Hello again Keith -
Thanks for the frank and honest reply. This is what I thought was going on,
but I didn't think anyone else realized it. What I mean is, maybe I am some
kind of idealist, but I firmly believe that systems can be analyzed and
designed better. My background is industrial design. I have never worked in
that field, but my schooling has apparently had a great impact on me. We
used to consider it our job to analyze whole systems before we could design
"a better mousetrap."
In audio, it seemed to me after extensive reading about stereo and imaging
and psychoacoustics that we have studied all of the parts of the elephant
but never put them all together in a cohesive big picture of what it looks
like or how it works. Binaural, yes, quite simple, you want the signals that
impinged on the binaural head to be channeled directly to your ears, and you
should hear the same acoustic event that happened to the dummy head. Stereo,
not so fast.
An engineer once said to me, when he got as frustrated as you and AE with my
theories, that "stereo just happens." That is a pretty good summary of the
state of the art!
If I may be as frank with you as you have with me, your admitted differences
in taste in speakers between - well among the three of us - was the reason I
wrote the What Can We Hear thread. The most maddening aspect of all of audio
is that we have not yet winnowed down the field by pure experimentation and
experience to one concept of what it is that your speakers should be like,
what they should do in making the sound that was recorded. Nor can you sit
two audiophiles down in front of a given system and have them agree that
this is the ultimate. In short, still no concensus whatsoever after all
these years, as you have said. I find this frustrating and unproductive. I
believe that there IS a goal, a paradigm, possible, but that an audio
reproduction event is also a NEW event, a new work of art if you will, and
not JUST a replica of the live event. I have made a few recordings now that
I enjoy more than the live event I was recording!
Boils down to my desire to have you do some "hard-nosed" listening to your
system and see how it really does compare to live. I think it might survive
the first three EEFs, but fail on the spatial one. I mean, even in the sweet
spot maybe you can hear some annoying artifacts of such a high direct field
that do not happen live. In my experience (hey, I once sat with Gordon Holt
at a demo of the Wilson WAMM in southern California at a big dealer) the
Wilsons are too hot on the direct sound, compared to live music, which is a
primarily reverberant field. The imaging runs from one speaker to the other,
and that is it. If there is an extreme left or right instrument, it comes
from that speaker, an effect that annoys the crap out of me. My first
requirement is that the sound go outside the speaker boxes. Too hot a direct
field will collapse the sound to the speakers and in between, and effect
that is not like live. This is just one effect you may notice if you listen
with a really hard-nosed realistic attitude.
Now, I am sorry that I did not answer some of your previous questions above,
when you have taken the time to write back. I mean no disrespect, so I will
try, and fortunately you have repeated some of it here, so I will respond
below:
"KH" wrote in message
...
I don't think you want to know "how stereo works", you appear to want some
theory that ties everything together, and that when adhered to results in
*A* correct, optimally realistic reproduction. There is no such single
solution, and there never will be for the myriad reasons presented to, and
apparently ignored by you. A few:
1. The recorded signal does NOT contain all the information from the
original space, and short of an infinite number of mics and channels,
never will. This is a simple fact.
OK, I understand what you are getting at here, but my smartass answer would
be, where did it go? The microphones heard just as much of the audible
happenings when recording in stereo as the binaural head would have. With
the binaural head, the problem we found was that the head could not turn
while listening, so there was an IHL problem, but there was no "missing"
information, it was just not presented in quite the same way as we can
listen live. The stereo microphones, no matter which pattern except for AE's
nemesis the close up multimiked affair, record the direct sound, and the
early reflected and some of the reverberant, just like you would if you were
there. There is enough information going into your two ears at the time, so
why not into the microphones and therefore out of the speakers at the time
of playback?
What you are getting at is found in Blauert, in fact right on the cover,
where it shows a zillion small speakers around the subject's hotseat during
an experiment in which multiple microphones recorded an event of the sound
arriving at a single spot, and there is an attempt to reproduce a "you are
there" impression, kind of like binaural only with speakers and for this one
listener only. Amar Bose told me of an experiment in Eindhoven where Philips
had used about 120 channels and some signal processing in an anechoic
environment to cause the reproduction sound fields to be more of a duplicate
of the original and have no interference from the listening environs.
