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S

Smarty

Jan 1, 1970
0
I have been reading these posts about quad sound and it reminded me of
my grandfather, William B. Snow, who did some pioneering work on
stereo in large rooms, getting a patenet in 1938, and on binaural
sound. When I was a young child he would let me listen to binaural
recordings he made with the mannequin heads. I could hear him walking
around behind me through the headphones, though what I was really
hearing was a recording. As a young child I was amazed by the
resemblance to live sound. He had a lab at his house with
oscilloscopes and other sound equipment that was fascinating to me. He
would have been very happy with the advancements made with sound
processing since his death in '68.
Eric
I too have been very impressed with binaural sound, and for a time
actually carried a portable Sony DAT recorder with microphones designed
to be worn in my ears, thereby capturing the precise signal structure my
ears and brain had learned over time to make direction of arrival
decisions. I recorded a number of live performances as well as a lot of
ambient daily activities, and the playback was as faithful and authentic
with regard to the original as any "high fidelity" scheme I have
encountered in my entire life including that from some audio systems I
have owned which cost many tens of thousands of dollars.

Stax has released a wonderful collection of binaural recordings on CD,
many of which I own, and other occasional binaural recordings are out
there from other labels as well. These have been recorded with a
mannikin dummy head which diminishes the accuracy and richness of the 3
dimensional experience somewhat compared to custom miked content, but
they are still very engaging and very much an improvement over stereo.
Unlike normal stereo headphones which present an image essentially
inside the head, these recordings open up the 3D space profoundly, even
if your earphones are small buds inserted in the ear canals.

You can be very proud of your grandad. I have tried to show my
grandchildren some examples of what I have done in my engineering
career, and, for the time being, they remain unimpressed.....!
 
S

Smarty

Jan 1, 1970
0
That is absolutely incorrect.

In all four-channel matrix systems, there are four inputs and four
outputs. A logic-directed, phase-cancellation decoder is capable of
dynamically "separating" the front and back information.



Of course it can, as assuredly as it can simultaneously localize
left-front and right-front signals, without any artifacts in the rear
channels.

It can do this for //any two// isolated channels. The decoder cancels
out their crosstalk in the other two channels. This breaks no laws of
math or physics.

Absolutely wrong answer! It most assuredly does violate both
mathematical and physical constraints. You might want to take a look at
the Ambisonics website where they state:

Matrix quad tried to get the four
original channels into two and back again,
which is impossible. A sound panned
around the control room in a circle (black)
would be replayed as a flat ellipse by SQ"

The flat ellipse shown in the Ambisonics reference is a typical result
of using a matrix approach, and other matrix designs have other odd
shapes, the Sansui QS matrix resulting in a heart-shaped / cardioid
sound field. In any such example for any choice of matrix coefficients,
the same result occurs, namely, the original directionality is lost, and
the sound field changes its shape with frequency. In Sansui's design
(later adopted for theater use as well) the rear channels effectively
produce a single centered rear channel at the acute vertex of the
cardioid. The brain and ear don't get any right rear to left rear
directionality whatsoever. In the SQ matrix, there is very little front
to back discrimination, with the virtual sound sources placed almost
entirely to the left and right of the listener, imitating spatial depth
by widening the front and adding hints to the rear.

Both are entirely avoided using discrete analog techniques of the
1960s, as in ***4 DISCRETE CHANNELS***. The matrix methods are synthetic
in that they synthesize an approximation to the discrete wavefronts,
good enough to fool the majority of listeners, but by no means accurate
or complete.


http://www.ambisonic.net/pdf/ambidvd2001.pdf as well as the surrounding
articles and introduction page for the Ambisonics approach.
 
W

William Sommerwerck

Jan 1, 1970
0
"Smarty" wrote in message
We have the problem of two people who agree, arguing over the agreement.

I am now (and have been) exclusively talking from a technical, engineering
viewpoint, and as one who is very qualified in this area. The various
systems which do not provide separate and discrete independent channels for
each of the 4 original channels cannot, do not, and will not separate and
maintain independent information for each of the four channels unless each
has its own distinct, isolated, channel.

That's what I said. Please re-read what I posted.

I'll repeat it, though. In a matrixed quad system, a properly designed decoder
can completely isolate one or two channels, when they are the only active
channels. That is what I said, and I stand by it. (To put it mathematically --
you can solve for two unknowns -- but no more -- when you have two equations.)

