Is this clipped? at DVinfo.net

Dennis Stevens · March 30th, 2008, 02:42 PM

This is from a documentary I'm working on, and playing the sound back on this interview, it sounded clipped and distorted.

I had one channel from a wireless to the sound guy's laptop, then to my camera. The other channel was a shotgun mic directly to the camera. When filming I don't recall seeing clipping on either channel.

I'm throwing myself on the mercy of the board here, would someone listen to this sample, and can you tell me if it is indeed clipped, and nothing can be done about the distortion? Or is it something, and perhaps it can be cleaned a little bit.

http://www.mediafire.com/?jddg4m0ymsl

We did a bunch of interviews in a row with no problem, and this one, the most important one, of course we have a problem.

Jim Boda · March 30th, 2008, 04:06 PM

Quote:

Originally Posted by Dennis Stevens

This is from a documentary I'm working on, and playing the sound back on this interview, it sounded clipped and distorted.
....

It looks clipped ...partially. But, the low recording level is not consistant w/ a clipped recording. It's odd that both channels are clipped at a low recording level coming from two separate sources.

What camera did you record to? What mics did you use? Was the soundguy's version of the recording on the laptop also distorted?

Did you try re-capturing the tape?

Steve Oakley · March 30th, 2008, 04:07 PM

yes its clipped. most likely the result of a signal level mismatch somewhere which was probably the laptop inputs if using the 1/8" in, or if using some sort of audio interface, line level into mic level :(

not a lot you can do... ADR ? there is supposed to be a very expensive declipping plugin for protools which I have not been able to test out. I've messed with some other declipping plugs with mixed results. basically you would have to normalize, then gain up 0 or +.5db to force everything to clip a bit, then run the plug. they don't seem to do much if the audio is clipped, but not at or close to 0db.

Steve House · March 30th, 2008, 04:26 PM

Opened it in SoundForge - pretty ugly stuff. Sure looks like severe overload of the recording inputs. Even though the levels are low, if the clipping occurs before the recording amps their level controls will have no effect - all they'll do is make the clipped signal louder or softer. This is the sort of thing that can happen if, for example, you feed a line level signal into a mic level input. I think you'll need to apply the reshoot plugin or go to ADR.

Richard Gooderick · March 30th, 2008, 05:27 PM

You must be gutted. That's such a good interview. He tells it so well. What a shame.

i just don't understand how this can happen on both mics.

Petri Kaipiainen · March 31st, 2008, 12:03 AM

Quote:

Originally Posted by Dennis Stevens

When filming I don't recall seeing clipping on either channel.

"Hearing clipping on either channel" you must certainly mean. Or were you not using headphones?

Clipping on laptop side can be either from transmitter clipping or laptop input clipping (line into a so-so mic input maybe). On-cam shotgun clipping seems unlikely, did you have the laptop signal accidentally feeding both channels?

Just speculation, not able to listen to the file while travelling.

Richard Gooderick · March 31st, 2008, 04:06 AM

I just had another thought. I filmed an interview on my Cannon A1 using a shotgun and lavalier. At least I thought I did.
When I put it into the NLE I realised I had been recording via my onboard stereo mic. The switch is in a submenu on the A1 and the LCD display warns you when the XLR is on. Not when it's off.
This wouldn't explain the clipping but it would explain why it appears that both channels are clipped using two different sound sources.
Could this have happened here?

Dennis Stevens · March 31st, 2008, 08:49 AM

Thanks for everyone's input. Well, I thought one channel was a shotgun mic going directly to the camera, but I can only surmise that didn't actually happen. Someone set up the microphones and said 'the mics are set up the way you asked'. Guess it always pays to check yourself.

We had a new sound guy working with us this time, so I don't know all the details of how he was set up. I wasn't wearing headphones, but the sound guy and the camera operator were. They never said anything about clipping.

I was basically hovering over the laptop that was recording to DVRack. Didn't see any clipping or dangerously high levels.

