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

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?

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

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.

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

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

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

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.

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

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".

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

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...

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.

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!

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.

Whew. Thanks for the input.

OK, I am getting details from the choir director in dribs and drabs. Also, I really, really get the point that I will have to work under far from optimum conditions. This is not a wrong venue and wrong production. It's right for the purpose, which isn't relevant to my concern here. All of those are details totally out of my control. I'm showing up to make something happen. I just need to salvage the best possible audio from this.

These are 6th grade kids, about 40 of them, from a school chorus. I've seen them perform before. They're focused and capable of acting and choreography, too. So far as I'm concerned, they're pretty polished, not the, um, bladder-challenged 3rd graders mentioned above.

I have a choice of choir risers or not. They're heavy and a pain in the ass, I am told, but I won't be moving them so I don't care. I'll gun probably for two rows of ~20 each on risers.

The microphone(s) will be in the shot. I can position my camera close (I'm using a wide angle lens adapter), so I think the director can keep the kids focused but be out of frame.

As I said above, I think the speakers will be a pretty lame school sound system: CD player, crude mixer/amp, and a pair of speakers on tripods. Criminy, I do NOT want to fuss around with phase cancellation, although I appreciate why this was suggested. I can keep only so many plates spinning at once. There will be no speakers sprinkled amongst the choir, either.

I'm beginning to like the lip synch option. Yet, here is the quandary: if potential bleed from speakers can occur in my outdoor venue, why wouldn't bleed also occur (perhaps more so) in an indoor venue where I record the kids singing under better managed acoustical conditions? These kids won't be wearing headphones, so they have to listen to amplified music, no matter where they sing. So how would I obtain a great singing track from an indoor venue (e.g., choir room) under these circumstances?

I really appreciate the thoughtful feedback. Do my comments above illuminate a better (yes, far from ideal, I know) solution? This is helping me to mentally prepare. I have a comfortable margin of time, i.e., a few weeks, before the event.

Finally, I saw last year's DVD of several school choirs doing this, some indoors, some outdoors. As I mentioned, some used on board camera audio (absolutely horrendous). Outdoors, some used a single large condensor microphone. Others used two or three small condensor microphones. No recordings sounded great, but they were serviceable for the purpose of the program. So, the bar is pretty low, but I would like to do the best possible job.

Cheers,
Steve

A fun gig, I like it! Did something very similar to this many years ago, but with a high school "glee" group. My plan used a few (4?) shotguns on stands spaced apart parallel to the front of the group about 10 feet out. We shot around these with a few BetaCams. The playback speakers were placed in between the mic stands and just behind the line to be on the back side of the mic elements. The playback level was not rock concert, but was loud enough for all of the kids to hear. Get the group to sing a bit louder than normal if you can, it will help with the outdoor ambient sounds you don't really want. I used a small Tascam mixer to sum the mics with a small amount of compression and minimal plate reverb, and also a direct feed from the playback machine. The mix plugged right into one of the cameras. Since the speakers were pretty close to the mics, the little bit of speaker the mics could hear blended right into the direct feed. We shot the whole song two or three times for video angles, the first take having a static wide shot beginning and end. In post, one take of my mix track serves for sound, they opened and closed with the static wide with title graphics, then just fit the rest from different angles from all of the takes to make it look like we had an 8 camera setup...since they are singing to the same track every take its pretty easy to mix and match visuals. The results were very good IMHO, both the video producer (local NBC station in Tampa, FL) AND the choir director thought it sounded great. Wish I could post a copy but I don't have any means of playing my copy on 3/4" video anymore... :-) Good luck!

Hey, Greg B., thanks very much for sharing a positive experience on how your gig worked. That is encouraging to me. If it worked in your BetaCam days, I don't see why I couldn't get almost the same thing to work now.

I have two small condensor cardiods (Rode NT-5 matched pair), which obviously have a different pickup pattern than shotguns. Since I have time to experiment, I think I'll set up my mics outside with a speaker system and see just how much bleed I actually get. Keeping in mind the K-I-S-S principle here, I really don't see a problem mixing and synching in post my soundtrack with a small amount of bleed recorded on location.

-Steve

If you have the ability to re-record the audio in a studio-type setting, you could try this technique for dealing with the backing track bleed:

1. Set up 3 stereo audio tracks in your DAW. Import the original backing track and place it on audio track 3.

2. Record the choir on audio track 1 using your mike technique of choice. Set the level of audio track 3 (the backing track) in the choir's monitor speakers so that it is just loud enough for them to hear and be able to follow along. Obviously, you want to mute audio track 1 in the choir's monitors so you don't get feedback.

3. Without changing anything, record audio track 2 with the choir remaining in place and as quiet as possible so that you're recording just the accompaniment playing back through the choir's monitor speakers. Again, be sure to mute audio track 2 in the choir's monitors.

