In article , David Looser
wrote:
"Fleetie" wrote in message
...


With the RCA system in theory crosstalk should be very good (at least no
worse than normal disc stereo), but as you realised there were serious
problems with the sub-carrier at the top of the audio band. I had no
practical experience of this system, but I do remember that it didn't do
well commercially. If a record of this type is anything other than
pristine I would guess that the sub-carrier would be seriously reduced
in amplitude from it's new condition.

I can also recall at least one JAES paper discussing how to cope with the
large levels of intermod distortion between the audible and ultrasonic that
risked making the results such that decoding would fail, or be dreadful to
endure!

With the SQ and QS I imagine that someone could now write a computer
program that did the channel seperation in software, and you could then
playback or make a '4-channel' output. But I have no idea how many working
SQ/QS/H/etc decoders still exist in working order. IIRC one of the CD
lables (Unicorn?) did also produce matrix encoded CDs... May have one or
two somewhere...

Slainte,

Jim

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