[net.audio] Beta Hi-Fi Rebuttal

5121cdd@houxm.UUCP (C.DORY) (12/27/83)

The new Beta Hi-Fi concept is truly the best thing that has happened
to videophiles since color TV, melding high-quality video and audio
into a single system which is, afterall, upward compatible with the
standard Beta system.  This is, however, not to say that Beta Hi-Fi
surpasses, or even equals, other recording technologies.  First, let's
look at how Beta Hi-Fi does in comparison with the audio cassette deck,
its nearest competitor.  By itself, the Beta Hi-Fi technology boasts
only 60dB of S/N (internal noise reduction, seemingly similar to dbx,
is used to obtain the advertised 80dB S/N of the units on the market)
so it is only fair to compare the S/N specs to a cassette deck with
noise reduction -- a good cassette deck with dbx will also boast S/N
of around 80dB: a tossup.  As for frequency response, we also have a
tossup: both machines are fairly flat to 20K Hz at -20VU, however, as
recording level increases, the high frequency response of BOTH
Beta Hi-Fi and cassette decks go to pot.  As far as distortion goes,
both systems introduce the same order of magnitude of THD into the
music, however, in using the metal (type IV) formulations in cassette
tape, this can be reduced somewhat.  Therefore, the only significant
difference between audio cassette decks and Beta Hi-Fi is the
Wow & Flutter with the Beta Hi-Fi performing better.

Now, for those with enough chutzpah to compare Beta Hi-Fi with a
pro open-reel mastering deck.  The only Beta Hi-Fi I have had direct
experience with is the Sony SL-2700 -- a fine consumer machine.
However, mini jacks, can you believe it, MINI JACKS are used for mic
inputs and headphone outputs -- this is fine for Walkmen and the like
BUT NOT RECORDING EQUIPMENT.  Good quality mic cable WILL NOT
fit into the mini-jack plug housing, therefore you must use an
adaptor of some form, forcing extra weight to be supported by the
jack itself...get my drift?  As well, the mic inputs are unbalanced
so if you want to use them with high-quality condenser mics (which
normally require an external power supply to polarize the element
and power the electronics) forget it without a line-matching transformer
or external mic pre-amp.  In fact, an external mic pre-amp is not a
bad idea since the mic pres in the SL-2700 aren't too hot.  As far
as specs go, the SL-2700 can't hold a candle to a reasonable open-reel
deck, much less to a Studer or Nagra.  For example, my (modified)
Technics RS-1500US half-track machine has a flat (+0, -3dB)
frequency response from 30Hz to 32KHz!! (at 15ips, 0VU re. 250nW/m)
The S/N (with pro dbx) is well in excess of 80dB, and the
Wow & Flutter is 0.015%.  In use, the SL-2700 seems to have been
designed by Astro-Boy (busy control panel) -- I wouldn't want to
have to depend on finding the correct knob in the dark.

Overall, I hope I've made my point that the Beta Hi-Fi is great for
watching "Raiders..." with good-quality sound or for recording
a simulcast to appreciate the simule -- but if location recording
is your game, spend your $1250 on an open-reel deck and a dbx unit.


                                    Craig Dory -- AT&T Bell Laboratories
                                                       Holmdel, NJ

rmd@hpcnoa.UUCP (01/02/84)

#R:houxm:-65800:hpcnoa:30200007:000:458
hpcnoa!rmd    Dec 30 14:25:00 1983

I disagree with the statement or implication  that cassette decks are as
good as Beta HiFi.  dbx really  increases the  sensitivity of a cassette
deck to  misalignment  and head  wear.  You have to spend a lot to get a
cassette deck with adequate frequency  response and then they never seem
to match the manaufacturers  specifications.  Also, music passed through
ANY noise reduction system never sounds quite the same as the original.

Rick Dow
hpfcla!rmd

5121cdd@houxm.UUCP (C.DORY) (01/04/84)

Again, the point is missed -- remember that the Beta Hi-Fi uses a companding
scheme very similar to (I assume) dbx.  Also, look at how dbx Type II
noise reduction works -- frequencies above 10K Hz do not effect the RMS
detection so mistracking (pumping) is reduced (i.e., head wear and
misalignment are not a big factor).  This, however, is not true with
dbx Type I (professional) noise reduction, for optimum results flat
frequency response is required +-1 dB.  In practice, I find Dolby B
(and even Dolby A - professional) much more objectionable than dbx.
Dolby noise reduction is very level sensitive -- overall record and
playback levels must be within 1 - 2 dB to avoid mistracking.  This is
why Dolby B recordings are not as transportable as advertised -- record/
playback electronics from tape deck to tape deck are not closely matched.

I agree that no noise reduction is better -- for absolute sonic purity.
However, as always, we are dealing with a set of compromises -- I
personally hate tape hiss. dbx eliminates this problem while only
paying the piper a small amount.

                                        Craig Dory  --  AT&T Bell Laboratories
                                                             Holmdel, NJ