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[Alécio Costa - Brazil]

Hi friends
This has been discussed at the the DUC and at Brad;s room a long time ago.
I am converting 48k/24 stereo files to 44k/24 bits with a few plugs and my limiter is set for -0.2dB just to be in a safe zone.
So I open a new PT TDM session to do a 44k/24 to a 44k/16 final conversion with Power Dither and now levels are hot as hell, peaking -0dB.
Funny that this does not happen with every properly limited celing song file.
Is this a problem with PT's internal mathing?some round errors due to 48/44.1 mathing?
I never have these problems when working  at 44k/24 files.
Is there a safer ceiling so as to avoid this?
Hope I do not have to limit twice
Thanks in advance

[turtletone]

It's protools. The SRC is being done after the limiter and the filters of the SRC are raising the level slightly. It's just a poor SRC. Better to SRC and then limit.

[dcollins]

Al Dave Collins Mastering Pulse Techniques LLC bbalin Newbie Offline Posts: 8 Re: Bump level with ceiling limited bouncing I think the dominant effect is that your limited source material contains intersample peaks : the waveforme exceeds 0 dBFS but these peaks are not visible in the discrete sample values. When resampling at a different sample frequency the peaks or part of them will be sampled and will clip if working in 24 bit fixed point arithmetic. Intersample peaks can be as high as 5..8 dB. If you have an RME audio card you can use digicheck to display these peaks before SRCing. In Cool Edit Pro /Adobe Audition the waveform is interpolated between samples and these peaks are visible as well. Reduce levels by 3..6 dB or use floating point audio files. Boris Alécio Costa - Brazil Hero Member Offline Posts: 791 Re: Bump level with ceiling limited bouncing THanks friends! Same results with ceiling at -0.2 or -0.1db. Would it be better if the CD Fs was 44k instead of 44.1k? DC wrote: "If you drop everything 3dB, you can even accommodate the worst case signal, but -0.3 is probably more like it...." more like....? Alécio Costa Studio High-end Mastering, Music Production http://www.aleciocosta.com Listen to my album at: http://www.audiostreet.net/aleciocosta MySpace: http://www.myspace.com/aleciocostamasterizacao dcollins Hero Member Offline Posts: 2815 Re: Bump level with ceiling limited bouncing Al Dave Collins Mastering Pulse Techniques LLC Print Pages: [1]   Go Up « previous next » R/E/P Community > R/E/P > R/E/P Archives > Brad Blackwood > Bump level with ceiling limited bouncing   SMF 2.0.19 | SMF © 2021, Simple Machines | Terms and Policies XHTML RSS WAP2 Site Hosted By Ashdown Technologies, Inc. Page created in 0.083 seconds with 19 queries.

[bbalin]

I think the dominant effect is that your limited source material contains intersample peaks : the waveforme exceeds 0 dBFS but these peaks are not visible in the discrete sample values.
When resampling at a different sample frequency the peaks or part of them will be sampled and will clip if working in 24 bit fixed point arithmetic.
Intersample peaks can be as high as 5..8 dB.
If you have an RME audio card you can use digicheck to display these peaks before SRCing.
In Cool Edit Pro /Adobe Audition the waveform is interpolated between samples and these peaks are visible as well.

Reduce levels by 3..6 dB or use floating point audio files.

Boris

[Alécio Costa - Brazil]

THanks friends!
Same results with ceiling at -0.2 or -0.1db.
Would it be better if the CD Fs was 44k instead of 44.1k?

DC wrote:

"If you drop everything 3dB, you can even accommodate the worst case signal, but -0.3 is probably more like it...."


more like....?

[dcollins]

Al Dave Collins Mastering Pulse Techniques LLC Print Pages: [1]   Go Up « previous next » R/E/P Community > R/E/P > R/E/P Archives > Brad Blackwood > Bump level with ceiling limited bouncing   SMF 2.0.19 | SMF © 2021, Simple Machines | Terms and Policies XHTML RSS WAP2 Site Hosted By Ashdown Technologies, Inc. Page created in 0.083 seconds with 19 queries.