[net.audio] The "progress" of audio

rentsch@unc.UUCP (Tim Rentsch) (08/18/85)

In article <olivee.390> Greg Paley writes:
>
>It's amazing how little tape hiss is to be heard on these recordings.
>All of them were pre-Dolby masters.  Also amazing is the general
>sense of weight and clarity of bass response of the 1958 "Das
>Rheingold" - it puts to shame a number of recordings made within the
>last year.

This brings to mind a demonstration/experiment I attended recently.
Forgive me if the point of the story takes a while to get back to the
preceding paragraph.

What happened was this:  I attended a seminar given for an engineering
audience, about music reproduction.  The seminar had set up a stereo
system (it included some dynaco mono tube amps, some british (dynamic) speaker
I had never heard of, a Meridian CD player, an ordinary turntable, and
a good cartridge;  the person arranging the seminar, at least, thought
that the equipment was all good and had gone to some effort to assure
such.)

Now, while billed as a seminar, it was actually more of an experiment.
We started off listening to two recordings of music, for about 5
minutes each, one on an LP and the other on a CD.  The first piece of
music was "The Firebird" (in each case the same music was played on
both the LP and the CD, though not necessarily from recordings of the
same performance).  "The Firebird" recordings were, in fact, made at
different times, and I had never heard either performance before.
After the two recordings were played, the audience was polled (by show
of hands) as to which of the two recordings they preferred.  The
results:  about 45 preferred the LP, about 12 preferred the CD.

The seminar speaker talked a little bit, then repeated the procedure
with different recordings.  The results were about the same in each
case, with between 45 and 50 preferring the LP, between 5 and 15
preferring the CD.  (Some people came late and/or abstained.)  For the
most part each trial was done comparing the same music but from
different performances;  only the last two trials were done from
recordings made at the same time.

The second to last trial was done using recordings made at the same
time, indeed using the same microphones and the same master tape.
(Alas, I do not remember the particular piece of music.)  The
difference was that the master tape was done digitally but with 18 bit
samples rather than the 16 bits that CD uses.  More people preferred
the LP (which was done off the 18 bit master tape) than the CD, but the
results were less decisive.  (To my ears, the digital effects were
still present, but there was somehow more detail -- flutes in
particular sounded more like real flutes.)

The last trial was done comparing the "West of OZ" recording, comparing
the CD to the direct-to-disk recording, which were done using the same
microphone feed.  Comparable to the earlier trials, many more people
preferred the LP to the CD.  (I don't have exact numbers for any of
these -- but the results I report are within 5 of the actual numbers
taken.)

(Before someone flames me to say that this experiment isn't valid
because it isn't double blind, or single blind, or whatever, I would
like to say that I make no such assertion.  I am not trying to convince
anybody of anything -- I am just reporting for your information and
amusement.  So don't bother, OK?)

Finally, to the point of the story.  The seminar was about comparing
the state of the art in audio today with the state of the art in audio
years ago.  The "Firebird" recording that we compared to CD and found
overwhelmingly in its favor:  when do you suppose it was recorded?
1958.  And I don't just mean that the master tape was recorded in 1958.
The vinyl was pressed in 1958.  In each case but the last two, the LP
was from an earlier performance of the same piece of music, and done at
least 15 years earlier than the CD.  

And it wasn't just about digital -- the seminar speaker discussed other
so-called advances in audio:  transistors versus tubes, recording tape,
microphones used, microphone placement, ....  On the subject of
recording tape, the speaker contended that recording tape of 20 years
ago is better than recording tape of today.  (He did not attempt to
prove his point, though he did give a short anecdote which illustrated
it.)  But he did give an explanation of mechanism, to wit:  first,
recording tape of today has larger dynamic range, but that also has
implications about stability -- if the particles can be moved to align
with less magnetic field, then they are more likely to be affected by
stray magnetic fields;  and second, tapes today have a very finely
controlled particle size, with the result that hiss has a
characteristic frequency (a consequence of the particle size) -- earlier
tapes, where not as much was known and where the particle size varied a
lot, had hiss frequency that was more uniformly distributed, with that
hollow background sound rather than the bacon frying SSSSSSSS that is
typical today;  remember, it's not just the S/N ratio of the hiss, but
also the frequency distribution of the noise.

All in all, I wonder if the best we can say about CD is that we can
compare it to LP's made 25 years ago.

cheers,

Tim Rentsch

rfg@hound.UUCP (R.GRANTGES) (08/20/85)

[]
What school was that?
Your story reminds me of the seminar by Dr. Rolf Von Zeitel I arranged
(with some help) for the joint EE/Physics faculties at the University
of Minnesota some years ago. Title was something like My memories of
the Manhattan Project. We had an overflow crowd at the Student Union.
Seems it turned out that Dr. Von Zeitel, thick cherman accent and all,
was a paint salesman from south St. Paul.
I wonder whatever became of good old Rolf.
Anyhow, ever listened to a good mono lp? Terrific S/N right? Wow!
What bass!!
Was your lecturer really a paint salesman?  (rhetorical question)

-- 

"It's the thought, if any, that counts!"  Dick Grantges  hound!rfg

rentsch@unc.UUCP (Tim Rentsch) (08/23/85)

In article <1310@hound.UUCP> rfg@hound.UUCP (R.GRANTGES) writes:
>[]
>What school was that?
>Your story reminds me of the seminar by Dr. Rolf Von Zeitel I arranged
>(with some help) for the joint EE/Physics faculties at the University
>of Minnesota some years ago. Title was something like My memories of
>the Manhattan Project. We had an overflow crowd at the Student Union.
>Seems it turned out that Dr. Von Zeitel, thick cherman accent and all,
>was a paint salesman from south St. Paul.
>I wonder whatever became of good old Rolf.
>Anyhow, ever listened to a good mono lp? Terrific S/N right? Wow!
>What bass!!
>Was your lecturer really a paint salesman?  (rhetorical question)
>
>-- 
>
>"It's the thought, if any, that counts!"  Dick Grantges  hound!rfg


The school was Caltech.  The seminar was done as part of a series for
Electrical Engineering types.

The lecturer was James Boyk, a musician by profession.  (He has some 
recordings available in which he plays piano.)

rfg@hound.UUCP (R.GRANTGES) (08/25/85)

[]
Right, probably was a paint salesman on the side as well.

-- 

"It's the thought, if any, that counts!"  Dick Grantges  hound!rfg