In the past, when I didn't have a sound guy, I just attached microphones to xlr cables, xlr cables to my camera (JVC GY HD 100) and watched the levels. Pretty clean sound doing it the simple way.

March 30th, 2008, 02:42 PM	#1
Dennis Stevens Major Player Join Date: May 2006 Location: Boston, Massachusetts Posts: 425	Is this clipped? This is from a documentary I'm working on, and playing the sound back on this interview, it sounded clipped and distorted. I had one channel from a wireless to the sound guy's laptop, then to my camera. The other channel was a shotgun mic directly to the camera. When filming I don't recall seeing clipping on either channel. I'm throwing myself on the mercy of the board here, would someone listen to this sample, and can you tell me if it is indeed clipped, and nothing can be done about the distortion? Or is it something, and perhaps it can be cleaned a little bit. http://www.mediafire.com/?jddg4m0ymsl We did a bunch of interviews in a row with no problem, and this one, the most important one, of course we have a problem.

March 30th, 2008, 04:26 PM	#4
Steve House Inner Circle Join Date: Mar 2005 Location: Hamilton, Ontario, Canada Posts: 5,742	Opened it in SoundForge - pretty ugly stuff. Sure looks like severe overload of the recording inputs. Even though the levels are low, if the clipping occurs before the recording amps their level controls will have no effect - all they'll do is make the clipped signal louder or softer. This is the sort of thing that can happen if, for example, you feed a line level signal into a mic level input. I think you'll need to apply the reshoot plugin or go to ADR. __________________ Good news, Cousins! This week's chocolate ration is 15 grams!

March 30th, 2008, 04:07 PM	#3
Steve Oakley Trustee Join Date: Apr 2006 Location: United States Posts: 1,158	yes its clipped. most likely the result of a signal level mismatch somewhere which was probably the laptop inputs if using the 1/8" in, or if using some sort of audio interface, line level into mic level :( not a lot you can do... ADR ? there is supposed to be a very expensive declipping plugin for protools which I have not been able to test out. I've messed with some other declipping plugs with mixed results. basically you would have to normalize, then gain up 0 or +.5db to force everything to clip a bit, then run the plug. they don't seem to do much if the audio is clipped, but not at or close to 0db.

March 30th, 2008, 05:27 PM	#5
Richard Gooderick Major Player Join Date: Oct 2007 Location: London, UK Posts: 795	You must be gutted. That's such a good interview. He tells it so well. What a shame. i just don't understand how this can happen on both mics.

March 31st, 2008, 04:06 AM	#7
Richard Gooderick Major Player Join Date: Oct 2007 Location: London, UK Posts: 795	I just had another thought. I filmed an interview on my Cannon A1 using a shotgun and lavalier. At least I thought I did. When I put it into the NLE I realised I had been recording via my onboard stereo mic. The switch is in a submenu on the A1 and the LCD display warns you when the XLR is on. Not when it's off. This wouldn't explain the clipping but it would explain why it appears that both channels are clipped using two different sound sources. Could this have happened here?

March 31st, 2008, 08:49 AM	#8
Dennis Stevens Major Player Join Date: May 2006 Location: Boston, Massachusetts Posts: 425	Thanks for everyone's input. Well, I thought one channel was a shotgun mic going directly to the camera, but I can only surmise that didn't actually happen. Someone set up the microphones and said 'the mics are set up the way you asked'. Guess it always pays to check yourself. We had a new sound guy working with us this time, so I don't know all the details of how he was set up. I wasn't wearing headphones, but the sound guy and the camera operator were. They never said anything about clipping. I was basically hovering over the laptop that was recording to DVRack. Didn't see any clipping or dangerously high levels. In the past, when I didn't have a sound guy, I just attached microphones to xlr cables, xlr cables to my camera (JVC GY HD 100) and watched the levels. Pretty clean sound doing it the simple way.