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- Xref: sparky comp.sys.atari.st:13770 rec.audio:12495 sci.skeptic:16422
- Newsgroups: comp.sys.atari.st,rec.audio,sci.skeptic
- Path: sparky!uunet!sun-barr!ames!sgi!wdl1!spl1.spl.loral.com!trw
- From: trw@spl1.spl.loral.com (Tim R Witort)
- Subject: DAT Stuff ( was sampling and human hearing range )
- Message-ID: <1992Sep14.190857.25275@wdl.loral.com>
- Sender: news@wdl.loral.com
- Organization: Loral Software Productivity Laboratory
- References: <BuG1wq.85E@world.std.com> <JT0yqB3w165w@tsoft.sf-bay.org> <+qwn34l.payner@netcom.com>
- Date: Mon, 14 Sep 1992 19:08:57 GMT
- Lines: 34
-
- A couple of erroneous comments have been raised about DAT technology:
-
- 1) You can't make a digital copy of a CD due to the copy protection.
-
- FACT: You CAN make a direct digital copy of a CD at the standard
- 44.1kHz sampling frequency onto a DAT cassette (as long as
- your CD player has digital outputs). What you CAN'T do is
- make a digital copy of a DAT recording from one DAT deck to
- another if the Serial Copy Management System (SCMS) is
- used by the DAT machine and the recording was made from a
- CD at the 44.1kHz sampling rate. This prevents digital
- copying of something that was recorded from a CD. This, of
- course, doesn't stop anyone from making a million digital
- copies of a CD from the CD itself.
- DAT recordings made at the 48kHz sampling rate may be copied
- digitally DAT to DAT.
-
- 2) The DAT sampling rate is 48kHz.
-
- FACT: True, but not the whole picture. DAT samples at 48kHz for
- recordings made from anything but a direct CD source. Some
- professional DAT decks allow the sampling rate to be set
- at 44.1kHz even if the source is not a CD. This allows a
- CD "Master" to be made that could be transfered to CD with
- no DA/AD conversion. Someone pointed this out.
-
- FACT: Many DAT decks also provide a "long play" recording mode which
- reduces the sample quantization from 16 bit to 12 bit, the
- sampling rate from 48 kHz to 32kHz, and the tape speed is
- halved. This doubles the time capacity of a DAT cassette and
- reduces the frequency response to 5 - 14,500 Hz. All other
- specs remain practically identical.
-
- -- Tim
-