These is easily demonstrated with a single channel on a test disk, or by
playing a conventional stereo recording through an advanced SQ decoder.
Nothing comes out of the rear speakers.

You might be convinced that some matrixed scheme of putting 4 audio channels
into a 2 channel stereo medium can somehow permit the originals to be
faithfully extracted, but I am here to tell you that you are entirely wrong.

They can, under the conditions previously stated.

The more advanced version of SQ used gated, voltage controlled amplifiers
not unlike the more recent Dolby ProLogic scheme to move out of phase
information selectively to the rear.

The advanced SQ and QS decoders do not use "gated" amplifiers, which had been
abandoned years earlier. I owned such a decoder (the Sony SQD-2020), and it
sounded terrible, because it shut off channels with important material.


I'm going to stop at this point and simply state -- in an objective and
non-personal matter -- that you aren't familiar with how matrix and decoding
work. I wish I had some material to offer, but a lot of my source material has
been lost or misplaced over the years. If you'd to discuss this over the
weekend, we can get together on the phone.
 
W

William Sommerwerck

Jan 1, 1970
0
In fact, an SQ system could not localize a left-rear-only signal nor
Of course it can, as assuredly as it can simultaneously localize
left-front and right-front signals, without any artifacts in the rear
channels.
It can do this for //any two// isolated channels. The decoder cancels
out their crosstalk in the other two channels. This breaks no laws of
math or physics.

Absolutely wrong answer! It most assuredly does violate both
mathematical and physical constraints. You might want to take a look at
the Ambisonics website where they state:

Matrix quad tried to get the four
original channels into two and back again,
which is impossible. A sound panned
around the control room in a circle (black)
would be replayed as a flat ellipse by SQ"

READ WHAT I SAID, rather than what you think I said.
 
S

Smarty

Jan 1, 1970
0
in message
We have the problem of two people who agree, arguing over the agreement.



That's what I said. Please re-read what I posted.

I'll repeat it, though. In a matrixed quad system, a properly designed
decoder can completely isolate one or two channels, when they are the
only active channels. That is what I said, and I stand by it. (To put
it mathematically -- you can solve for two unknowns -- but no more --
when you have two equations.)

These is easily demonstrated with a single channel on a test disk, or
by playing a conventional stereo recording through an advanced SQ
decoder. Nothing comes out of the rear speakers.



They can, under the conditions previously stated.



The advanced SQ and QS decoders do not use "gated" amplifiers, which
had been abandoned years earlier. I owned such a decoder (the Sony
SQD-2020), and it sounded terrible, because it shut off channels with
important material.


I'm going to stop at this point and simply state -- in an objective
and non-personal matter -- that you aren't familiar with how matrix
and decoding work. I wish I had some material to offer, but a lot of
my source material has been lost or misplaced over the years. If you'd
to discuss this over the weekend, we can get together on the phone.
I will begin with your last and most offensive comment first. I am not
at liberty to describe this in detail given certain non disclosure
agreements, but I will leave you with the opportunity to research Peter
Scheiber and the patent rights sold to Dolby for the design and
implementation of original matrixing audio technology ultimately sold to
Columbia to become SQ. I can only state a single comment, which is that
Mr. Scheiber, a musician, and non engineer, holds the original patent,
but relied on a certain graduate university student to develop and build
his design concept. I will leave it to your fertile and most ad hominem
imagination to figure out who that graduate student was. And I will
remind you of my original introduction to this topic earlier in this
very same thread by stating that I had first worked in Toronto on a
matrixing audio encoder design for theater use starting in the 1960s.

Since you have already amply demonstrated an exquisite knack for putting
two and two together and getting two, I will now briefly summarize your
conclusion that we are supposedly violently agreeing upon.

If you are now stating that a 4 channel matrixing encode and decode
system can merely handle two channels at a time, then you are now
beginning to demonstrate and acknowledge their fundamental inability to
extract and isolate 4 channels independently. If you are somehow trying
to assert that by only doing two channels at a time, they somehow
preserve these 2 channels correctly in the presence of any other energy
arising from the other two channels whatsoever, you are utterly wrong.

The point of this is that given a 4 channel input, the very best you can
ever hope for are 4 poor imitations of the original 4 discrete signals.
If you are somehow arguing that the method succeeds with simultaneous 4
channel input, you are incorrect. This type of solution is referred to
by engineers as synthetic, since it uses a synthesis method to form
approximations of actual things. Think "Moog synthesizer" if you cannot
grasp the meaning in a more expansive way.