4. Invert audio track 2. This will have the effect of canceling out the accompaniment, leaving only the voices.

5. Un-mute audio tracks 1 and 2, and balance the voices to the original backing track which is on audio track 3.

6. Apply any processing you think is required, and bounce to disk.

7. Sync this to your video

I've done this a number of times with high school choirs and had really good results.

Scott, that sounds like the best simple solution! Step 3 (recording the playback track only, with the choir standing quietly in place) is the key to making it work. Very well thought out.

Steven, two further advantages to lip-syncing using Scott's procedure:

1.) You can mic closer, without worrying about how the mics look in the shot. Micing closer will further reduce any bleed problems and will also reduce any recorded reverberation, which would sound out of place with the final outdoor camera shots.

2.) You won't have to worry about wind noise, trucks, airplanes, and other unwanted ambient outdoor sounds.

BTW, I'd roll off the extreme highs and lows on the playback system. The kids won't need those to stay in time with the music, and doing so will make the cancellation step work better.

That's a good suggestion, well worth a try.

Thanks, guys! I'm glad that I posted here and am able to think through this with more learned minds.

Scott, those steps make a lot of sense to me. It would take a lot of pressure off me while I record video of the actual event. Managing video and audio, I often feel like a one-armed wallpaper hanger. While I do not have a portable DAW, I can easily implement your procedure with the school's playback device and my field recording equipment. I'm pretty sure that I'll have a choir room at my disposal at the school.

Greg M.: thanks for the additional tips and advice. Again, those make a lot of sense.

I have not yet visited the outdoor venue to see how trafficked it is (human, animal, and vehicle). Assuming that I don't have to worry about egregious audio intrusions from trucks, sirens, etc., however, I'm wondering if it would make sense to mix into the studio recording just a little outdoor ambience so that the final mix has pristine singing that at least sounds like it was recorded on location. I'm thinking of so many kids' TV shows where, despite a kid singing outside, there isn't a hint of anything else; it screams "sanitary" to me. I guess in post I can see how this might sound.

-Steve

Hello Steven,

I've done this before, but not outside. PM me your email and I can send you a sample.

Placing the speakers behind the microphones is not necessarily a good idea. Remember, the speakers are directional too. ...so while putting them behind the microphones puts them closer to the null of the microphone, it puts the microphone in the direction of the speaker. Putting them in front puts the microphones in the null of the speaker.

You can also have the speakers behind the chorus at a reasonable volume. Whether this is appropriate depends on the material, the venue, and how loud the choir can / needs to sing.

Make sure you get a copy of the original track to overlay with your recording of the choir. You may need to process the original track with reverb or EQ to get it to match the space, through the bleed from the speakers may do this for you.

Ultimately, I'd worry less about the playback of the backing track and MORE about getting a great miking set-up on the choir. If you have a full, well-blended and well-spread choral mix, fitting in the backing track will be much easier, or at least more forgiving. I'm based outside DC and would be happy to help.

Cheers.

I can easily implement your procedure with the school's playback device and my field recording equipment. I'm pretty sure that I'll have a choir room at my disposal at the school.

I think the advantage of using a DAW is that the "choir" track and the "cancellation" track both have exactly the same timing. If you have any timing difference, the cancellation trick won't work perfectly. It's a given that playback devices and recording devices all have some amount of frequency instability in their timebases, resulting in some amount of drift from one take to the next. Hopefully if you record the cancellation track immediately after recording the choir track, the equipment will be reasonably stable and this won't cause too much difficulty. But be aware that it is, at least, a theoretical issue.

Record in the deadest room you can find, because too much reverberation will sound "hokey" with the outdoor visuals.

And yes, some outdoor ambience would be good, at least if there is an establishing long shot at the beginning and/or end of the piece, when nobody is singing. A few birds, crickets, a bit of traffic, a distant barking dog, whatever... all would sound much more realistic than perfect silence. By adding the ambience in post, you have some control over that 747 fly-by at 500 feet!

I think the advantage of using a DAW is that the "choir" track and the "cancellation" track both have exactly the same timing. If you have any timing difference, the cancellation trick won't work perfectly. It's a given that playback devices and recording devices all have some amount of frequency instability in their timebases, resulting in some amount of drift from one take to the next. Hopefully if you record the cancellation track immediately after recording the choir track, the equipment will be reasonably stable and this won't cause too much difficulty. But be aware that it is, at least, a theoretical issue.

Got it. This is one more detail I hadn't considered, but I do understand why you mention it. If I was an audio wonk, which I'm not, I'd have a DAW that I could tote around. I have a laptop (secondary computer) and I use Sony Vegas that can be used as a DAW, but I have no good means of audio in- and output on the laptop, certainly none that comes even remotely close in quality to my field recording gear. So, I think I'm stuck with the risk, however minor, that timing of the playback and recording gear might drift. In any case, I already planned to record the singing and 'cancellation' tracks back-to-back.

