On 6/3/2013 7:15 PM, William Sommerwerck wrote:
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.)

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/US363...page&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.