[net.audio] A-B Tests

heuring@boulder.UUCP (Vincent Heuring) (05/11/85)

I've been following the traffic dealing with A-B tests, CD vs analog, etc.
as well as reading the high-end and mainstream audio mags. While I have
always been a fan of J. Gordon Holt's Stereophile as the best of the
golden ear mags (-: he usually agrees with me :-) it amuses me that
Audio is the first to include regular reviews conducted by reviewers
who not only use A-B testing, but quote the degree  of statistical 
significance of the results. Ever notice how the gear in polished
walnut cases often gets described as rich, smooth, warm, while
gear in black anodized Al sounds harsh, lacking in warmth, and 
has a hard, glassy high end. Sigh.

Let's face it, folks, we are at a watershed period in hifi. Less and
less are we going to be concerned with frequency response, distortion,
and other flaws in the *reproduction* of recorded sound. Forget
what Doug Sax and the others say who listen with their wallets, or who
were trained in analog audio and can't hack digital (Carver ?).
That digital signal is going to creep it's way forward and backward
in the signal path; back to the a-d converter in the mike, forward
clear to the dac imbedded IN THE OUTPUT TRANSDUCER (right, folks, the
digital signal path will extend clear to the speakers.) Then we will 
be able to forget our psycho-acoustic concerns about  mike cable
hum, crummy mixdowns, aging master tapes, virgin pressings, off-center
holes, clicks, pops, skips, flutter, wow, hum, freq resp, distortion,
control noise, shot noise, ofc wire, etc etc etc . 

Then maybe we can concentrate on appreciating the music. Our concerns
about the reproduction equipment will center on things like room
equalization (how about a small lapel mike which dynamically
optimizes the listening environment). Then the arguments between
the traditionalists and the modernists might center around questions
like whether it is better to reproduce the music exactly as recorded,
shape it to the listening environment, or strip it all the way back
to its anechoic state and restore ambience as desired.  Perhaps some day
many compositions will be available in their anechoic form only, and
the golden ears will be selling filter coefficients and reverb information.

I for one look forward to the day when the only noise I hear when
listening to my recordings is the rustling of scores.

			Vince Heuring


"..ya don't need a weatherman ta know which way the wind blows.."

mohler@druxu.UUCP (MohlerDS) (05/14/85)

This sounds like an arguement that Digital Audio Magazine outlined
last month. If you believe this (dac in the speaker) stuff that is
up to you. It may make sense to move the dac up towards the mike
and it may make sense to have one very high quality dac that your
pcm recorder and cd feed into (ala sony's new set-up), but a dac in the
transducer...not soon! Digital Audio Mag. went so far as to infer that
there would be a power dac that would supply the current to the transducer
which sounds to me like the author in the magazine does not know of what
they speak. I am a firm believer that digital audio is here to stay, but
I am also believe that an analog amplifier is impossible to get around.
Lets face it, a transducer as we know them requires current and an amp
has to provide it. Putting the amp and a dac in the speaker will never
gain industry backing and if someone has the poor judgement to build
one commercially it will go the way of the powered Advent, Four channel
and dino's (the big critters not the car).

			David S. Mohler
			AT&T - ISL @ Denver
			!druxu!mohler

mohler@druxu.UUCP (MohlerDS) (05/15/85)

For those of you that sent me mail regarding digital transducers,  Thankyou.
I have read some articles on the subject and while they look hopefull, 
my opinion is still, not soon!
They may be the next significant improvement, however I think it will be
years before you can buy one. (Usually such new items are shown at the June
CES about 2-3 years before you can buy one, last year there were no such
displays. Maybe this year? I doubt it, but I'll look.) My point was
regarding our current transducer technology and making the system driving
it more digital, which if not impossible is highly unlikely. Once again
thanks to those who brought research and references to my attention.

			David S. Mohler
			AT&T - ISL @ Denver
			!druxu!mohler