Wave Corrector Users

renowden · Joined: 15 Oct 2007 Posts: 68 Location: Bristol, England

1. When you normalise and/or channel balance, does it take the peaks after track boundaries and corrections have been applied or before - the answer will determine whether I ought to removed the big glitches at start and end (due to turntable switching) before processing?

2. It may be only imagination but if I remove a large section using cut and splice, it seems all my track boundaries shift. Is that the case, if so I should do the final track boundaries after all other cleaning up?

Question

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Cheers,

Rick Parsons

Bristol, England

Derek · Posted: Sun Dec 09, 2007 11:03 am Post subject: Re: And a couple of questions

renowden · Joined: 15 Oct 2007 Posts: 68 Location: Bristol, England

Thanks - I will look at point 2 more closely if I suspect anything. It was only a feeling and may have been because I didn't set them very accurately the first time around.
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Cheers,

Rick Parsons

Bristol, England

renowden · Joined: 15 Oct 2007 Posts: 68 Location: Bristol, England

I have investigated this more closely and this is what I have discovered.

I knew I had a particularly difficult album to process, so what I did was to very carefully mark the beginning of each track using the resolution on it's finest 0.1 second and setting the boundary within one tick mark of the first note (0.02 second), a bit tighter than I would normally do.

I then manually went through the entire album removing the glitches. There were quite a lot of bad ones as I suspected and many I had to remove using cut and splice. Fortunately the rhythm was generally quite slow and it didn't affect it noticeably. There were 67 in all over an album of 43 minutes and 13 tracks. No cut was very large, usually 50 to 100 frames caused by bad clicks and stylus bounces.

Then when I looked at the track markers again, track 13 start was some distance from where it should have been - nearly 0.6 second BEFORE the start of the music and getting progressively less for the earlier tracks. I can't tell if the end markers also moved

So the movement of the track marker forward when sound data is being removed suggests that it is not that the compensation is being neglected but rather that it is being a little over done on each occasion.

I have saved the files in this state, though being 480MB, they would be difficult to send. I hope that I have provided sufficient information to enable you to reproduce the problem.
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Cheers,

Rick Parsons

Bristol, England

Derek · Posted: Wed Jan 09, 2008 4:07 pm Post subject:

Yes, thanks for this report.

From your description, I now understand what is going on. The problem occurs because track boundaries in Wave Corrector are constrained to be at multiples of 588 samples. (This is so tracks are always an exact number of audio CD frames). Therefore when you use cut and splice to remove a few samples, all the track boundaries after the cut are adjusted to maintain the 588 sample requirement. In practice, this means that boundary position will be 'rounded down' to the next 588 multiple position. (Note, 588 samples represents one seventy fifth of a second.)

If, as you have done, you make multiple cuts in a file, then each one will result in a rounding down operation. And therefore, you'll get an accumulation of these rounding down errors - which is what you're reporting.

Unfortunately, it would be quite difficult to amend the code to avoid this. So I think the best advice is to make all your cuts before setting your track boundaries.

I'm sorry that my previous answer did not explain this. Imust have forgotten about this aspect of the code. Sad

all the best and thanks again
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Derek Higgins
Wave Corrector Developer
http://www.wavecor.co.uk

renowden · Joined: 15 Oct 2007 Posts: 68 Location: Bristol, England

Thanks - I'm glad is was easy to explain. No problem at all adjusting them afterwards, I was just worried that something might be going awry.
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Cheers,

Rick Parsons

Bristol, England

Glenn · Joined: 28 Feb 2005 Posts: 212 Location: Toronto, Canada

Derek wrote:

renowden · Joined: 15 Oct 2007 Posts: 68 Location: Bristol, England

Now that is not something that I had noticed. I will be interested in What Derek has to say about that.
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Cheers,

Rick Parsons

Bristol, England

Derek · Posted: Wed Feb 20, 2008 9:28 pm Post subject:

Yes, well spotted!

I've been investigating this and, as reported, normalisation is not applied to the cross-fade region of a cut. I'll have to fix this in the next release. There should be a beta out within a week or two.

Thanks for the report.
_________________
Derek Higgins
Wave Corrector Developer
http://www.wavecor.co.uk