I've noticed this before and never found a remedy but when I import an audio file (aiff or wav), it comes in very very hot. The levels are pinned and the track therefore ends up distorted sounding. I've tried all the import setting variables and nothing seems to help. By the way the source files sound fine, it's only on import into the Avid that they get blown out. Any thoughts?

 To what are the bit rate and sample rate set for import? Your files should come in filling the entire digital spectrum but they should not distort. If you lower the level, is the distortion still there or does theh sound file play back without distortion?

adam5000:

Any thoughts?

If you digitally import then the resultant file will have an identical level to the original. Many CD's are mastered to -.0000000001db for maximum loudness without digital distortion and many audio people mix to that sort of level causing your apparent problem

Most video production works on levels down from -12db down to a defacto standard of -20db. This means you will need to reduce the level of most audio imports from non video sources.

You may want to first calibrate your audio coming out from the avid into your monitors, to make sure you aren't overmodulating any of your signal. You can play a calibration tone from the audio tool and adjust the settings on the mixer, to make sure they arent out of whack, (should hit the 0dB on a mackie, for instance.) Then check your audio project settings, input tab. I believe you are using Mojo, not sure if is Mojo SDI, but there is an input gain menu adjustment you can make there. Just make sure someone hasn't accidentally changed your settings to +6dB.

Also make sure that you are not in some way summing the levels of the two elements in a stereo track. That might be a cause for overmodulation.

As Andrew wrote, files will be imported as hot as they are, sample by sample, bit by bit. The bit depth does not influence the peak levels, only the bottom of the spectrum.

Generally, music tracks, especially from CD's, use all of the available headroom, and do in no way compare to broadcast levels. Lower the levels 10 or 12dB's and see what happens.

Indeed, I second the suggestion to calibrate your audio monitoring chain.

you might check if you're sending both left and right to center- I think you want to make sure audio is set to "L/R alternating"

 

Some audio software treats -14 dB as 0 VU, while Avid defaults to -20 dB.  If that's what you're dealing with your audio on import will be 6 dB too hot.

jwrl:

Some audio software treats -14 dB as 0 VU, while Avid defaults to -20 dB. 

That would be hardware, not software calibration. It would mean a difference in the analogue outputs, not on the digital scale.

You're quite right Job, I should have worded that "Some audio software treats roughly 40% of peak as reference level, while Avid defaults to roughly 20%."  I thought that the alternative wording would be clearer.

Unfortunately, because I had the 20% figure at the back of my mind when I typed it, I actually made a 6 dB error when I quoted the figures anyway.  I meant to type "Some audio software treats -8 dB as 0 VU, while Avid defaults to -14 dB."

Either way, if you rely on defaults without calibrating your tools, you can expect errors.

Thanks all, I'm just getting around to reading these replies. My mixer set up has always been zeroed out or normalized. And I've dropped the files in question down in db's to see if their still distorted and it's unclear why but they still sound over modulated to me. I'm going to have to make some serious comparisons to the original files, when I have more time to mess around a little. Thanks. adam5000

 Adam, just for the record I regularly import Audio CD tracks. They always come it at 0 db levels and initially sound distorted, but lowering levels always makes them sound normal as they should - no borderline overmodulation after adjusting.

Thanks. I guess depending on the original track, sometimes it sounds worse than others.