2. The stereo effect is an *illusion*, and always will be, again, unless
multitudinous speakers are used to replay the recording from equally
multitudinous mics.
3. There is no objective reference for realism. There is only
*preference* for various implementations of the illusion.
Yes... well... as I agreed earlier, the recording is a new work of art,
using the original as a stepping off point, but I think there are ways we
can study the whole process and get closer, if not all the way there, which
I believe is a false goal. Architects agree about the design goals of a good
hall, but audiophiles have no agreement on the design goals of a good
speaker/listening room system. This is because most think that stereo is a
"trick" that may fool your ears into hearing an illusion of the live event -
kind of like binaural.
I use Wilson Audio Sophia II's as my reference. Dave Wilson designs his
speakers to perform exactly the opposite of what you propose. He uses
diffraction pads to quell early reflections and the resulting comb filter
effects. He has a specific setup routine developed to optimally place
*his* speaker designs to maximize their presentation. The result is an
overall decent imaging ability, with a very sweet sweet spot. I listen
in the sweet spot, and don't care that the true sweet spot is quite small,
or that the image shifts as I walk around - that is irrelevant in my
usage. In the sweet spot, the sound is - to me - quite realistic, on a
good recording.
AE on the other hand uses ML panels. While these can sound very good, and
certainly have a much wider listening angle than my Sophias, they don't
sound as realistic to me. AE feels the opposite way I'm sure, quite
possibly for opposite reasons.
It's a fallacy to think that there is a single solution to disparate
interpretations of realism. As long as you refuse to accept that your
preference of illusion is neither universal, nor normative, I doubt your
quest will have a happy ending.
Keith
So back to my paradigm of a physical reconstruction of the (or perhaps you
may force me to say "an") audio event, the whole Bose research study,
architectural acoustics knowledge, freeing the sound from the speakers, all
that.
To slightly rephrase the Bose research work, Dr. Bose found that hi fi
sucks, so they tried to figure out why. They went into the concert hall and
listened with a binaural head and measured the various sound fields, and
came back and examined the differences. Architectural acoustics designers
know full well what constitutes a good sounding hall, which is a wide, even
spread of the early reflected sound from the instruments and a full, rich,
but not echoey reverberant field. We were trying to reproduce that huge
sound field from two point sources in front of us, a difference that makes
the sound "harsh and strident" as they put it. Plus, the imaging would be as
Linkwitz and I would describe it, a series of cartoon flat images strung on
a clothesline between the speakers. Not saying that this is what you are
experiencing in your setup, just asking you to listen with a hard-nosed
critical attitude.
The macro situation that I find myself in is that audio people like yourself
keep pursuing the stereo idea that you want the pure, unadulterated recorded
sound to come to your ears unmolested by the listening room in a high direct
field, the acoustic duplicate of the electrical input idea. They will put
absorption at the points of the first reflections using mirrors to assist
them, and baffle up their speakers to try and keep all of the nasty
reflected sound away from the room, or anywhere except directly to your
ears - the exact opposite of what they should be doing. But no, no matter
how faithfully you believe such a theory, you just cannot take the huge,
wide set of fields that were recorded and pipe them all through just two
points in space and have it sound anywhere near the same in a mistaken
attempt at a false goal of "accuracy."
During our discussion I stumbled upon a most interesting ad in Playback, the
electronic version of the Absolute Sound/Perfect Vision people:
http://www.avguide.com/article/audie...ample+Articles)
I wrote to John McDonald with some questions about this interesting speaker.
I asked him if I could see their instruction manual on speaker placement
because this is where I came into this movie - when I wrote to Bose and told
them that their speaker placement nistructions were all wrong. I found that
the Audience people were doing the same thing with their manual and ads,
trying to tell people that you can place their speakers anywhere you want
and get great stereo.
And the beat goes on. Thanks again for a great discussion.
Gary Eickmeier