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Path: utzoo!watmath!clyde!burl!ulysses!allegra!bellcore!decvax!tektronix!hplabs!hp-pcd!hpfcmp!rjn
From: rjn@hpfcmp.UUCP (rjn)
Newsgroups: net.audio
Subject: CD Reflections
Message-ID: <15100001@hpfcmp.UUCP>
Date: Wed, 2-Jan-85 03:07:00 EST
Article-I.D.: hpfcmp.15100001
Posted: Wed Jan  2 03:07:00 1985
Date-Received: Sun, 13-Jan-85 07:35:24 EST
Lines: 99
Nf-ID: #N:hpfcmp:15100001:000:5082
Nf-From: hpfcmp!rjn    Jan  2 00:07:00 1985


[] re: observations of a new CD owner (fairly long: ~100 lines)

I recently purchased a CD player (Sony CDP610ES), 20 discs and thought I
might share my initial  impressions  with you.  Prior to this  purchase,
most of my  listening  consisted of FM and some 1/4-in.  tapes made from
LPs.  Although I have an extensive LP collection, I don't play them very
often,  due to the  hassles,  not the least of which is having to endure
the LP ritual every 20 min.  or so.

====================== The PLUSES of CD listening ======================

NOISE:  There  is no  rumble,  clicks  and  pops;  no hiss if the CD was
digitally mastered; no pre-groove echo or print-thru.

DISTORTIONS:  There  is no wow or  flutter  if  digitally  mastered;  no
compression  'breathing'; no warp wow; no  inner-groove  distortion.  It
used to very much  annoy me when I found  that the  producer  had put my
favorite  selection  on the last cut of the side - a non-issue  with CD.
There is also no tracing  distortion  on loud  passages  (I don't have a
$500 cartridge).

WEAR:  No worry about the CD wearing out eventually.  No need to wait 24
hours before replaying (to allow the groove walls to recover).  No worry
about  stylus  wear.  The first time you listen to an LP, you know "this
is as good as this disc will ever be"; with a CD "it will always be this
good".

CLEANING:  I suppose CDs  eventually  require some cleaning, but nothing
like the discwasher/zerostat (or worse) ceremony LPs require.

CONVENIENCE:  I now  change  discs  once  per HOUR and can use a  remote
control to skip  around and program the disc, not to mention  being able
to answer the phone without  running over to the  turntable  first.  CDs
are  also  portable.  Using a  "Discman"  type  portable  player  is not
inconceivable.

TAPING:  If I  decide  to make  some  tapes  from my CDs, it will be far
easier than with LPs.  Cueing is trivial and I can prevue the entire cut
to determine the optimum record level, with no wear worries.

PACKAGING:  I don't have to stock special anti-static record sleeves to
replace the LP's paper ones many LP makers use.

HANDLING:  Although I intend to be as careful with my CDs as I have been
with my LPs (some of which are 20 years  old), I have far less  paranoia
about the inevitable little mishaps.

==================== The MINUSES of CD listening =======================

ENVIRONMENT  - CDs have pointed out to me just how noisy  refrigerators,
forced  hot air and  home  computers  are.  I may have to  'upgrade'  my
residence :-)

EXPEN$E - Yes CDs are costly  today.  I expect  that they will come down
to LP  prices  within  two  years.  Even  at  today's  prices,  I'm  not
complaining.  If  anyone  offered  a  "lifetime"  LP, I would pay the CD
price for it.

PHASE  SHIFT - If the 11 uSec  delay  represented  by  multiplexing  two
signals  (each at 44KHz) is not  present in the  ENTIRE  record/playback
chain, it may be an issue.  I recently read a source which  claimed that
this is at the  threshold  of human  phase  detection.  Of course,  this
would only be perceptible on earphones, since speaker placement distance
variation  easily  exceeds  11 uSec.  I haven't  done  enough  headphone
listening to know if I can hear any phase effects.

HIGH END FIDELITY - If we assume (and perhaps we shouldn't)  that all we
need to capture are complex signals composed entirely of symetrical sine
waves whose  highest  overtone is 20KHz, a (2x)  digitizing  rate in the
vicinity  of 40KHz just won't do.  For  example,  suppose we  digitize a
pure  20KHz   signal  at  40KHz,   and  happen  to   capture   only  the
zero-crossings.  How  much  information  does  that  get us?  We need at
least 3x  digitizing  (60 KHz) to  reconstruct  a pure sine  wave, and I
suspect that actual music demands that we use at least 4x (80 KHz).

Although  my hearing  is no longer  good  enough to have any  complaints
about CD sound, some of you golden ears are evidently hearing SOMETHING.
Keep complaining; it should be possible to develop a fully compatible 88
KHz (or better) CD that would play at 44KHz on existing equipment and at
a higher rate on a newer generation  machine (one simple way would be to
put the alternate  samples on the other side, read by a second laser and
digitally sync'd).

========================== The bottom line =============================

* I can finally listen (at home) to the MUSIC and not the MEDIUM.

* The CD system has the lowest hassle coefficient in audio.

* For a first implementation of a new consumer music technology, CD is a
  remarkable  technical   compromise.  The  first  music  cassettes  and
  4/8-track  cartridges  were a step  backward.  CDs are far superior to
  all other mass-produced media (I don't consider DBX disc/tapes and PCM
  tapes to be mass-produced).  CDs are probably on a par with audiophile
  LPs (all things considered) and have superior ease of use.

Bob Niland                                           [hplabs!]hpfcla!rjn
Hewlett-Packard                    Ft. Collins                        CO