[William Sommerwerck]

"Scott Dorsey" wrote in message
...
William Sommerwerck wrote:

No. There weren't any. But all quadraphonic matrixing systems -- SQ,
QS, EV, etc -- require logic steering for good subjective separation,
even though they don't have center channels.

Actually, I have never seen an SQ or QS matrix system with steering.
The ones I saw all required pretty precise level setting to get good
separation and they all drifted a bit.

I've owned four SQ decoders. The Sony decoders used gain riding (rather than
cancellation), and produced extremely crude effects. The Audionics Space &
Image Composer was the first that worked without drawing too much attention
to itself. The Fosgate Tate II decoder (which I still have) had such rapid
logic action that you could turn sideways and the image remained stable.

I had two QS decoders, the Sansui QSD-1, then the QS-D1000. The first was a
multi-band unit, the latter single-band. QS wasn't very good for classical
music, because it required lateral separation enhancement (which SQ
doesn't). You could hear the orchestra image slightly widening and
narrowing. (I no longer have these, because I didn't have a lot of QS
recordings, and I needed money. They each sold for a large sum.)

The Fosgate is a-workin' still (classic MAD ad spoof), and is stable. The
only user adjustment is an input-balance control, and it's required the same
setting as long as I've owned my current pickup.


The first generation of Dolby Stereo had no steering, and really none of
the theatrical Dolby Stereo decoders have ever had analogue steering.

As far as I know, that isn't true. The earliest generation used a modified
QSD-1.

Steering isn't quite the right term. Fantasound used steering. Dolby Stereo
(and SQ and QS) used dynamic cancellation.


They just assumed everyone would do the A-chain alignment properly
enough that the separation would be good. Sometimes they did,
sometimes they didn't.

That's a different issue, of course.