I have merely stated that such systems as we have been discussing are
"synthetic" and the notion that they somehow isolate and extract is
technically wrong.
 
C

Cydrome Leader

Jan 1, 1970
0
William Sommerwerck said:
"Cydrome Leader" wrote in message


Point well-taken. Movies often miss the opportunity to create a truly
immersive experience.




I had a variety of sources and processors. At the top was discrete open-reel
tape, which produced the most-spectacular consumer sound, until multi-ch SACD
came along. (I still have the tapes and an Otari quad deck.) It is unfortunate
that Sony has refused to reissue its huge library of Columbia surround
recordings on SACD.

Was "surround" at the time a true 4 channel recording?
For quad phonograph records, there was the Audionics Space & Image Composer,
an advanced SQ decoder that could wrap stereo recordings around you, often to
great effect. I also had an Ambisonic decoder for Ambisonic recordings. It
could do things similar to the Audionics, without requiring logic circuitry,
and did a superb job of ambience extraction.

For stereo recordings, I had an audio/pulse Model One, the first consumer
digital ambience device. It didn't generate high echo density, but used
tastefully, it could greatly enhance the sense of space. (I later replaced it
with the improved audio/pulse 1000.)

Out of these devices, which did true decoding of extra channels out of a a
two channel recording?

How did the encoded recordings sound if you skipped the decoders? With old
tape decks and Dolby noise reduction, it didn't matter on playback.
My current system includes the JVC XP-A1000 and Yamaha DSP-3000 hall
synthesizers. These are modeled on real halls (such as the Concertgebouw). You
can pick an appropriate hall (concert, recital, cathedral, opera, stadium),
then tweak the settings (if you wish) to fine-tune the sound to match the
recording's ambience. These devices are so natural-sounding, you cannot hear
them working until you shut them off.

I have a 6.1 system (no center speaker) with Apogee speakers and Curl
amplification.

There is no excuse to listen in two channels. Stereo is technically and
aesthetically obsolete.

unless all your recordings are only available in plain stereo.

I actually had a really hard time locating a surround sound audio test
file to use with a WD Live video/audio playing device. My surround decoder
has the generate noise on each channel test for setting up speakers, but
that doesn't tell you if it really understands the signals coming out of
the modern media player.
 
C

Cydrome Leader

Jan 1, 1970
0
channel recordings, other than with one of those boxes?
"
By summing the left and right channels and sending them to OP AMPS on the inverting inputs, resuling in the attenuation of the L+R component of both channels. By careful mixing, an audio engineer could do alot with that. A system called SQ came out which standardized the process somewhat and only nulled the mid to high ranges, leavng the bass relatively intact for the rear speakers which were ususally identical to the front speakers, unlike today. Today, usually nothing under 100 Hz is sent to the rear. Those little satellite speakers couldn't reproduce it anyway.

The standardization was simply the time constant of the feedback network and the actual amount of L+R attenuation. It was sort of licensed, and you could buy recording supposedly in "SQ", which meant that they were mixed in a way to take advantage of the standards.

Ah- SQ.

I've always wondered what that was. I seem to think I've seen that on
laserdiscs, and just checked mine, but none have it, not that I'd be able
to play it back correctly anyways.
 
W

William Sommerwerck

Jan 1, 1970
0
"Cydrome Leader" wrote in message
Was "surround" at the time a true 4 channel recording?

I'm not sure what you mean by "true". Matrixed recordings were considered
four-channel recordings.

The first modern surround recordings came from AR/Vanguard. They were called
"surround stereo", I believe. After that, the term "quadraphonic" was adapted.
(And please don't complain about mixing Greek and Latin. "Dinosaur" is a
similar hybrid.)

Out of these devices, which did true decoding of extra channels
out of a two channel recording?

Strictly speaking, none of them, as two-channel recordings, by definition, do
not have extra channels to be decoded.

However, some of the devices -- such as the Space & Image Composer and the
Ambisonic decoders -- could manipulate 2-channel recordings to wrap the sound
around you, or extract ambience, or both at the same time.

How did the encoded recordings sound if you skipped the decoders? With
old tape decks and Dolby noise reduction, it didn't matter on playback.

