AudioFormat Wars
By: Sheldon Khan
Before buying a new car, getting married, or adopting a
new audio format
it is wise to ask a few questions, peer under the hood, and ask
the advice of
someone you trust. Will the new format satisfy your needs not
only now but,
also in the future? Will it look (and sound) as good on all the
mornings after
you first met?
The analogue cassette is an old and trusted versatile
friend that went
with you on those morning jogs and cruised in the car with you on
Friday nights.
However, the powers that be, have declared our trusted friend to
be in the last
phase of the life cycle. It's successor must sound better, work
better, and
have new features such as a digital display for song titles.
There are
currently two formats competing to be the consumers next choice
for sound on the
go. They are Philips' Digital Compact Cassette (DCC) and Sony's
Mini Disc (MD).
What exactly is digital recording? The definition is, "An
electronic
format that is designed to duplicate sound, while affording
extremely accurate
control over any changes you might wish to make in the recording"
(Mclan &
Wichman,1988). In simple terms it means that the digital
circuitry samples the
signal and then reproduces what it has seen. The quality of the
recording
depends on the sampling rate of the machine. The sampled signal
is then encoded
to the tape or disc in 1's and 0's, just like a computer disk
drive would encode
information. However, the biggest advantage of digital recording
is the fact
that it eliminates tape "hiss" that is usually found present in
analogue
recordings.
In the Eighties, a Philips invention captured the
limelight. The
Compact Disc introduced us to a new era of digital sound, or
"perfect sound."
In the nineties another Philips invention has taken centre-stage,
the Digital
Compact Cassette (DCC). DCC is the marriage of the analogue
cassette to Digital
Audio. Together they form a union that combines perfect sound,
high convince and
greater versatility. " DCC is a medium on which audio information
is digitally
encoded and which reproduces CD quality sound" (Philips
Electronics, Sound &
Vision, 1995). A number of features have been incorporated into
DCC tapes and
decks to achieve CD like sound and convince. DCC decks can
locate a chosen
track on either side of the tape because track and time codes are
recorded on
the tape. This combined with autoreverse, which is standard on
all DCC decks,
makes track access effortless but, not as fast as a CD. Another
attractive
feature of DCC is the text mode. Text mode allows the deck to
display support
information about the recordings on the tape such as the album
title, a complete
list of track titles, names of the artists on each track, and
lyrics (displayed
in sync with the music). Television screens or remote control
units can also be
connected to the deck to display more extensive information.
The tapes have
recording and playback times of 60, 90, and 100 minutes. "The
well known
durability of cassettes is enhanced by the use of videochrome
tape: chromium
dioxide- or cobalt- doped ferric-oxide" (Philips Electronics,
Sound & Vision,
1995). With the new tape shell, the tape and tape drive wheels,
which are
exposed on the analogue tape, are concealed by a metal sliding
panel called a
"slider". The slider helps protect the tape from dirt and dust
which
contributes to tape breakdown. This along with the videochorme
tape and DCC's
digital error correction system help prevent tape dropout.
Numerous digital
first generation DCC to DCC copies can be made. Any further
copies (ie. 2nd,
3rd, etc generation) made from the first generation copy will not
be digital.
The biggest advantage that DCC has over the competition is its
compatibility
with its analogue predecessor.
Sony's Mini Disc is a miniature version of the compact
disc that comes
in a plastic shell like that of a 3 1/2 computer floppy. "Unlike
CD's,
MiniDiscs can be recorded using magneto-optical technology"
(Dmytryk, 1993, p.
62). Mageto-optical technology allows a MiniDisc to be recorded
on many times.
A MiniDisc is smaller than a DCC tape and has random track access
like a CD. It
also gives the user the capability to edit songs, and the order
that they appear
in on the disc. To record on a partially full disc, simply hit
Record, with no
concern for cueing. Recording starts immediately and the new
material is added
as a new track. It is also simple to remove dead air and
unwanted material.
The deleted time is added to the total time remaining on the
disc. All of this
makes it very easy to create your own custom compilations. The
MiniDisc, like
the DCC allows the user to make multiple first generation digital
copies. But
second and third generation copies will not be digital. One of
the biggest
advantages that MD has over DCC is it's small slim size and
durability. By
comparison the sharp edged DCC cassette seems a bit clunky and
less durable .
Both MD and DCC use data-compression techniques to
squeeze digital audio
data into a fraction of the space required by a CD or a Digital
Audio Cassette
(DAT). " DCC's Precision Adaptive SubCoding (PASC) achieves
slightly better than
4-to-1 compression. While Mini Disc's Adaptive TRansform
Acoustic Coding
(ATRAC) is slightly worse at 5-to-1" (Dmytryk, 1993, p. 65). Both
developers
justify the use of compression with these statements,
"The human ear only hears sounds above a certain loudness
(dB)
level, called the hearing threshold. The threshold of
hearing depends on
the frequency of the sound. Therefore, only sounds
above this
dynamic threshold need to be recorded."(Philips Electronics,
Sound & Vision,
1995)
Loud sounds can completely mask softer sounds that are
close in
frequency. Because our hearing is far more acute in the
mid-range than at
the high or low end of the spectrum, what you hear is
defined by the
frequency content during each time slice." (Dmytryk, 1993 p. 65).
In other
words no one will know the difference if certain frequencies are
missing.
What will all of this new technology cost the average
consumer? Well, a
Philips DCC deck cost about $600, pre-recorded DCC tapes cost
about $20, and
blank tapes cost about $8. While a MD player cost about $500,
the pre-recorded
discs cost about $20 and the blank disc cost about $10. Of
course as the
popularity of the format grows, the cost will drop.
Manufacturers are trying to give the public a more
durable and better
sounding medium for those of us that are always on the go.
However, since their
introduction about three years ago very few MD and even fewer DCC
players have
been sold. Some audio experts feel that the reason they have not
sold many
units of either format is because the average person thinks that
there is
nothing wrong with the sound quality of a good CrO2 (Maxell's
XLII) or metal
(Sony's CDit IV) analogue cassette. Many people still live by
the old saying,
"If it ain't broke, don't fix it." Manufacturers have built up
these new
formats as "the greatest thing since slice bread," in the hopes
of changing the
way people listen to music. Yet, the public has not jumped on
the band wagon of
either of these new formats. However, one thing is certain, the
days of the
analogue cassette are numbered.
It is only a matter of time before either MD, DCC or some
new digital
format such as the recordable CD takes the place of the analogue
cassette.
BIBLIOGRAPHY
Ballou, Glen. Handbook For Sound Engineers (2nd ed.). Indiana:
Sams, 1991.
Davis, Don & Carolyn. Sound System Engineering. Indianapolis,
Indiana: Howard W.
Sams & Co Inc, 1975.
Dmytryk, George. "Digital Debate." Electronic Musician, Vol 9
No.8, 1993,
August: 62-70.
Mclan, Peter & Wichman, Larry. The Musican's Guide To Home
Recording. Toronto:
Simon & Schuster Inc, 1988.
Robertson, Patrick. The Book Of Firsts. New York: Bramhall House,
1974.
Sony Home Page. www.sony.com. e-mail: webmaster@sony.co.jp
Digital Compact
Cassette. Philips Electronics N.V. (1995).
. Audio Format Wars
By: Sheldon Khan
Before buying a new car, getting married, or adopting a
new audio format
it is wise to ask. Digital
Audio. Together they form a union that combines perfect sound,
high convince and
greater versatility. " DCC is a medium on which audio information
is