Another (possible, early 1970s) Discrete Quad Disc System

[kfbkfb]

40 years ago today (22nd), RCA introduced their CED Videodisc system, in 1972, RCA planned to include (FM carrier based) discrete quad audio on their videodisc:

From the book:
RCA and the VideoDisc:
the business of research

Page 152: (status report in November 1972)

"Goal of four stereo channels: one achieved"


Strange wording, but since this initial report, I haven't read anything about how RCA planned to implement this (maybe with a CX type NR system on all 4 channels since the sound quality of the CED soundtrack wasn't HiFi with regard to noise).


Kirk Bayne

 

[furui_suterioo]

Doesn't VHS hifi use FM carrier based stereo, seems like that could have been made to accommodate discrete quad.

 

[Soundfield]

From the book:
RCA and the VideoDisc:
the business of research
book:
Page 152: (status report in November 1972)
"Goal of four stereo channels: one achieved"
Strange wording...

Misprint for none achieved I'd have thought!

 

[atrocity]

Doesn't VHS hifi use FM carrier based stereo, seems like that could have been made to accommodate discrete quad.

I think Beta HiFi, VHS HiFi, analog Laserdisc and CED all used FM audio. I remember going to Laserdisc after RCA announced the death of CED and assuming I'd no longer have to put up with noise pumping. Boy, was I wrong!

 

[kfbkfb]

LaserDisc (NTSC and PAL), Betamax (PAL only) and VHS (NTSC and PAL) could have added more FM carriers to provide discrete Quad audio, Betamax (NTSC) didn't have any more bandwidth to add carriers.

IIRC, in the late 1980s/early 1990s, Panasonic showed a prototype S-VHS VCR that recorded VHS HiFi + PCM (stereo) audio + VHS picture, all on the same tape at the same time.

Years ago, in another forum, I mentioned to Roger Dressler (then of Dolby Labs) that I thought this technology could be adapted and used to add 5.1 Dolby Digital audio to regular VHS, AFAIK, Dolby Labs didn't follow up on this.

If Quad had become the norm by the time the RCA CED videodisc had been introduced, I don't know if discrete Quad audio would have would have helped in sales.


Kirk Bayne

 

[furui_suterioo]

VHD/AHD also had 4 channel pcm capability, probably was never used.

View attachment 55476

 

[kfbkfb]

Just remembered, in early Spring of 1984, RCA announced that they planned to add PCM digital audio (probably stereo) to the CED videodisc (specifically in the frequency range above the video carrier), since Laserdisc had added PCM digital audio too (of course, Laserdisc became the 1st format to offer DD 5.1 in 1995).


Kirk Bayne

 

[kfbkfb]

Misprint for none achieved I'd have thought!

RCA introduced Stereo on CEDs in 1982 (no mention that CED could now contain Dolby Surround content):


(I watched my Flash Gordon stereo CED earlier today, the audio "scratchiness" caused by dropouts didn't confuse my Dolby ProLogic decoder)


Kirk Bayne

 

[quadtrade]

Just remembered, in early Spring of 1984, RCA announced that they planned to add PCM digital audio (probably stereo) to the CED videodisc (specifically in the frequency range above the video carrier), since Laserdisc had added PCM digital audio too (of course, Laserdisc became the 1st format to offer DD 5.1 in 1995).


Kirk Bayne

And DTS! We were right in the war with the Millennium 2-4-6.

 

[kfbkfb]

In all the interviews and articles I've read (since 1972), I don't recall anyone asking MCA/Philips about possible Discrete Quad audio in the Discovision/VLP/Laserdisc videodisc system.


Kirk Bayne