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Gear / Technical Help => Post-Processing, Computer / Streaming / Internet Devices & Related Activity => Topic started by: BlindGuyEars on June 01, 2017, 04:29:30 PM

Title: Can Severe Clipping be Corrected?
Post by: BlindGuyEars on June 01, 2017, 04:29:30 PM
HI folks.

I've "fixed" or at least lessened the nasty sound of some short clipping before, using Sound Forge.  However, I have a more extreme example here.  I tried recording Tool with Hooke Audio's Hookeverse, a pair of earbud/mics that stream to a smartphone. Sorry for the lossy format, but the HookeAudio app doesn't yet save to uncompressed PCM.

Could anything be done to save or improve this using something like iZotope RX 6? I don't have anything more sophisticated here than the aforementioned Sound Forge.

https://www.sendspace.com/pro/dl/hewebg (https://www.sendspace.com/pro/dl/hewebg)

I've always read and believed that once things clip digitally, that's it. You can't go back or fix it. But, I thought I'd see what the experts here think.

Note: the recording is binaural, so actually sounds decent on headphones, except for all the distortion that is. :)

Thanks for any suggestions.
Title: Re: Can Severe Clipping be Corrected?
Post by: bombdiggity on June 01, 2017, 05:01:08 PM
Izotope RX declipper can work wonders.  I've never tried it on something thoroughly fully clipped (and hope I don't have to) but it is fine on short passages and random spikes. 
Title: Re: Can Severe Clipping be Corrected?
Post by: strangerinusall on June 03, 2017, 06:54:35 AM
Check your inbox...  ;)
Title: Re: Can Severe Clipping be Corrected?
Post by: anr on June 03, 2017, 09:52:43 AM
https://wetransfer.com/downloads/c2fcf442043767ccadb550a47ca8a7cd20170603135101/7e8afd090919702734130eabb403f10020170603135101/16839d
Title: Re: Can Severe Clipping be Corrected?
Post by: Ben Turnbull on June 03, 2017, 10:11:28 AM
Izotope RX declipper can work wonders.  I've never tried it on something thoroughly fully clipped (and hope I don't have to) but it is fine on short passages and random spikes.

I don't mean to be a nattering nabob of negativity here, but my experience w/Rx and clipping is that it doesn't work well when there's massive stretches or where there's significant overs that would ordinarily peak at... say, 3-4 dB above 0.  Then again, I'm not sure what software is out there that would.  The algorithms seem like they can reshape a clip flat top to some reasonable curve, but the bringing it all down to under the 0 line sometimes does weird stuff to that area already residing below 0, resulting in some pretty muddy crud.  I  have had success with moderate and isolated instances, as Bombdig- says.

We are well advised to watch those peaks for a reason.  If you have had great success, perhaps there's a setting that I'm not seeing or familiar with.

my 2c.
Title: Re: Can Severe Clipping be Corrected?
Post by: bombdiggity on June 03, 2017, 01:56:44 PM
I don't like the automated settings but go through manually since I'm typically dealing with a random spike or two.  One consideration in settings seems to be to make sure you reduce the overall level of the area more than it needs to reduce the peak in redrawing it.  Otherwise it is applying compression of some sort.  I often play with the settings on the passages involved a few times until it draws something that looks right.  These days I have an eye for what looks like it should work so not so much trial and error.

Billy Hart gave me fits last night...  The whole thing was peaking -12 or less other than some "bombs" he periodically dropped (at least a couple of which had to be way over, even with the limiter on).  So once again I'll need it in a spot or two.  Hopefully they'll clean up nicely...  It sure was great though.