Suggestions for easier clipping removal/repair

[JohnH]

I assume I'm like most users in that I try to set my recording levels as high as possible without clipping. But some sources have "loud bits" that are so loud, if you set the levels based on them, the rest of the recording is so low-gain that it's practically inaudible. (I've found that on a typical pop/rock album, I'll have about a half-dozen of these loud bits, maybe a few more if the snare drum is mixed high.) Thankfully, VinylStudio's manual click-repair feature, which I realize is not meant to fix clipping, does a pretty good job of fixing these "loud bits."

The problem is, you can't automatically scan for these loud bits. In order to find them, you have to keep the Equalization Curve window open while you're looking for spikes in the main window's waveform display, but the peak-level indicator is the only reason to have that window open while doing this. So you keep having to move the mouse from the Play/Pause button over to the other window's peak-level reset icon, over and over and over again until you find the exact spot where the clipping is.

So, here are my suggestions for this:

• There should be an easily-reached keyboard shortcut to reset the peak level indicator — I'd go with the comma key, personally.
• It might also be nice to have the peak level indicator in the main window, or even a separate-but-dockable window, especially if that would also allow you to make it bigger.
• Even better, if the program could optionally somehow highlight the spikes where clipping occurs with the current EQ and gain-adjustment settings, maybe by displaying them in a different color or line thickness, I wouldn't have to hunt for them at all.
• Maybe the biggest timesaver of all would be a "Stop-on-Clipping Mode," so that whenever you encounter clipping, playback stops with the cursor positioned right at the point where it occurs.

Again, I realize this is not what the program is intended for, but it does do a decent job of it, so I can't be the only one using it this way, can I? I'm not looking for a way to automatically fix clips, in fact I'd rather fix them manually using the existing functionality. I just want to be able to find and "zero in" on them with less effort.

Thanks and so on!

[Steve Crook]

I started out with the same general approach of trying to set recording levels as high as possible and re-recording because of clipping. Then I began to wonder why I was doing it. It made sense when doing analog recordings to tape where tape noise was almost always much worse than LP noise. But does it matter for digital?

Average LP surface noise is anywhere between -60 and -70db on good quality LPs, from a decent phono-pre -80 to -85db and a really good preamp will be -90db, an ADC probably closer to -100db. Tape was anywhere from -50db to -65db, so just about comparable to LP.

Upping the gain on the signal in VS will not reduce the effect of disc noise or anything in the chain as you'll be amplifying the noise as well and all the electronics are already so quiet you'd never hear them.

The upshot being that I gave up on fine tuning recording levels and have a setting that peaks up to about -4 or -5db. I use whole album, 0db normalisation (skipping track breaks) prior saving tracks to get levels as high as I can.


HTH

[Paul Sanders (AlpineSoft)]

Hi Steve,

The relevant term, in the digital domain, is dynamic range, and if you record at 24 bits you have a lot of that to play with, so yes, you don't need to squeeze the last drop out of it when setting the recording level.

It's a different story when recording at 16 bit.  Then, in the digital domain, you have 96dB of dynamic range to play with so you do have to be a bit more careful.

It's worth noting that normalising a 24 bit recording and then saving at 16 bit is quite a good way to do things, if you need to keep file sizes down.

John, I'll answer address your comments later today.

[Steve Crook]

Interesting. I'd not thought of it in those terms. I'll have to do some reading. If you have a link to somewhere as a starter that would be very helpful.

And I am doing 24/192 and saving at 16 bit.

[Paul Sanders (AlpineSoft)]

Hi Steve,

You can just Google the dynamic range for 16 bit and 24 bit audio.  That's all I did, in order to compose my answer.

[Paul Sanders (AlpineSoft)]

Hi John,

Re improved handling of clips, it's only actually necessary to worry about those introduced during the recording process.  If filtering introduces any, VinylStudio's Normalise function will put that right (which is why we recommended doing it last).

But I think we can do better with clips in the original waveform.  My current thought is to add an option to display them in the Corrections List (as an alternative to listing clicks) in the Cleanup Audio window, which would provide a convenient mechanism to step through them.

I also like your idea of using the click repair mechanism to repair them; I hadn't thought of that.

So I'll file this for now and revisit it when I have time.  In the meantime, do please feel free to continue the discussion.

[JohnH]

Thanks! 

Still, just to reiterate, I'm not trying to convince you to reimagine the whole product or anything major like that. Just having a keyboard shortcut to reset the peak-level indicator while in repair-mode would be a huge help, and at least for me, it could mean the difference between a somewhat-healthy wrist and serious carpal-tunnel syndrome.

[Paul Sanders (AlpineSoft)]

OK, noted

[Paul Sanders (AlpineSoft)]

We will implement this in V13.1.0, due out soon (as I keep saying!).  The shortcut key will be single quote (comma was taken).

[Paul Sanders (AlpineSoft)]

... and this did indeed get done

[JohnH]

Cool! Thanks for doing that! 

And I hope I don't come off as excessively greedy, but did you also implement that idea to identify the clips as such in the corrections list? I guess I didn't respond to that earlier (sorry!), but that actually would be really helpful too, especially if you could filter it or highlight them somehow.

[Paul Sanders (AlpineSoft)]

Not yet, but we do have plans.  Putting them in the corrections list has merit, I'll think it over.

[Lewis]

Gents,
nothing new but may be FYC.
Dynamic range (min/max crest factor) of your digitizations refers to the original/_source_ material specifically cut for your LP production.
Re: 96 dB (16 bit integer) vs 1528 dB (32 bit float).
 @@I try to set my recording levels as high as possible without clipping. But some sources have "loud bits" that are so loud, if you set the levels based on them, the rest of the recording is so low-gain that it's practically inaudible. (I've found that on a typical pop/rock album, I'll have about a half-dozen of these loud bits, maybe a few more if the snare drum is mixed high.)@@
Just record at 32 bit float (no matter @ 48/96/192, etc). You can and must repair clipping (if any) by handling WAV files no harm will come to your original waveform, no quality gets compromized.
Normalization is tabooed for good guys.

[Paul Sanders (AlpineSoft)]

I agree with most of that, but just to say, I know of no ADCs that work at 32 bit precision.  24 bit is the most they can do so there's no point recording above that.

So record with a fairly conservative recording level and you can then boost it before saving your tracks if you wish.  If you get clipping while recording, you are stuck with it.

[Lewis]

Gents,
if things were to be done twice, all would be wise.
I've just left out one thing for certain. The 32 float quantization (if supported) enables clip removal, de-clipping (post-editing) flawlessly.
Paul, though Korg DS-DAC-10R inherently (PCM4202) provides for the 24 bit integer only, when in use, it realy can do recording @ 32bit float.