Generally, they sounded pretty much like regular stereo. The rear channels
weren't lost or diminished in level -- they simply appeared in the front.
(With SQ recordings, LR and RR often appeared slightly "outside" the front
speakers.) Unfortunately, recordings with ambience in the rear channels tended
to sound overly reverberant in stereo. EMI was obliged to reduce the ambience
levels.

Unless all your recordings are only available in plain stereo.

Not at all. Your control unit probably has surround modes to enhance stereo
recordings. And hall synthesizers can be bought on eBay.

I actually had a really hard time locating a surround sound audio test
file to use with a WD Live video/audio playing device. My surround
decoder has a noise generator to identify the channels when setting
up speakers, but that doesn't tell you if it really understands the signals
coming out of the modern media player.

If the program source is "discrete", then there shouldn't be a problem. *

Matrixed material generally requires manual mode selection. Lossy-compressed
materials (such as the various Dolby Digital formats) are //supposed// to be
correctly recognized by your control unit. Regardless, if playback doesn't
seem correct, try forcing the controller to different modes (if it allows
this). I agree that a test disk would be useful.

* With one exception. Some Blu-ray players won't properly output channels 6
and 7 unless you change one of the player's default settings.
 
W

William Sommerwerck

Jan 1, 1970
0
"Cydrome Leader" wrote in message
I've always wondered what that was. I seem to think I've seen that on
laserdiscs, and just checked mine, but none have it, not that I'd be able
to play it back correctly anyways.

The explanation given was almost completely incorrect.
 
C

Cydrome Leader

Jan 1, 1970
0
William Sommerwerck said:
"Cydrome Leader" wrote in message

I'm not sure what you mean by "true". Matrixed recordings were considered
four-channel recordings.

The first modern surround recordings came from AR/Vanguard. They were called
"surround stereo", I believe. After that, the term "quadraphonic" was adapted.
(And please don't complain about mixing Greek and Latin. "Dinosaur" is a
similar hybrid.)



Strictly speaking, none of them, as two-channel recordings, by definition, do
not have extra channels to be decoded.

However, some of the devices -- such as the Space & Image Composer and the
Ambisonic decoders -- could manipulate 2-channel recordings to wrap the sound
around you, or extract ambience, or both at the same time.



Generally, they sounded pretty much like regular stereo. The rear channels
weren't lost or diminished in level -- they simply appeared in the front.
(With SQ recordings, LR and RR often appeared slightly "outside" the front
speakers.) Unfortunately, recordings with ambience in the rear channels tended
to sound overly reverberant in stereo. EMI was obliged to reduce the ambience
levels.




Not at all. Your control unit probably has surround modes to enhance stereo
recordings. And hall synthesizers can be bought on eBay.

This may sound weird, but I'm against meddling with recordings and using
weird made-up affect that have nothing to do with the original recording.
If it wasn't in the recording, I don't want to hear it. Not everything was
recorded in a cathedral either. If I can hear the strange defects in a
recording as it was made and mixed, that's plenty exciting for me.

Again, this all depends on the type of music as well. Wether or not
heavily produced studio recording from Yes sounds better in a "concert
hall" or "jazz club" setting is questionable.
If the program source is "discrete", then there shouldn't be a problem. *

Matrixed material generally requires manual mode selection. Lossy-compressed
materials (such as the various Dolby Digital formats) are //supposed// to be
correctly recognized by your control unit. Regardless, if playback doesn't
seem correct, try forcing the controller to different modes (if it allows
this). I agree that a test disk would be useful.

* With one exception. Some Blu-ray players won't properly output channels 6
and 7 unless you change one of the player's default settings.

I had to screw with all the settings for type of sourround signals and
how they were outputted (hdmi/toslink or both) and what format and
compatibility modes to output to the decoder. The decoder only has a few
vague settings. Eventually it all worked, but the bluray player needed
firmware updates.
 
C

Cydrome Leader

Jan 1, 1970
0
William Sommerwerck said:
"Cydrome Leader" wrote in message

The explanation given was almost completely incorrect.

The explanation for SQ was wrong?
 
W

William Sommerwerck

Jan 1, 1970
0
"Cydrome Leader" wrote in message
This may sound weird, but I'm against meddling with recordings and
using weird made-up affect that have nothing to do with the original
recording. If it wasn't in the recording, I don't want to hear it. Not
everything was recorded in a cathedral either. If I can hear the strange
defects in a recording as it was made and mixed, that's plenty exciting
for me.

