How Best to Record Choir and Soundtrack Outdoors

[Steven Reid]

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

[Greg Bellotte]

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!

[Steven Reid]

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

[Scott R. Shepherd]

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.

[Greg Miller]

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.

[Steve House]

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

[Steven Reid]

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

[Christian Brown]

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.

[Greg Miller]

Originally Posted by Steven Reid

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!

[Steven Reid]

Originally Posted by Greg Miller

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

[Steven Reid]

Originally Posted by Christian Brown

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

[Greg Miller]

Originally Posted by Steven Reid

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.

Originally Posted by Steven Reid

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.

[Richard Crowley]

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.

[Steven Reid]

Originally Posted by Greg Miller

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.

Originally Posted by Richard Crowley

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

[Steven Reid]

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