Exported wav files clipping in premiere?

[tuomassamout]

Hello everyone!

I've been working on the audio post of a documentary mainly intended for internet release. On the main bus I'm using the avid D3 limiter/compressor with the brickwall setting and -1.0 threshold. I've been really careful feeding the main bus and not letting anything actually hit the limiter.

I'v used two different meters on the main bus(avid Mastermeter and Mloudnessanalyzer) and both show the highest peaks at -2.0

All seems to work perfectly. The problem comes when the editor imports the final wav file to premiere and it's clipping.

I've checked the final wave with pro tools, audacity and cakewalk sonar and it's clipping in none of them.

The editor assures that there is no gain boosting going on in premiere. Could there be differences in headroom between PT and premiere?


I'm running out of ideas and would really appreciate the help.

cheers,

-Tuomas

[Carl Kolchak]

Does the editor have the stereo channels panned hard left, and hard right?

If they're both panned in the centre, they're summing together in mono, rather than being discrete channels - that would cause the level to apparently rise, and clip.

[Craig F]

Originally Posted by Carl Kolchak

Does the editor have the stereo channels panned hard left, and hard right?

If they're both panned in the centre, they're summing together in mono, rather than being discrete channels - that would cause the level to apparently rise, and clip.

If I had to put money on it this would be my bet

[The Weed]

While I agree with the above, it's been my experience that video editors require audio that does not exceed -20 dbfs (db full scale). I have an 002 Rack, which Avid has calibrated as 0 = -14 dbfs. Using Waves WLM meter on my Master to keep peaks at -21 dbfs works out to approximately a 7 db reduction in the signal coming out of Pro Tools. The editors at the TV station I do most of my work at now don't have to lower my files, they say the files are near perfect calibration for their FCP rigs.

Have your editor lower the files you sent by 7 to 10 db or use a metering plug-in to do the same at your end.

Cheers,

[Carl Kolchak]

Originally Posted by The Weed

Have your editor lower the files you sent by 7 to 10 db or use a metering plug-in to do the same at your end.

Cheers,

I really would not recommend doing anything along those lines.

O.P. said the file is clipping in Premiere - that's a different kettle of fish than not meeting broadcast specs.

If you start encouraging the editor to mess around with your levels, you're going to be constantly trying to hit a moving target, and QC will probably keep bouncing the program back to you - you'll fix it, the editor will tinker with it, and you're back to square one.

It goes without saying that the mix should be done in a properly calibrated environment, and when doing so, you barely have to look at the meters, as the mix would be painfully loud if it were 10dB over.

But make sure you have delivery specs, know where conversational dialogue aught to be, and what maximum peaks are allowed.

Read this thread, and look up info on the CALM act : couple of threads here, and another here.

[tuomassamout]

Hello,

Thanks everyone for the help, turned out the editor did have the tracks panned center. :)

Really appreciate the help and cheers for the links Carl, helped me figure out some monitoring issues in a temp room we are working in at the moment.

-Tuomas

[JFreak]

Also, if you mean "Focusrite D3" by saying "Avid D3", that is a compressor and not really a limiter. Anyway, that -20dB is widely used for transfers -- however, it is not peak value but a RMS value.