wjm@whuxk.UUCP (08/18/83)
Greg's challege is the right way to answer the questions about CD's. As I've
said in earlier articles posted to net.audio, the CD MEDIUM has the potential
for excellent sound, although some of the earliest CD's (especially those from
some of the "major" record companies who are also noted for foisting digitally
mastered recordings with an "audiophile recording" sticker on the shrink wrap
and $2 added to the price) did not live up to the medium's potential.
As for lists of Good and Bad CD's, both "Audio" and "Stereo Review" have listed
CD's which their record reviewers have auditioned - Some have gotten outstanding
reviews (mostly Telarcs or recordings made by similar techniques with a minimum
2 or 3, number of microphones), while others, generally multi-miked productions
have gotten properly canned.
I'd still like to know (which is what started this discussion on the net) how
to tell if CD player A is better/the same/worse than CD player B and what
measurements that can be verified in the lab correlate to sound quality -
Based on the reviews I've seen so far, it seems that the Kyocera DA-01 seems to
be one of the better ones.
I can't believe that ALL CD players will be equal in sound quality - there are
too many manufacturers with different philosophies out there (let's get the best
sound we can and *&%$$%% the price - e.g. Nakamichi, Linn, etc., let's provide
the most sound per dollar - Hafler, Ohm and let's put out some cheap trash
and compromise on the sound - you know who they are) and that's going to show
up in CD players as well.
As I've said before, and I'll say it again - I don't know if ringing at 1KHz
correlates with CD player performance, but it is something that can be measured
in the lab. My point is WE NEED QUANTITATIVE MEASURMENTS FOR CD PLAYERS.
As for the MC vs MM debate, in general most high end cartridges are MC's which
means that those manufactures who said let's make the best cartridge we can
and BLEEP the price have gone that route - in spite of some technical drawbacks
(like the need for a head amp or transformer) due to its better frequency
response, separation, and insensitvity to preamp loading.
I think it is these factors that result in the "better sound" of high-end
MC cartridges (many of the same factors apply to the few MM cartridges like
the Grace F9 Ruby) which has been verified by A/B tests.
Returning to the idea of A/B tests - Linn set these up at the Summer Consumer
Electronics Show last month in Chicago (source 9/83 "Stereo Review") to compare
CD vs LP recordings using their high end Sondek/Ittok/Atis turntable/arm/cartridge
system.
With the records they selected, the LP's were preferred to the CD's by the
delegates at the show. It would be interesting to repeat this test with
Telarc material - I suspect with a good CD player the panel wouldn't be able
to tell the difference, especially if the LP's were dbx encoded to reduce
surface noise.
Not only do these results say how good CD's are, they also show how good LP's
can be with modern equipment, so let's enjoy both forms!
Bill Mitchell
Bell Laboratories - Whippany, NJ
(whuxk!wjm)
Disclaimer ... The opinions expressed here are my personal ones and are not
necessarily those of my employer, Bell Laboratories.michaelk@tekmdp.UUCP (Michael Kersenbrock) (08/19/83)
In reference to the CD vs Linn (analogue) test that Linn did. . .
Some of you may have noticed the Linn ad in Audio magazine that quotes some
of those golden-eared folk that tested the CD vs. their turntable. One
of them said something like "the CD sounded better that I thought it
would but ...". I think this is extraordinary of Linn to publish that
quote in their ad, because it points out very dramatically and graphically
that the deck was stacked, and the results preordained.
The results could be valid even if the "test" wasn't because,
some CD *discs* ARE rather poor. What the ad tells me is that Linn is
aware that they are in big trouble. They are acting in what appears to
be in desparation awful early in the "battle".
Also note that the ringing seen in both in the 1Khz square wave CD
reviews and even more so in MC cartridge reviews is not 1Khz ringing,
but more like 20 Khz ringing in response to the step function presented
by the 1 Khz *square wave* test signal. I agree that we need numerical
means to tell CD players apart -- in as much -- we are now starting
to have some of the same problems of telling apart amplifiers that
have THD's of 0.001% and 0.0008%.
By the way, when these (listening) tests are done, are they using
new LP disks being played for the first time or are these that have
been played & handled for 5 years (and perhaps cleaned of dust a time
or few over the years, etc) when compared with a CD? (where 5 years of
*continuous* playing wouldn't touch the disk although the player may get
a bit tired).
Mike (an obvious CD owner) Kersenbrock
Tektronix Microcomputer Development Products
Aloha, Oregon