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Old 22nd May 2019
Lives for gear
FabienTDR's Avatar

Verified Member
You specifically mention the CD format. Afaik, Red-book doesn't allow the a-law or u-law I mentioned above. But it has this ominous pre-emphasis flag, also long forgotten:

Some CDs are mastered with pre-emphasis, an artificial boost of high audio frequencies. The pre-emphasis improves the apparent signal-to-noise ratio by making better use of the channel's dynamic range. On playback, the player applies a de-emphasis filter to restore the frequency response curve to an overall flat one. Pre-emphasis time constants are 50µs and 15µs (9.49 dB boost at 20 kHz), and a binary flag in the disc subcode instructs the player to apply de-emphasis filtering if appropriate. Playback of such discs in a computer or 'ripping' to wave files typically does not take into account the pre-emphasis, so such files play back with a distorted frequency response.
Of course, only very few players support this.

IMHO the above comes closest to your observation. I really don't assume that you are hallucinating, don't get me wrong pls. I just think there are many other potential causes.