LINGUIST List 4.783

Sat 02 Oct 1993

Disc: Technology: CD vs Minidisc

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1. Eric James Adolphson, Technology: CD vs Minidisc

It always seems strange to read discussions on recording equipment in Linguist.
The main reason I say this is it is often strangely misinformed. Here's some
history of the different digital recording formats, and the pluses and minuses.

First, true digital recording for mastering is done using a computer with DSP,
and records onto a hard disk. At their most primitive levels, they are sound
cards for IBM, Amiga, and Mac that allow one to record and play back music or
voice, usually two channel stereo with minimal processing and editing. At their
most expansive, they can record 16 channels with 256 discrete tracks per channel
and can allow direct waveform editing on any track. They can offer many levels
 of
of signal processing including compression, notchband filters, rocking,
equalizers, MPX and Dolby, the list goes on. These systems allow for complete
sliding and matching of tracks. These are also very expensive, $20,000 +. After
the editing, the product is recorded onto true DAT, which is then used to master
CD's.

Now, the main expense of DSP editors is the DSP chips and the hard drives. Full
recording studio systems use four 1.2 GB SCSI II wideband hard drives to give
about one hour of recording time at 16 channels. Digital audio eats hard drive
space. The advantage is the control of data on hard drives. If you are really
serious about control over recording and editing, you should use one of these
systems to record the original, do whatever editing you wish, and the trans-
cribing. (You can play back at whatever speed you wish, and compare multiple
discreet segments both audibly, and visually by comparing waveforms. Then
master down onto DAT.

A good basic system for doing this kind of thing is the Sunrize DSP editor for
Amiga. Similar systems are available for MAC and IBM. Figure, however, that
you will pay around $1500 for the DSP card, and another hard drive of at least
300MB.

DAT, CD, MiniDisc and DCC.

CD's, as I'm sure everyone is aware, is a permanent media. It cannot be recorded
to. There is some confusion with CD's and Magneto-Optical drives. Magneto op
Optical is a recordible CD. They are very expensive at present, but might well
be the removable hard drive of the future.

True DAT is not available for the general public. It has been available over
seas for years, but, because it allows for multiple generations of copies, it
was blocked in this country by the recording industry who feared limitless
CD quality tape piracy. Again, editing on these systems is primitive, but that
is not what they are for. They are simply a recording system. There are some
"editing" DAT systems out there. They operate similarly to older mult-deck
tape recording systems, with all of the expertise of operation.

To get around the fears of the recording industry, Phillips produced the DCC f
format, and Sony, the mini-disc. Both use a compression format, mainly to
cause loss of signal over generation copying. Thus, they were allowed to offer
them in the US. Of the two, DCC has better fidelity. Again, they are not for
editing-- they are simply meant to record pre-edited audio.

Now, DAT (Truest fidelity), DCC, Mini-disc, and good old analog tape are all
fine media for copying. If you want full editing in the digital domain, you
use a computer with the appropriate DSP board and a big hard disc.

 Eric Adolphson
 Senior Technician
 Taylor Video/Audio

(Taylor is a full production audio video facility, recording in a fully
digital environment.)