Admin at 07:43, 21 June 2010

2010-06-21T07:43:38Z

← Older revision		Revision as of 01:43, 21 June 2010
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	Use of an analysis tool such as SoX, which reports exact sample values, including phase and channel, is a more precise way to compare the contents of CDs one doesn't have on hand.		Use of an analysis tool such as SoX, which reports exact sample values, including phase and channel, is a more precise way to compare the contents of CDs one doesn't have on hand.

			[[Category:Ripping and analysis]]

Admin: Created page with 'When ripping a CD, Exact Audio Copy (EAC) reports the peak levels ("loudest" samples) present on each track. These values are often used to distinguish different [[mastering]…'

2010-06-06T18:59:09Z

Created page with 'When ripping a CD, Exact Audio Copy (EAC) reports the peak levels ("loudest" samples) present on each track. These values are often used to distinguish different [[mastering]…'

New page

When ripping a CD, [[Exact Audio Copy]] (EAC) reports the peak levels ("loudest" samples) present on each track. These values are often used to distinguish different [[mastering]]s of a single release.

Under most circumstances, differences in EAC-reported peak values are virtually certain to mean the pressings in questions have different audio content -- the exception being those rare occasions where a change in the CD's [[index points]] places a peak value in a different track on the disc. But identical peak values are '''not''' a guarantee of identical mastering, for several reasons:

* EAC's percentages are much lower precision (0.0% to 100.0%) than the actual 16-bit samples on a CD (-32768 to +32767). Each tenth of a "percentage point" can cover any of over sixty actual sample values.
* Peaks cannot distinguish releases with phase-reversed channels, because EAC does not report whether a peak value is positive or negative.
* Peaks cannot distinguish releases whose channels are swapped, as EAC reports the highest value in the entire track regardless of channel.
* Some masterings are normalized or compressed such that most or all tracks on the release have a "peak" of 0dB (100.0%).

Use of an analysis tool such as SoX, which reports exact sample values, including phase and channel, is a more precise way to compare the contents of CDs one doesn't have on hand.

EAC peak levels - Revision history

Admin at 07:43, 21 June 2010

Admin: Created page with 'When ripping a CD, Exact Audio Copy (EAC) reports the peak levels ("loudest" samples) present on each track. These values are often used to distinguish different [[mastering]…'