Audio disortion

Jelleke · Member Joined: 12 Sep 2004 Location: Belgium

Hi,

I was restoring a VHS and i found out that on some places there is a little disortion.
Not that bad but i was wondering if their is a good filter and setting to remove it?
I already tried different ones in soundforge but i can't get out of it.
Here is a sample:
http://users.telenet.be/skaterke/disortion.mp3

Thanx!

Cornucopia · Posted: Aug 31, 2007 15:10

Could be analog distortion, could be digital distortion (clipping). If the former, can't do much (bandwidth-sensitive compression & filtering--very tricky), if the latter and very light you could used CoolEdit/Audition's "Clip Restorer". Otherwise, you're SOL and should start over, paying better attention to each point in the chain re: Gain structure (not too quiet to add noise, not too loud to create distortion).

Scott
_________________
"You don't know what you got, until you lose it".--John Lennon

Jelleke · Member Joined: 12 Sep 2004 Location: Belgium

problem is that the disortion is on the tape and not on my recording...
it's analog VHS to digital DV

Cornucopia · Posted: Sep 01, 2007 18:30

If it's on the (original VHS) tape, it's analog distortion. This means your choices are extremely limited.

Maybe you can use a filter/dynamics package like I mentioned. What it should do is this:

1. Split up the signal into multiple frequency bands (anywhere between ~5 and 1024, depending on complexity).
2. Analyze the peak volume/level of each of the bands.
3. If a band gets TOO LOUD, WAY TOO QUICKLY (or sometimes just TOO LOUD), have the filter automatically drop the level by a certain amount. (helps with clipping)
4. Alternately, also have adjacent "spillover" bands be attennuated as well. (helps with IM distortion)
5. Alternately, also have harmonic bands (whole multiples) be attennuated as well. (helps with TH distortion)
5. Of course, recombine the bands into a single channel once manipulated.

Even then, it won't be much better. That's why I mentioned starting over from scratch...
(Sure hope this wasn't the only copy of a single live performance)
May have to just live with it as-is.

Scott
_________________
"You don't know what you got, until you lose it".--John Lennon