That's not weird. Over the years I've learned that most "enhancements" do
nothing to truly improve the sound. Worse, the better the playback equipment,
the more the enhancements become audible as unmusical changes.

Of course, two-channel recording is fundamentally limited in its ability to
convey directionality and spatiality. This might not be important if you're
listening to multi-miked studio recordings, but it /is/ important when the
music was (or should have been) recorded in an appropriate acoustic space.

The Carver Sonic Hologram actually does work -- at least with simply-miked
recordings. (I've had little experience with other crosstalk cancellers, which
might or might not work.) An Ambisonic decoder can "extract" the ambience from
a well-made recording and present it in a very natural-sounding manner.

Of course, such devices require sending the program through a processor, which
to an audiophile is generally a no-no. That's the beauty of a hall
synthesizer -- the generated ambience is played through four additional
speakers, and the original recording is left untouched.

Again, this all depends on the type of music as well. Wether or not
heavily produced studio recording from Yes sounds better in a
"concert hall" or "jazz club" setting is questionable.

I had to screw with all the settings for type of sourround signals and
how they were outputted (HDMI/TOSlink or both) and what format and
compatibility modes to output to the decoder. The decoder only has
a few vague settings. Eventually it all worked, but the Blu-ray player
needed firmware updates.

That's not surprising. Consumer photographic and electronics products have
become incredibly complex, and the idiots (I use the word deliberately,
because they are idiots) who write the user manuals neither understand the
products nor how to explain their use to the reader. I have long considered
starting a class-action suit against the major manufacturers for their lousy
manuals.
 
W

William Sommerwerck

Jan 1, 1970
0
"Cydrome Leader" wrote in message
William Sommerwerck said:
"Cydrome Leader" wrote in message news:[email protected]...
The explanation for SQ was wrong?

Yes. Smarty's explanation is based on a misunderstanding of the Scheiber
patents (which I looked at last night). And while we're at it, neither SQ nor
QS is derived from nor dependent on the Scheiber patents.
 
W

William Sommerwerck

Jan 1, 1970
0
"Smarty" wrote in message
"Cydrome Leader" wrote in message
You Sir are either an obnoxious troll or a deliberate liar, or perhaps both.
You certainly lack technical grounds for your conclusions. And I am only
impressed with your ability in such matters to take 2 and 2 and come up with
2, not only in quad sound discussions but in others I have now begun to
witness in the area of CRT physics.

You have picked The Wrong Person to attack on knowledge of surround sound.

I have no idea who you are or what your credentials are, but you certainly
lack technical prowess in the specific areas I am familiar which we have
mutually discussed in this forum.

I am a degreed EE, and a member of Tau Beta Pi and Eta Kappa Nu. I used to
make live recordings (stereo, quad, and Ambisonic), and have rubbed noses with
a few (not many) movers and shakers in the audio industry. At one time I was
the only audiophile reviewer who took surround sound seriously.

Peter Scheiber was indeed at the genesis of SQ, as much to provoke
a patent dispute with CBS as anything else.

I don't remember a patent dispute, but I've no doubt there was one. The
problem is that the Scheiber patent is for a fairly crude quad system, and
there is nothing //fundamentally// innovative about it that would allow it to
have, shall we say, a "controlling interest" in SQ or QS.

He was a musician who played lovely bassoon and his career had
essentially nothing to do with engineering, despite a great business
acumen and an ability to make claims which Ben Bauer and others
including Ray Dolby ultimately acquiesced to, mostly to avoid protracted
legal costs and battles.

That's hardly surprising. Though Scheiber's patents are pretty much valid, the
American patent system has long been a mess, with people winning suits based
on completely invalid patents. (The patent for intermittent wipers is a
classic example.)

I used to get the JAES. (I'm still a member, though I haven't paid dues in
years. Saul Marantz and Jon Dahlquist supported my membership.) My favorite
part of the magazine was George Augspurger's trashing of "new" audio patents.

I attended and supported some of this activity personally, and
know the truth, regardless of your claimed understanding.

What is [the] truth?

I know of what I speak. And you are a contemptible person.

You mean you don't like being told you're... mistaken.

The link below is not entirely accurate but the referenced paragraph which I
repeat below is correct:
http://quadraphonicaudio.wordpress.com/2009/07/12/several-pages-of-quad-bob/
"Peter Scheiber “invented” SQ encoding... which he presented at the 1969
AES. Columbia bought his patent and rights and then Ben Bauer of Columbia
Labs “named” it “SQ” and took over the development of SQ quadraphonic
sound."