Record in the deadest room you can find, because too much reverberation will sound "hokey" with the outdoor visuals.

Yes, I understand. I was thinking of even a backstage environment with curtains drawn if no dead room is available. I even have a roll of Auralex StudioFoam that I could use.

-Steve

Hello Steven,

I've done this before, but not outside. PM me your email and I can send you a sample.

Thanks, Christian. Yes, I would if I could, but you have to update your profile with contact info to enable PM'ing. :)

-Steve

So, I think I'm stuck with the risk, however minor, that timing of the playback and recording gear might drift.

It might be helpful to record a few clicks on the track before the music starts, and also after the music ends. They be sure all those clicks are played back on the monitor speakers, and recorded on your mics. That way you can check the timing with sample-level accuracy, and perhaps stretch/shrink the "cancellation" track if necessary to match the "choir" track.

Yes, I understand. I was thinking of even a backstage environment with curtains drawn if no dead room is available.-Steve

That sounds like a very good place to record. The deader, the better, as it will still be more live than outdoors.

Of course only a few of the production design details have been revealed here. And Mr. Miller is absolutely correct that recording in a dead room will best simulate what a choir would sound like if actually performing outdoors.

However, I question whether that is necessarily what you should be aiming for. Even the very best choirs on the planet will be able to perform better in favorable acoustics (i.e. where they can hear themselves with some beneficial reverberation). And the more-so with amateurs (and/or children).

Pre-recording sound-only indoors eliminates the exterior ambient noises and mic placement problems of trying to record live outdoors. However no choir (and not much other types of music except maybe bagpipes) sounds better "dry" than "wet".

Disclaimer: I approach this as one who has been a choir singer (for 55 years) and a live, location audio recording engineer (for 50 years) and a choral conductor and a video producer for only a couple of decades. So my perspective is as much for the musical performance as for the act of recording audio and/or video of it.

It might be helpful to record a few clicks on the track before the music starts, and also after the music ends. They be sure all those clicks are played back on the monitor speakers, and recorded on your mics. That way you can check the timing with sample-level accuracy, and perhaps stretch/shrink the "cancellation" track if necessary to match the "choir" track.

Yes, I previously had the idea of adding a click at the beginning simply to sync, but adding one at the end, too, is a great idea for correcting any drift. Perfect. Thanks.

Of course only a few of the production design details have been revealed here. And Mr. Miller is absolutely correct that recording in a dead room will best simulate what a choir would sound like if actually performing outdoors.

However, I question whether that is necessarily what you should be aiming for. Even the very best choirs on the planet will be able to perform better in favorable acoustics (i.e. where they can hear themselves with some beneficial reverberation). And the more-so with amateurs (and/or children).

Pre-recording sound-only indoors eliminates the exterior ambient noises and mic placement problems of trying to record live outdoors. However no choir (and not much other types of music except maybe bagpipes) sounds better "dry" than "wet".

Disclaimer: I approach this as one who has been a choir singer (for 55 years) and a live, location audio recording engineer (for 50 years) and a choral conductor and a video producer for only a couple of decades. So my perspective is as much for the musical performance as for the act of recording audio and/or video of it.

OK, Richard, no need to feign modesty. :) If I had decades of recording experience, I'd likely be able to discern which of the plurality of ideas in this thread would be "best" for me and move on. Or not post at all. Still, I really appreciate your voicing concerns from experience. I understand, for instance, your remarks on dry vs. wet. This is why I mentioned above that I mix in ambient from the location to the studio mix.

These are rank amateur singers, not the Vienna Boys Choir, and I feel that the production details emerging here are beginning to appropriately coalesce with (1) my hobbyist experience and related limitations, (2) available production gear, and (3) the fact that implementing ANY of the ideas here will far exceed the production expectations of the school and organization for whom I am making this video. I can only do so much, then I draw a line. Factors (1) - (3) would not concern a pro, I know. I'm not that person.

What I have after just a few days of this thread's colorful life is a MUCH better idea of how to construct my production. Thanks, fellas. It's exactly what I need.

-Steve

Hey folks, after so much thoughtful help here, I just wanted to post back on my experience with the actual shoot. The bottom line: it was a smashing success.

I set up my microphones (matched pair cardioids) at the outdoors location just a few feet in front of the choir at ground level (~25 kids; two rows). Audio loudspeakers to play a backing track were positioned about 15 feet behind the microphones and aimed at the choir. It didn't take long to properly adjust mic levels and loudspeaker levels to assure that (1) I got pristine choir audio with (2) nearly no bleed of the backing track in my recording.

In post, I synchronized the vocal recording with the backing track and mixed. Danged if it didn't sound like a studio recording, but with just enough on-location ambiance to make it sound realistic. I don't have permission to post the final video here. Still, I wanted to acknowledge and express gratitude for the help I received on this forum.

-Steve

Great to hear! Hopefully the first of many projects.