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From: winalski@psw.enet.dec.com (Paul S. Winalski)
Newsgroups: rec.audio.high-end
Subject: Re: What's up with RDAT?
Message-ID: <11521@uwm.edu>
Date: 29 Apr 91 12:46:01 GMT
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Approved: tjk@csd4.csd.uwm.edu
Originator: tjk@csd4.csd.uwm.edu

In article <11436@uwm.edu>,
km456265@longs.LANCE.ColoState.Edu (Kevin Melsheimer) writes:
|>
|>Has anyone heard any information about the new digital format that
|>is coming out sometime this summer?  Is the new RDAT system supposed
|>to be as good as existing DAT systems?

The new format is not RDAT (rotating-head DAT).  It is SDAT (stationary-head
DAT).

On the chosen tape dimensions, SDAT cannot record at the same density as
the existing RDAT.  It cannot deliver enough bandwidth to support recording
a full two channel, 16-bit digital signal at the 48KHz or 44.1KHz sampling
rates currently in use for digital audio.  Instead, the format performs
sophisticated data compression on the signal, in essence, throwing away
those parts of the signal that are psychoacoustically inaudible.  Thus, 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.  I therefore remain a skeptic of
Phillips's claims that their data compression doesn't affect the signal.
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.  I'll take RDAT,
thank you.

|>  How will the new Philips
|>deck analog end stand up to normal tape players (the new dcc format
|>I've heard will be able to play normal audio cassettes) What will
|>the dynamic range be like?
|>

Shouldn't be much different from any other analog cassette player.  I
suspect they'll use the same head and other analog technology that they
use in their current cassette players.

--PSW