On Mon, 26 May 2008 02:57:54 GMT, Martin Leese
wrote:

Serge Auckland wrote:

"David Looser" wrote in message
...
...
The BBC's Matrix H was yet another matrix system, but one that came out
of Michael Gerzon et. al's work on ambisonics, and which was evaluated
for broadcast. The BBC did some test transmissions in Matrix H, but it
never went into full service as it didn't have full mono compatibility
(something the BBC was somewhat paranoid about at the time) and anyway,
the whole quad thing had pretty much gone away by then.

The history of Matrix H and its relation to
Ambisonics is nicely described on Wikipedia
at:
http://en.wikipedia.org/wiki/Quadrophonic

The BBC produced Matrix H. This was
combined with Ambisonic 45J to give Matrix
HJ. This was then combined with UD-4/UMX to
give Ambisonic UHJ.

There was also the RCA "FM4" system, which seems to be the one you are
thinking of. This used a frequency-modulated carrier around 20kHz to
carry the band-limited rear channels.

You're thinking of CD4, which was the system used by RCA, JVC, Denon and
others. It was developed by JVC.

The rear channels of CD-4 were
full-bandwidth, not band-limited, so David
may have been thinking of UD-4.

It's a great pity that Ambisonics never caught on,

It is still around, and is currently
stronger than it has been for many years.
Visit www.ambisonia.com for over 100 pieces
available for free download. These are in
Ambisonic B-Format, and most are full-sphere.
You will need a software player to decode
the files. There are several available, all
free.

Also, visit my website (see Sig) for the
Ambisonic Surround Sound FAQ.

The original poster was interested in
obtaining a quad version of DSotM. If they
have a DVD burner then to find something
which might interest them, they should
Google for "dsotm torrent quad".

Does anyone remember the BBC's late night experiments in 4 channel
sound in the early 70's? They used 2 stereo FM channels.

Or for that matter their late 50's stereo tests on a Saturday morning
using BBC TV sound and BBC Third Programme as the two channels. I
remember my dad moving the (very large) radiogram into the correct
position......and my mother's horror!

John J Armstrong