jurb wrote: "And actually it is not really for noise reduction. When the source has low HF content it is not using enough bits and people
complained it sounded grainy or whatever, some such adjective. This was before CDs actually, it is built into all CD players, unless there
are some that are cheaper than even I can imagine. "


_______
So CD really DID emphasize compactness
over fidelity in the design stage! So much
that the sampling rate and bit depth were
'just adequate', especially at higher frequency
content where more waves fit between the
samples and represented by same available
bits.

So by boosting above, say, 10 or 12khz
those highs would take more advantage
of available bits, and then the de-emph on
the player is supposed to check TOC for
a pre-Emph flag and apply de-Emph, like
turning down a treble control with a
standardized curve, like RIAA on vinyl
records.

Some of my older CDs are kind of trebley,
not at all grainy, but top heavy. When I
turn my treble knob a little left of center,
it smooths out the whole sound. These
are same CDs that Exact Audio Copy
does not detect pre-emphasis on. So the
engineer probably didn't know how to flag
it in the TOC, or forgot, or flagged it
improperly. ???