Quad Bob is an acquaintance, whom I've not spoken with in several years.

If Peter Scheiber invented the SQ encoding system that Ben Bauer so vigorously
promoted -- that's news to me. His patent

https://www.google.com/patents/US3632886?printsec=abstract#v=onepage&q&f=false

misses an important element of SQ, QS, and Ambisonic UHJ encoding --
quadrature phase shift. If I recall correctly, this shift reduces or removes
ambiguity between front and back signals.

I checked the "Quadraphony" collection from the AES, published in 1975. It is
not comprehensive, of course, but it contains nothing from Peter Scheiber that
even remotely suggests SQ. If such exists, please provide a reference or send
a copy.
 
S

Smarty

Jan 1, 1970
0
If Peter Scheiber invented the SQ encoding system that Ben Bauer so
vigorously promoted -- that's news to me. His patent

https://www.google.com/patents/US3632886?printsec=abstract#v=onepage&q&f=false


misses an important element of SQ, QS, and Ambisonic UHJ encoding --
quadrature phase shift. If I recall correctly, this shift reduces or
removes ambiguity between front and back signals.

My incredulous reaction:

Is it even slightly possible that William, claiming to be a graduate
E.E., (member of Tau Beta Pi* and Eta Kappa Mu honor societies no less),
is capable of actually believing that:

1. trying to encode 4 separate audio channels into a 2 channel standard
vinyl LP system and adding 90 degree quadrature phase shifts could
possibly "remove the ambiguity between the front and back signals" ??

2. "Whether purity is good or bad, the electron beams have to land
/somewhere/. In a B&W image, it might not matter much if red winds up on
blue, blue on green, and green on red. The result will be /something/
approximating a shade of gray. "

These are not the logical or technically insightful comments of a
degreed E.E. regardless of claimed honor society memberships.

These are the statements of someone who does not understand how either
audio channels or CRTs work.

Might I ask you to explain, for example, how putting a 90 degree phase
shift onto any of this audio would remove the ambiguity of front versus
back? And yes, I am aware that some but not all of the competing matrix
schemes using +/- 90 degree phase shifters in the rear made such
specious claims.

You may know how to read and quote others, but I would LOVE to hear you
explain technically how either of your hair-brained interpretations
ACTUALLY WORK from an engineering perspective. Any legitimate engineer
who knows these topics correctly could NEVER BUY INTO THIS BULLSHIT.

*I was a member of Tau Beta Pi and shudder to think that other members
of this prestigious society could be so entirely clueless. I also am
surprised you are not or were not a member of the I.E.E.E. I was a
Senior Member for many years and began as a student member over 50 years
ago. Like the AMA for physicians and the ABA for attorneys, it is the
defacto professional organization for those who are real graduate E.E.s,
with over 400,000 members currently.
 
S

Smarty

Jan 1, 1970
0
I don't remember a patent dispute, but I've no doubt there was one.
The problem is that the Scheiber patent is for a fairly crude quad
system, and there is nothing //fundamentally// innovative about it
that would allow it to have, shall we say, a "controlling interest" in
SQ or QS.


That's hardly surprising. Though Scheiber's patents are pretty much
valid, the American patent system has long been a mess, with people
winning suits based on completely invalid patents. (The patent for
intermittent wipers is a classic example.)

If Peter Scheiber invented the SQ encoding system that Ben Bauer so
vigorously promoted -- that's news to me. His patent

https://www.google.com/patents/US3632886?printsec=abstract#v=onepage&q&f=false


misses an important element of SQ, QS, and Ambisonic UHJ encoding --
quadrature phase shift. If I recall correctly, this shift reduces or
removes ambiguity between front and back signals.
William, recall from modulation and estimation theory and Fourier
analysis that quadrature modulation //DEMANDS A CLOCK//, or must have an
ability to self clock. Neither of these exist in a compatible 2 channel
analog system of this type, and adding such a clock eliminates
compatibility with the entire world of analog playback systems. I will
assume you were not ascribing the design to this approach.

