Shooting Live Concert - audio question

[Bryan Litt]

I will be shooting a live concert during which somebody else will be mixing and burning a CD. What do I need to do to ensure that his CD recording matches up w/ my video? Basically, I'm trying to do double system sound with a video camera. Am I better off shooting DF or NDF?

Any input is appreciated. Thanks.

[Mike Rehmus]

As long as he records continuously and you record continuously, the separate sound should line up quite well.

DF & NDF have nothing to do with the video frame rate. Just how it is counted. There is no difference in wall-clock time with regard to the total number of frames recorded in any given time period.

[Bryan Litt]

Thanks Mike,

That's what I thought. But my other concern is that the CD records and plays at the same speed the video camera records and plays. Should I assume it will? I know very little about sound recording.... shamefully litttle.

[Ignacio Rodriguez]

In my experience the clock that drives sample rates in semi-pro gear is sometimes not very precise. So if you are using a semipro setup and/or the guy capturing audio is using something like a portable minidisk unit, you will most likely run into trouble.

The 'correct' way to do it would be using infrastructure driven by the same clock... this means renting expensive pro equipment and setting up cables to run house sync... having more people around to operate the stuff... quite a gig!

If your are both using high quality gear you might not run into trouble and perhaps might just have to do some minor corrections in the NLE.

Try to make sure he is using a solid hardware platform like Pro-Tools or a MOTU audio interface.

It might be better for you to use DVCAM for it's locked audio but only if you will in some way be using the audio captured in the camera and mixing it with the other guy's in some way.

[Bryan Litt]

Thanks Ignacio,

He is using ProTools and I will be using a Sony PD-150. It looks like we'll be in good shape.

I've often searched these boards for information, but never posted a question before. Thanks so much for your help. It is very much appreciated.

[Glenn Chan]

If sync drifts, you should be able to stretch the audio to fit. Don't pitch shift when doing it (pitch shift introduces gremlins into your audio).

2- If you can, use an auxiliary send (or another output from your mixer, if your friend has one) to your camera so it's a bit easier to sync stuff up in post. If you have to sync only once it shouldn't matter much.

[Alessandro Machi]

In theory, most newer recording devices should play back at the same speed as they were recorded at which actually keeps your task simpler.

Analog Audio cassette recorders will definitely drift on you, but most other recording devices should work fine.

Why have you chosen to play with fire and make the computer be the final and only word when it comes to sound recording?

If the computer system crashes for any reason what sound will you use? It seems more logical to make your video camera be the default sound recorder and then send an audio signal to the computer from the camera.

If you could tell us more about what you plan to do it might prove to either be a way for the forum to learn a new way to do something or we may save you from a lab experiment project that you didn't know was a lab experiment.

[Matthew de Jongh]

well my answer is going to be totally different from what everyone else said, but fwiw this is what i have done in the past with great results...

connect up to the sound board or whatever "line out" they can give you, preferably the "house mix" or whatever you can get that is a combination of all the sounds.

if the guy is mixing the sound live you want something like the "tape out" or "monitor"

i'm no soundboard expert but i have been lucky enough to record some stuff where they had some really knowledgeable sound guys.

so anyway, you want a place to get the best sound you can that is "line level" you don't want a speaker out.

then if you are lucky enough to have good wireless stuff you plug a wireless transmitter into the sound board out that i mentioned above and then it beams it to your camera.

other than having wireless, you can run a long xlr cable to the camera but it can really get you tangled up in wires. i've always done it the wireless way.

another option would be if you were fortunate enough to have a spare camera have that recording off of the soundboard.

but in my experience getting the sound off the soundboard, onto mini-dv tape directly in sync with the video is the easiest.

what i do is put the soundboard sound into one channel and then put the shotgun mic from on the camera into the other channel.

so i have the sound board on the left and the shotgun on the right

then in the mix you can put like 80% soundboard and 20% ambient/audience sound

the reason i do this is because i have found if you JUST put the sound from the soundboard (or from a cd recorded that day) it is weird, the video (i ASSume? shows people watching the concert?) but if the people are shown but the sound is crystal clear with no audience sound its very unnatural.

matthew

[Ignacio Rodriguez]

> connect up to the sound board or whatever "line out" they
> can give you, preferably the "house mix" or whatever you
> can get that is a combination of all the sounds.

This is actually a very good idea. Can save you a lot of time in post. Takes the sync problem out of the equation alltogether.

[Alessandro Machi]

House mix usually is not the best mix for a videographers purposes. There are a variety of reasons for this. However, that does not mean that the mix is unuseable.

Keep in mind that the house mix is for the house. The house mix sound can either end up being too bassy because they like it that way and think it sounds fuller to the audience, or if the house is full, a mass of people do absorb sound so the sound mixer may fiddle with the sound equalization to make it sound perfect for the audience, but not as good when that same mix is sent line level to you.

Also, WHERE the sound mixer is located can affect how they mix the sound, again another variable that may not jell with the line feed that they are giving out.

Do you realize how difficult it is for the sound mixer to get proper sound in a full auditorium through audio speakers and then have that identical sound go straight to the videographer via line level?
It's next to impossible because in theory you would want your line level sound to sound as "good" as a properly mixed live show, but the mixer is dealing with a 3D environment whereas the send you receive from the mixer is "dry".

However, a sound feed from the mixing console should be significantly better than just using your camera mike.

[Matthew de Jongh]

hey i said i wasn't a soundboard expert, i just know what terms different sound engineers have used in the past.

it seems that almost every time i had to explain for 2 minutes what i wanted...you just want whatever single feed they can give you that has all of the instruments, vocals etc. that is line level.

the other trick is to have lots of adapters. some of the little setups have only an rca out.

matthew

[Ignacio Rodriguez]

I would try to do this for using the feed:

(1) Get a small mixer with mic and line inputs (at least 4)
(2) Get a high quality stereo digital delay unit.
(3) Set up two condenser microphones next to the sound guy (he will usually work to make the mix sound as good as possible from his standpoint).
(4) Connect the line out to the delay unit and the delayued output to the small mixer.
(5) Connect the mics to the small mixer (will probably need Phantom power)
(6) Use the delay to compensate for the difference in timing in what the mics get from the speakers and what you are getting straight from the console.
(7) Use a pair of headphones to set up the right sounding blend of both signals.
(8) Connect the outputs of the small mixer to your camera.

If you want to work in mono, you can make it all much simpler by simply using a Microphone on one channel and the mixer on another and delaying the channel from the mixer's output in post.

[James Emory]

I totally agree with Matthew. I have done this many times for live concerts, plays, etc. I just took a single feed from the house or provided board into a Mackie board to control levels easier and output to a DV deck when mixing multiple cameras and straight into the camera via XLR when using just one camera. The audio has been perfect every time. You need to get there early to perform tests though to set your levels and get what you want. I would definitely record from the board if for no other reason, just for backup to the CD method.

[Alessandro Machi]

<<<-- Originally posted by Ignacio Rodriguez :
If you want to work in mono, you can make it all much simpler by simply using a Microphone on one channel and the mixer on another and delaying the channel from the mixer's output in post. -->>>

I've found that to be the safest, simplest, and best compromise for video shoots that are done on a shoestring.

All though I NEVER only use one camera. So I usually have four audio inputs to work with. Sometimes I'll do a mono from the board to both camera and use a sennhieiser on the camera for ambience.

Other times I'll do a stereo feed from the mixer on one camera and set up stereo ambience on the second camera.

The scary part with the stereo feed to one camera and the stereo ambience on the other camera is during tape changes. Suddenly you've lost your mix sound until both cameras are both recording again.