Tweet
I was reading this method for removing crackle on Clive's FAQ - Transferring LPs to CDR: Some Advice at(http://homepages.nildram.co.uk/~abcomp/lp-cdr.htm).
He describes a method for removing really bad crackle from an album... Here it is...
"I recently came across a suggested method of decrackling that is definitely worth passing on. I take no credit for this method; I first saw it described on the AudioForums website by someone calling themselves "Younglove". Here is the original thread; I have no idea how long the AudioForums threads stay online.
The procedure briefly is this:
1.Get a noise fingerprint from the WAV file to be decrackled. In other words, find a section that contains only noise and light crackle, but no music.
2.Use the noise fingerprint to do a noise reduction over the whole file, but keeping just the noise (rather than the music minus the noise). You need to do a fairly brutal noise reduction (eg. 100% in CoolEdit). What you end up with is the noise, the light crackle, and a bit of the music.
3.Save the noise that's just been isolated, either in a file or a clipboard.
4.Run a declick operation over the noise. Be fairly aggressive, so as to find all the crackle. You now have the noise minus the crackle.
5.Mix-paste the noise that you saved in step 3 over the result of the declick, but invert the saved noise that you're pasting. This causes the noise to cancel out, leaving just the crackle, but inverted.
6.Now mix-paste that inverted crackle back into the original file. Because the crackle is inverted, it cancels the crackle in the original file.
It really does work rather well, but remember that it only works for background light crackle; it doesn't deal with big pops and clicks.
So how does this work? My view is that the reason decrackling is so hard to do is because the clicks that constitute the crackle are of low amplitude, and are easily lost within the surrounding music: this makes identifying them very difficult. Once you've isolated just the background noise & crackle, the click detection algorithms have a much easier task, so they find the genuine clicks more successfully. "
*************
I just ordered a copy of DC-ART32 (it hasn't come in the mail yet - maybe tomorrow!), and was wondering if you could do this using DC-ART32. I have the demo version and was looking around in the manual, but was unable to find anything resembling "inverting" the signal before paste/mixing it back in.
I have read tips for DC-ART32 regarding running the declicker a couple of times using slightly different settings on really scratchy recordings, but this method does sound very interesting and I'd love to try it.
If anyone can point me in the proper direction I would be very thankful.
thanks!
bobk
He describes a method for removing really bad crackle from an album... Here it is...
"I recently came across a suggested method of decrackling that is definitely worth passing on. I take no credit for this method; I first saw it described on the AudioForums website by someone calling themselves "Younglove". Here is the original thread; I have no idea how long the AudioForums threads stay online.
The procedure briefly is this:
1.Get a noise fingerprint from the WAV file to be decrackled. In other words, find a section that contains only noise and light crackle, but no music.
2.Use the noise fingerprint to do a noise reduction over the whole file, but keeping just the noise (rather than the music minus the noise). You need to do a fairly brutal noise reduction (eg. 100% in CoolEdit). What you end up with is the noise, the light crackle, and a bit of the music.
3.Save the noise that's just been isolated, either in a file or a clipboard.
4.Run a declick operation over the noise. Be fairly aggressive, so as to find all the crackle. You now have the noise minus the crackle.
5.Mix-paste the noise that you saved in step 3 over the result of the declick, but invert the saved noise that you're pasting. This causes the noise to cancel out, leaving just the crackle, but inverted.
6.Now mix-paste that inverted crackle back into the original file. Because the crackle is inverted, it cancels the crackle in the original file.
It really does work rather well, but remember that it only works for background light crackle; it doesn't deal with big pops and clicks.
So how does this work? My view is that the reason decrackling is so hard to do is because the clicks that constitute the crackle are of low amplitude, and are easily lost within the surrounding music: this makes identifying them very difficult. Once you've isolated just the background noise & crackle, the click detection algorithms have a much easier task, so they find the genuine clicks more successfully. "
*************
I just ordered a copy of DC-ART32 (it hasn't come in the mail yet - maybe tomorrow!), and was wondering if you could do this using DC-ART32. I have the demo version and was looking around in the manual, but was unable to find anything resembling "inverting" the signal before paste/mixing it back in.
I have read tips for DC-ART32 regarding running the declicker a couple of times using slightly different settings on really scratchy recordings, but this method does sound very interesting and I'd love to try it.
If anyone can point me in the proper direction I would be very thankful.
thanks!
bobk
Comment