And of course the simple act of putting a 90 degree phase shifter into
the rear audio paths does NOT make their resulting signal quadrature
modulated. It bears no resemblance to the more widely understood I and Q
quadrature method used in many places including color TV to truly carry
independent data. It merely corresponds to a quarter of a wavelength
shift to the one and only amplitude conveyed by a singular waveform.
Even with careful microphone choices and placements along with a mixing
and recording chain which preserves phase integrity, the very best
outcome one can hope for is a third derived phantom source centered in
the rear, as was well demonstrated earlier by Hafler as well as some of
the 1960s Delco radio designs which ran L-R across the rear speakers in
a few cars. Given the signalling and compatibility requirements,
creating a rear center signal only was / is unachievable without also
forming front artifacts of a substantial nature.

As regards Scheiber:

Scheiber's original patent was in the 1960s. CBS did not file until the
early 70s, and their lawyers were appropriately committed to avoid
infringement issues, something that Peter very well understood and
capitalized upon. His approach was important only in that it came first.

Scheiber's method for producing 'surround sound' was neither superior
nor especially innovative, since all such techniques relied on an
incomplete / impossible technical foundation which could never deliver 4
separate channels at a time, nor could they 'isolate' nor 'extract'
information exclusively to a given channel while other channels were
present except in special cases. These special cases they naturally
demonstrated and portrayed as successful solutions. Putting designs
together which "worked" was not the problem; rather, the choice of
design parameters boiled down to those which appeared to interfere
least, and whose effects were dramatic without being exaggerated, a
compromise which is actually hard to achieve given the limit of 2
channels to work with. He and all the other contenders metaphorically
offered their recipes to put multiple ingredients into a stirred pot,
and then showed how they could, for some of the ingredients, some of the
time, recover individual ingredients.

Since the patent office and the courts award great benefits to 'prior
art', and since the matrixing approaches all were merely artistic
concoctions of time delays, phase shifts, gain controls, and their
associated time constant choices, the fact that one system might
actually sound better under some conditions but worse under others was
not a legal battle but a marketing battle. The legal battle was to
essentially avoid and if possible totally prevent infringement lawsuits,
which was both Columbia's and Dolby's primary objective. He wound up
with the credit for the "discovery" and was financially rewarded, but
never for selling a single encoder or decoder. His genius was really in
getting to the patent office first with a working prototype to
demonstrate proof of concept. For me it was an exciting time and the
first glimpse for me of the business side of electronics.
 
W

William Sommerwerck

Jan 1, 1970
0
To "Smarty"...

I could go on for several pages, but will limit myself. I //could// sum up
this entire exchange by saying that I feel like Gus arguing with Woodrow, but
other things need saying.

Several months ago I called David Janszen (the son of the late/great Arthur
Janszen) to ask about the modeling of planar radiators. He told me that the
analysis was rather more complex than I'd imagined, and referred me to Olsen.

Did I criticize him? Did I tell he didn't know what he was talking about? No.
I got a copy of Olsen, and though I haven't had time to study the appropriate
sections, I will eventually get to it. (There's a lot of material on acoustics
I've never fully understood, so it's worth reading for that, alone.) Now...
Even if David Janszen weren't an authority in speaker design -- even if he'd
been someone I'd never even heard of -- I would have taken his response
seriously.

There's nothing wrong with assuming that "some guy you've never heard of"
might -- just might -- know something you don't know. If he doesn't, you'll
eventually find out.

There's a difference between knowing and understanding. It's not enough to
know the facts. Understanding requires the mental effort to "wrap your head
around" a concept and make it your own. I like to say that if you can't
explain something (in relatively simple terms), you don't really understand it
yourself.

Unfortunately, too many people believe what they're told -- even when it's
dead wrong -- then try to defend their beliefs against rational -- or just
common-sense -- attack. (I have engaged in some of the most appalling
arguments here and elsewhere over people's misconceptions about digital
processing. I've also learned a few things in the process.)

Here again are the two patents I referred to.

https://www.google.com/patents/US3632886 (click on Abstract)

https://www.google.com/patents/US39...a=X&ei=47isUYfwOeP-igKhnoHIDg&ved=0CFMQ6AEwBA

Please at least browse them. If you have questions, ask and I will try to
answer them (though I don't have detailed knowledge of every aspect of
matrixed surround).
 
W

William Sommerwerck

Jan 1, 1970
0
"Smarty" wrote in message On 6/3/2013 7:15 PM, William Sommerwerck wrote:

Because the following comments are so ad-hominem, they require a response.
Might I ask you to explain, for example, how putting a 90 degree phase shift
onto any of this audio would remove the ambiguity of front versus back? And
yes, I am aware that some but not all of the competing matrix schemes using
+/- 90 degree phase shifters in the rear made such specious claims.

