Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!uwm.edu!csd4.csd.uwm.edu!info-high-audio-request
From: ggs@ulysses.att.com (Griff Smith)
Newsgroups: rec.audio.high-end
Subject: Re: What's up with RDAT?
Message-ID: <11578@uwm.edu>
Date: 30 Apr 91 12:57:41 GMT
Sender: news@uwm.edu
Lines: 45
Approved: tjk@csd4.csd.uwm.edu
Originator: tjk@csd4.csd.uwm.edu


In article <11521@uwm.edu>, winalski@psw.enet.dec.com (Paul S. Winalski) writes:
> In article <11436@uwm.edu>,
> ... the format doesn't record the entire digital signal, but allegedly
> the only information lost is stuff you can't hear, anyway, so it
> doesn't matter.  The same claim was made for the analog copy-protect
> signal notch when that was proposed, and testing by the NBS showed that
> the claim was false--the differences were trivially audible.

It's not the same thing at all.  The Phillips system probably deletes
signals that are below perception thresholds, the copy-protect notch
deleted a narrow bad unconditionally.

> I therefore remain a skeptic of Phillips's claims that their data
> compression doesn't affect the signal.

No argument, the compression affects the signal.  It would probably
be unintelligible to a modem.

> I suspect that the golden ears, who already bash RDAT and CDs for their
> signal infidelity, are going to have a field day with SDAT.

No argument here, either.  I would paraphrase it as "the golden ears,
who already imagine signal infidelity in RDAT and CD will have a
field day".  They will.  They will also refuse to compare straight
digital recordings with compressed recordings, which would confirm
that the differences are usually inaudible.  Instead, they will
compare SDAT with LP and then point out the obvious sonic clarity
of the latter.  If they do compare SDAT with CD, they will refuse
to do proper level matching because the extra components needed to
balance the output levels might obscure the clarity of the superior
medium.

> I'll take RDAT, thank you.

I'll admit to a nagging feeling that I'd like to have the whole signal
recorded, but it's not based on rational behavior.  When serving
as a test subject for hearing compressed digital sound, I was unable
to select any of the compressed signals reliably.
-- 
Griff Smith	AT&T (Bell Laboratories), Murray Hill
Phone:		1-908-582-7736
UUCP:		{most AT&T sites}!ulysses!ggs
Internet:	ggs@ulysses.att.com