"Oversaturated" Extracted Audio

Alix wrote on 8/26/2003, 11:09 AM
I am a new user of Vegas (and any audio editing product) and am just learning, so please excuse my rampant ignorance. I use Vegas for audio because I like working with multiple tracks.

Recently, I extracted a series of CD audio tracks from a commercially-produced orchestral soundtrack. (I'm editing these for my personal use -- whoever ordered the soundtrack was high on something.) The problem is that the WAV files are what I'd call oversaturated, which I know is NOT the right term. The levels bleed past the acceptable range...and I'm so embarrased that I don't know the right terminology.

Is there a way that I can correct this problem after extraction, or control the extraction to avoid it?

I appreciate your advice. Thanks.

Alexandria

Comments

MJhig wrote on 8/26/2003, 11:53 AM
>>>The levels bleed past the acceptable range...<<<

Are you saying the levels peak above 0 dB? I'm not seeing this. If so is the track and main buss fader set to 0 dB and there are no plug-ins enabled in either also?

MJ
Chienworks wrote on 8/26/2003, 2:41 PM
I think you mean clipping, which is when the peaks hit 0dB and are flattened. Are you seeing this in the timeline when you look at the tracks (before any processing)? Are there areas where it looks like the peaks have been sliced off to produce flat lines? If so, then that's the way the CD was mastered. The ripping (extracting) process does not alter the signal in any way, so what you get is what was on the CD. SonicFoundry sells a Noise Reduction plugin that also offers clipped peak restoration and it can help a lot in this situation. It's a tad pricey, but you can try the demo for 15 days before deciding to buy it or not.

If you don't see the peaks cut off in the original clips then you've probably got a volume slider in Vegas set too high somewhere. You can adjust the volume in several places, including the track header, in each individual audio clip, on busses, and on the master control. If any of these are set higher than nominal level then you'll be increasing the level and possibly introducing clipping.
Alix wrote on 8/27/2003, 12:23 PM
Yes, the peaks are clipped at the tops. I was wondering myself if it was the CD, because the sound is "fuzzy" at parts. (This is Disney's Pirates of the Caribbean soundtrack). You can see what one WAV file looks like (I just included the top half, given that it is stereo) at:

http://www.alixnorth.com/tmp/ClippedPeaksOnExtractedAudio.gif

That's without processing. If this doesn't match what you're describing, let me know.

I really appreciate you helping me with the terminology. I need to educate myself more than a little bit in this arena! Also, thank you for the information about the noise reduction filter; I will look into that.

Alexandria
Alix wrote on 8/27/2003, 12:30 PM
Yes, the levels peak above 0 dB...thanks to Chienworks, I now understand that I'm talking about clipping.

I went ahead and extracted some tracks from other CDs with similar booming music (oh, I know, my audio vocabulary is stunning...not!) and I did not have anywhere near this amount of clipping occuring. So, yes, it appears to be the way the CD was mastered...bummer.

Thanks for responding!

Alexandria
Chienworks wrote on 8/27/2003, 2:02 PM
Sorry we couldn't perform a miracle for you. That's rather disappointing that Disney couldn't do a better mastering job. Their audio department is supposed to be a very top-notch operation.
Alix wrote on 8/27/2003, 4:06 PM
Well, I really appreciate knowing what's going on, because at least I can stop beating my head against the wall. :-)

My theory is that they really rushed the soundtrack out the door. I know that they didn't finish the film until the night before the late June premiere at Disneyland. The soundtrack is in the most bizarre order I've seen, but even more noticably, the names of the tracks do not match the contents in any conceivable way...thus my thought that this was fast and dirty. Maybe they'll expand and remaster it later.

Thanks again.
drbam wrote on 8/27/2003, 5:53 PM
>>http://www.alixnorth.com/tmp/ClippedPeaksOnExtractedAudio.gif<<

Well it looks terrible! Like many of the current "loud is better" mastering disasters. At any rate, its easy to see why it sounds bad - it is!

drbam
Geoff_Wood wrote on 8/27/2003, 8:47 PM
... though clipping itself has nothing to do with 'loudness' , it may have been a by-product of incompetent 'RMS normalisation'.

geoff