Read the patents.

2. "Whether purity is good or bad, the electron beams have to land
/somewhere/. In a B&W image, it might not matter much if red winds
up on blue, blue on green, and green on red. The result will be
/something/ approximating a shade of gray."
These are not the logical or technically insightful comments of a degreed
E.E. regardless of claimed honor society memberships.
These are the statements of someone who does not understand
how either audio channels or CRTs work.

In fact, Arfa said the same thing. But you didn't attack him, because you
perceive him as an expert.

You may know how to read and quote others, but I would LOVE to hear you
explain technically how either of your hair-brained interpretations ACTUALLY
WORK from an engineering perspective. Any legitimate engineer who knows
these topics correctly could NEVER BUY INTO THIS BULLSHIT.

Hair-brained? You mean hare-brained.

You are criticizing something you don't understand, that you have rejected
without consideration.

I was a member of Tau Beta Pi and shudder to think that other members of
this prestigious society could be so entirely clueless.

No comment.

I also am surprised you are not or were not a member of the IEEE.

One merely buys one's way into the IEEE. It is not honorary.

You don't have to be a graduate EE to join. I entered as an undergraduate,
around 1967 (which is pushing 50 years), and remember a special issue on the
Fast Fourier Transform, which was then coming into common use.
 
S

Smarty

Jan 1, 1970
0
To "Smarty"...

There's a difference between knowing and understanding. It's not
enough to know the facts. Understanding requires the mental effort to
"wrap your head around" a concept and make it your own. I like to say
that if you can't explain something (in relatively simple terms), you
don't really understand it yourself.

Precisely! This was the reason I asked you to explain why / how you
could make the statement that a 90 degree phase shift added to the rear
discrete audio channels in any encoder which mixes down to 2 channels,
to use your exact words, "removes ambiguity between front and back
signals". Again, to borrow your exact words, "If you can't explain
something (in relatively simple terms), you don't really understand it
yourself".
Here again are the two patents I referred to.

https://www.google.com/patents/US3632886 (click on Abstract)

https://www.google.com/patents/US39...a=X&ei=47isUYfwOeP-igKhnoHIDg&ved=0CFMQ6AEwBA


Please at least browse them. If you have questions, ask and I will try
to answer them (though I don't have detailed knowledge of every aspect
of matrixed surround).

I am extremely familiar with Scheiber's work and resulting patent, which
I read in various stages of its submission, and have certainly more than
'browsed' Bauer's patent and several others when they were issued. I
thank you for the opportunity to ask you any questions, and will, once
again ask you the simple question:

Why did you make the statement that a 90 degree phase shift added to the
rear discrete audio channels in any encoder which mixes down to 2
channels, to use your exact words, "removes ambiguity between front and
back signals" ?

Forgive my skepticism and my continuing disrespectful tone. If we were
both automotive engineers, and you made a statement that the anti
gravity feature of your engine provided enhanced gas mileage, I would
initiate the same type of request for clarification. Those who
understand modulation theory and these specific types of surround sound
devices would never make such a statement, and I am merely asking you to
explain how such an outcome could occur.
 
S

Smarty

Jan 1, 1970
0
"
Because the following comments are so ad-hominem, they require a
response.


Read the patents.

When I was in graduate school and earning a bit of extra income as a
teaching assistant, I genuinely feared being asked questions in front of
a group of people by younger students and not knowing the answer. The
natural and safe way to deal with all such situations was to reply to
the inquisitive student:

"Read the textbook"
In fact, Arfa said the same thing. But you didn't attack him, because
you perceive him as an expert.

Hardly, I perceive him as a very knowledgeable repair technician with
vast experience who may or may not have the understanding of the
underlying physical details of how things work in this specific area. If
I were to ask him, or you, or others on this forum a question like:

"Why isn't a pure white raster the outcome of mis-registered set of
beams, given that it supposedly does not matter where the beams land?",
he may be as clueless as I am.
Hair-brained? You mean hare-brained.

Excellent comment!


One merely buys one's way into the IEEE. It is not honorary.

You don't have to be a graduate EE to join. I entered as an
undergraduate, around 1967 (which is pushing 50 years), and remember a
special issue on the Fast Fourier Transform, which was then coming
into common use.

Absolutely true, and as I mentioned in my prior reply, I too joined as a
student, quite a few years before you, and actually do remember the
'discovery' of the FFT in that same time period.
 
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