"Les Hemmings" wrote:

Eric F. Richards wrote:
Bob Miller wrote:

On Sun, 15 Oct 2006 20:47:00 -0400, SR wrote:

I am interested in learning more about Quadraphonic stereos and
it's music.
I seem to recall quadraphonic LPs came and went in a year or two in
the Seventies. No one could figure out what to put in the rear
speakers. It didn't make sense to be sitting in the middle of a band,
sound-wise.



Mike Oldfield's "Boxed" was produced in quad.. It sounded fine on my
stereo but i was itching to try it out on a proper quad system! Did i miss
much?

Les

I don't know. I never had unrestricted access to a quad system. what
I did -- and this works only on some systems and may be downright
unsafe on others -- was to set up a Hafler Matrix. This is a passive
arrangement of the rear speakers to pull out L-R and R-L information
for back speakers, just wiring them to an existing stereo.

Being a passive system, there isn't a lot of control on what you can
do with it, but it will pull out the surround/quad information in the
right environment.

To wire a Hafler Matrix, you need a system with a common ground for
the left and right channels. Since this isn't a graphic interface,
I'll draw out the wiring on a couple lines:

Left + on stereo ---- Red on Left/Rear speaker
Black on Left/Rear speaker ---- Black on Right/Rear speaker
Red on Right/Rear speaker ---- Right + on stereo

The speakers face each other and should be several feet back from the
listener to introduce a little bit of delay. The arrangement takes
some fiddling to get right, but works on the cheap.

FWIW, the Wikipedia article on Quad elsewhere in this thread claims
that the Hafler Matrix works as well as any other quad/surround method
for pulling the surround info out. I find that *extremely* hard to
believe. But it is a cheap, workable solution.

Regards,


--
Eric F. Richards

"Nature abhors a vacuum tube." -- Myron Glass,
often attributed to J. R. Pierce, Bell Labs, c. 1940