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From: 5121cdd@houxm.UUCP (C.DORY)
Newsgroups: net.audio
Subject: Re: differences in sounds of CD players
Message-ID: <670@houxm.UUCP>
Date: Wed, 11-Jan-84 10:54:51 EST
Article-I.D.: houxm.670
Posted: Wed Jan 11 10:54:51 1984
Date-Received: Thu, 12-Jan-84 01:00:12 EST
References: <773@drufl.UUCP>, <372@hound.UUCP>
Organization: Bell Labs, Holmdel NJ
Lines: 44

Boys, Boys...are we forgetting all the anolog circuitry in the CD player?
There are about as many unique realizations of these analog circuits
(i.e., anti-aliasing filter, reconstruction filter, line-level circuitry, etc.)
as there are currently available CD players.  Not to mention, some
manufacturers utilize over-sampling techniques, both digital and analog
filtering, etc., etc...  If, of course, you believe the rave reviews in
Audio, Stereo Review, and High Fidelity, these varying executions of CD
players make no difference whatsoever -- remember, these mags live off the
advertising revenue from audio-equipment manufacturers.  The CD has received
the biggest media hype the audio industry has seen. (Has anyone seen a bad
review in one of these mags lately?)

There are other IMPORTANT aspects to audio equipment performance than
simply THD distortion specs and magnitude response (erroneously called
"frequency response") alone.  What about time-domain response?  We are
attempting (through the recording chain) to recreate musical performances
so that we can enjoy them time and time again.  Music is NOT time independent --a bassoon sounds like a bassoon when its frequency and time components
are reproduced accurately.  (These are not usubstantiated claims --
much of the recent work of Deane Jensen - Jensen Transformers, John Bau -
Spica Loudspeakers, Mile Nestorovic - Nestorovic Loudspeakers, John Meyer -
Meyer Sound Labs, Patrick Duran - Horus Music, John Curl, (the list goes
on...) is focused on TIME DOMAIN accuracy of their components.

It is very important, also, to note what type of music is listened to in
making subjective judgments in audio equipment.  No offense, but there
is little "true stereo" information in current Rock/Pop and most of
the Jazz recordings -- Supertramp - "Crime of the Century" and 
Pink Floyd - "Dark Side of the Moon" and "The Wall" are notable exceptions,
however.  Most of the Pop/Rock and jazz recordings are made with
the recording console as an integral "instrument" in the compositions
and, therefore, these recordings are multi-mono.  True stereo ONLY comes
from simple miking techniques (two and at most three mics with the
best results from coincident techniques).

What I'm getting at, is that unless that your source is of unimpeachable
quality (I know of few), your system is accurate (well?), you have an
excellent listening room (noisy fridge, flimsy walls?) there is no way
you can make many of the subjective judgments that I see made here on the
net and in the mags.



                                      Craig Dory -- AT&T Bell Laboratories
                                                         Holmdel, NJ