. If the conductor is out of the shot, he/she could listen to playback on headphones.

Lip sync sounds awfully appealing...

[Steve House]

Good point, Greg. When the OP said "kids" I immediately thought of a group of about Grade 3 students, the typical elementary school or junior Sunday school class where some are singing, others just looking around, and some holding themselves cause they've gotta go potty and teacher is going nuts just trying to keep them from wandering off-stage in the middle of the song. Lip sync for them would be impossible. But if it was a well rehearsed choir of middle school or high-school aged music students, it could work.

[Paul R Johnson]

I also agree that you're on a hiding to nothing on this one. Wrong venue, wrong production design -

Having done (not always successfully) these kinds of things, two tricks have proved worthy of trying. Wind will wreck these, but in still air, it can work reasonably.

Scrub the idea to record in stereo, and use a central omni directional microphone just forward of the conductor position for a large choir, overhead at a height to get it away from the camera line - suspended on thin cable from the sides. Then fire the playback track in from both sides but with the polarity to one of them reversed. In still air, with careful placement, they tend to cancel out to a degree, and you hear mostly choir, and nowhere near as much track. As an alternative, a flown x/y pair of condensers will give a nice realistic stereo field, but the track is a problem. It looks bad, but a pair of speakers on stands at head height central facing the same direct as the flown pair won't be picked up too badly by the overhead cardioids, as they're facing the same way and you won't get reflections outside. The trouble is that all these look pretty ugly and certainly visible. You may get away with the mics, but speakers are always ugly!

Spaced cardioids A/B style can work fine, but getting the track out of them will be tricky.

The big problem with a large choir will be that they won't be able to hear the tracks, unless they are loud. The only saving grace you have is that outside small speakers, with not much bass are fairly directional, and not much will bounce back to the mics. Inside it's a major problem, less of one outside.

Are the choir on the flat or tiered? If they're on the flat, you need height for the mics to be able to pick out the rear rows. Tiers are simpler. The only other trick I saw that seemed to work were lots of small loudspeakers on mic stands distributed within the choir - much less visually obstrusive - and they can face away from the front and can be run at a lower level, which lets people hear them, but not let them be seen so much.

Proper planning is critical - you've been dealt a poor hand, but results can be ok. The trouble is really audio. Choirs sound totally and utterly flat and thin outside. If you sweeten it with reverb, it sounds artificial. Whatever you do, they sound rather like a football audience. I recorded a few gospel big shows at football grounds, and thousands of pretty good singers still sound like they're in a football ground!

[Greg Miller]

Originally Posted by Paul R Johnson

The only other trick I saw that seemed to work were lots of small loudspeakers on mic stands distributed within the choir

Taken to its logical conclusion... earbuds.

Still a lot of answers needed from the OP before we can come up with any better ideas.