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replaygain, intersample overs, and reconstruction stages
SiriusB
post Nov 30 2007, 23:25
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My understanding of intersample overs is that they are waveform peaks occuring between samples, that aren't reconstructed to their 'true' amplitude by consumer gear because the samples on either side of the peak are too close to 0dBFS already. These intersample peaks can be as much as 6dB 'over' 0dBFS, or more commonly a few dB over. They 'happen' when a production is monitored using peak meters that only measure peak values of the samples, rather than the levels of the reconstructed waveforms. So if an engineer slams the sample peaks repeatedly up to near 0dB, as part of the loudness wars, the file will still show as 'legal' using the inadequate meter. It will be 'illegal' in terms of the level of the true waveform peak levels. Consumer gear and consumer software D/A stages don't 'know how' to reconstruct peaks that are >0dBFS, outputting distortion instead.

Assuming I've got this right (tell me if not), does lowering sample peak level a few dB in the digital domain -- e.g. by applying negative replaygain values -- prior to D/A reconstruction increase our chance of recovering the 'true' waveform at output? Or is that accurate peak shape lost forever?

Another way to phrase this is, how do consumer D/A stages normally reconstruct peaks that occur between samples, and why can't they do it when such peaks are over 0dBFS?

This post has been edited by SiriusB: Nov 30 2007, 23:38
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Posts in this topic
- SiriusB   replaygain, intersample overs, and reconstruction stages   Nov 30 2007, 23:25
- - greynol   QUOTE (SiriusB @ Nov 30 2007, 14:25) Assu...   Nov 30 2007, 23:54
- - mixminus1   TC Electronic has some very good papers on various...   Dec 1 2007, 00:39
- - Kees de Visser   QUOTE (SiriusB @ Dec 1 2007, 00:25) Anoth...   Dec 1 2007, 08:25
- - SebastianG   QUOTE (SiriusB @ Nov 30 2007, 23:25) Thes...   Dec 2 2007, 10:02
- - SiriusB   Check the papers by Aldrich and by Lund. 6dB is...   Dec 3 2007, 06:53
- - SebastianG   Oh, it's even worse! Theoretically, you ca...   Dec 3 2007, 17:45
|- - knutinh   QUOTE (SebastianG @ Dec 3 2007, 17:45) Oh...   Dec 7 2007, 23:12
|- - SebastianG   QUOTE (knutinh @ Dec 7 2007, 23:12) QUOTE...   Dec 8 2007, 09:42
- - SiriusB   My questions are ultimately about reconstruction. ...   Dec 5 2007, 19:20
|- - greynol   QUOTE (SiriusB @ Dec 5 2007, 10:20) And d...   Dec 5 2007, 19:43
|- - SiriusB   QUOTE (greynol @ Dec 5 2007, 13:43) QUOTE...   Dec 5 2007, 21:44
- - greynol   If you reduce the level of the data before it hits...   Dec 5 2007, 22:07
- - DVDdoug   I don't know what "pro gear" does to...   Dec 5 2007, 22:30
|- - greynol   QUOTE (DVDdoug @ Dec 5 2007, 13:30) I don...   Dec 5 2007, 22:57
|- - SiriusB   QUOTE (DVDdoug @ Dec 5 2007, 16:30) I don...   Dec 5 2007, 23:03
|- - greynol   QUOTE (SiriusB @ Dec 5 2007, 14:03) I nor...   Dec 5 2007, 23:35
|- - SiriusB   QUOTE (greynol @ Dec 5 2007, 17:35) QUOTE...   Dec 5 2007, 23:57
|- - Vitecs   Interesting subject. My 2 cents: QUOTE (SiriusB ...   Dec 7 2007, 15:58
- - greynol   I'd really have to see screenshots of what you...   Dec 6 2007, 00:04
- - SiriusB   That's the sort of commercial CD example I...   Dec 7 2007, 17:54
- - knutinh   1. Nyquist was right. In theory, a waveform of ban...   Dec 7 2007, 22:54
|- - benski   QUOTE (knutinh @ Dec 7 2007, 16:54) 5. Co...   Dec 7 2007, 23:05
|- - greynol   QUOTE (benski @ Dec 7 2007, 14:05) Your s...   Dec 8 2007, 22:33
- - greynol   It's quite easy to show a sync pulse in CEP/Au...   Dec 7 2007, 23:06


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