Audio Blown Out but not in the Red

[Jeremy Garchow]

How’d you capture it, meaning from what kind of tape and how was tit originally recorded?

[Katy Garton]

I shot it on a PD170 48 KHz and then captured DV-NTSC 48 KHz

[Edward Chick]

Did you record in mic or line level? If in mic, you overloaded the input. Not much you can do to fix it.

[Bouncing Account needs new email address]

I’d guess you over-drove the mic pre-amps in the camera.

If that’s the case, sorry, but its too late now to do anything that will effectively correct for that.

But remember this the NEXT time…

If you wish to USE the audio that you record… you must wear good headphones throughout the shoot to monitor the quality of the audio at all times.
If there’s an audio quality problem, try to fix it before you continue.
Audio meters alone are nearly useless.

It is just as important to the audio to monitor with headphones, as looking at the viewfinder is to the image quality.

[Adam Taylor]

or better still….hire a sound recordist for the day.

If you try do two or more jobs simultaneously (direct, camera, sound) , then everything will suffer, including your reputation!

The benefits you will get from having an experienced recordist will far outweigh the extra cost.

adam

Editor/Mixer
Character Options Ltd
Oldham, UK

[Bret Williams]

And make sure the audio guy monitors the camera output, and not their little mixer output! So often the audio recorded at the camera is overdriven because the camera record level is too high, but the audio being sent to the camera is fine. With all the confusion over digital and analog levels and headroom and tone this seems to occur more often than it should. At the least, make sure you (the camera op) monitors the camera audio or do some extensive testing to make sure the mixer and the camera record levels won’t produce any distortion.

[Thaxter Clavemarlton]

[Bret Williams] “And make sure the audio guy monitors the camera output, and not their little mixer output! So often the audio recorded at the camera is overdriven because the camera record level is too high,”

All well and good.

But we are fully back around to the SHOOTER wearing some monitor headsets, as well.

When I’m running the shoot from behind the lens… I am responsible.
I want to HEAR that its right.

[Tom Matthies]

Even though you were monitoring the sound and watching the meters, it’s easily possible to overdrive the recording on certain sounds. Many sounds which are short in nature or in the higher frequency ranges will over modulate a recording and cause distortion, espically with a digital format camera. These sounds can simply be too short in nature to give the meters a chance to react properly. Many camcorders will have the Vu meters damped a bit to show more of an average level, but they will not respond quickly enough to show the very short, but very “loud” peaks present in your material. Most professional field mixers will include both a “peak hold” option on the meters to indicate the loudest part of a sound and also a red (usually) peak indicator that has a very fast response time. I’ve actually recorded Native American dances locally here and I’ve seen my peak light on my mixer lighting up like a string of Christmas lights while the slower, averaging meter on the mixer showing levels in the normal range. Even though your waveforms look OK, clipping could have easily occured in the recording process. The waveforms in FCP while useful, are not terribly accurate and lack the detail that many professional sound processing programs can provide. Your recording was most likely over driven while recording and the waveforms lack sufficient details to show it clearly. In the future, use a good mixer (both electronic and human) and err on the side of bringing the audio down a little more. You can always bring it up and add a bit of compresser to it.
Once it’s clipped, there’s not a lot you can do to fix it.
Tom

[Jeremy Garchow]

[edward chick] “Did you record in mic or line level? If in mic, you overloaded the input. Not much you can do to fix it. “

That was my thoughts exactly.

Jeremy