[Arny Krueger]

"Harry Lavo" wrote in message
. ..

"Arny Krueger" wrote in message
. ..

While most of what Arny says here is correct (and it is nice to be able to
agree with him for a change) there is one specific statement that
addresses your hypothesis that I take issue with:

"Commercial CDs that sound like crap, do so because of other steps in the
process."

Arny doesn't provide a basis for his conclusion, but a few years ago there
was a long discussion on Usenet (I believe RAP but I am not certain of
that) different CD's from different plants sounding different, and the
role of the producer and/or engineer in giving final approval of the
process. The general thrust was that the differences were likely the
degree with which error correction was required, and the degree to which
on-disk jitter needed to be corrected.

Both issues can and are effectively dealt with by a good player. Some early
players had specific problems when there were erorrs, particularly with
discs that were substandard at the time they were played. Some of these
problems became latent when disc quality improved, and became apparent again
when we started trying to play CD-Rs on these legacy players.

BTW when people talk about jitter at the CD pressing level, they aren't
necessarily talking about jitter as it is usally applied to audio signals.
Jitter at the disc level can show up in the audio more like missing data.


There was also some discussion that the problem was worse when plants were
being provided with analog tape and doing their own production mastering
(thus making the analog and digital quality of their own D/A's an issue).

IME, the worst thing about a pressing plant doing their own mastering would
relate to artistic and production timing issues. They are much more likely
to try to make a go out of a bad situation that would be corrected by
finding a different master, earlier in the process. They are less likely to
put a lot of time into tweaking the transfer until they had a good sounding
result.

As Arny says, this was perceived to have been more of a problem in '80's /
early '90's than at the time of the discussion.