Gain Riding Logic - did it ever sound good?

[kfbkfb]

AFAIK, the Sansui QS preprocessing so that a QS variomatrix decoder could decode SQ [called phase matrix] was the 1st non-gain riding SQ logic decoder.

Did gain riding logic (not gain riding w/any sort of variable matrix assistance) ever sound good (i. e. the matrix decoded soundfield sounded close to discrete)?

(I only heard gain riding SQ decoding once - in an audio store - w/Sony SQD-2070, was not impressed)


Kirk Bayne

 

[par4ken]

AFAIK, the Sansui QS preprocessing so that a QS variomatrix decoder could decode SQ [called phase matrix] was the 1st non-gain riding SQ logic decoder.

Did gain riding logic (not gain riding w/any sort of variable matrix assistance) ever sound good (i. e. the matrix decoded soundfield sounded close to discrete)?

(I only heard gain riding SQ decoding once - in an audio store - w/Sony SQD-2070, was not impressed)


Kirk Bayne

I always thought that full logic sounded good. When I listen today though I really notice the fixed blend that was used across the rear. When I used to run my Heathkit decoder I added a "dimension control" to it so that I could increase the gain riding effect, I wanted to hear it working. When set up "properly" the pumping action is not really noticeable.

Lafayette for one made a very good full logic decoder! Michael Robin was so pleased with his that he sold me the S&IC that he had gotten his hands on instead of keeping it for himself!

I recently purchased another Heathkit SQ decoder that I want to experiment with. To start I'm going to reduce that rear blend.

A lot of the CBS (Columbia/Epic) SQ mixes were done especially for gain riding decoders. Argent "In Deep" comes to mind. Even the discrete version has sounds dominating front to rear alternately. The sound field seems to alternately pan from front to rear and back.

 

[Sonik Wiz]

I always thought that full logic sounded good. When I listen today though I really notice the fixed blend that was used across the rear. When I used to run my Heathkit decoder I added a "dimension control" to it so that I could increase the gain riding effect, I wanted to hear it working. When set up "properly" the pumping action is not really noticeable.

Lafayette for one made a very good full logic decoder! Michael Robin was so pleased with his that he sold me the S&IC that he had gotten his hands on instead of keeping it for himself!

I recently purchased another Heathkit SQ decoder that I want to experiment with. To start I'm going to reduce that rear blend.

A lot of the CBS (Columbia/Epic) SQ mixes were done especially for gain riding decoders. Argent "In Deep" comes to mind. Even the discrete version has sounds dominating front to rear alternately. The sound field seems to alternately pan from front to rear and back.

I never owned a Space & Image composer but I've had every flavor of SQ there was from simple decoder to Fosgate Tate II. Oh and today of course the SM v2.In the middle I had a Kenwood 9940 with Full Logic Wave matching & vari-blend. Demoed in the store with PF's Money (of course) it sounded great. And Santana & Blue Oyster Cult was a delight to my in-experienced ears. At home with the receiver the I could hear something not quite right on orchestral, some jazz, & even some Art Garfunkel. Turning the balance all the way to the rear I could hear lots of pumping & the vari-blend switching on & off. It should be masked by complimentary changes in the other chs but it never did that too well. Once you hear the artifacts they are always there.

Disclord originally lived in Albuquerque, NM. He had tile floors & stucco walls. He said the acoustics completely smoothed out the pumping and all he cared about at that point was high separation.

And I beleive @kfbkfb is right... the Sansui Phase Matrix decoder was the first non- gain riding decoder for SQ. It did not have as high ch seperation specs compared to full logic decoders, but it was smooth and much better than SQ decoders in ealy 70's with fixed blend.

 

[ar surround]

No.

 

[par4ken]

No.

That is quite a blanket statement! I suppose that you haven't heard every full logic decoder, then your comment would make sense.

In fairness I've made similar statements about Dolby I've never heard any Dolby decoder that sounded any good on music! I won't go so far as to say that none exist, just that I've never heard any!

 

[ar surround]

That is quite a blanket statement! I suppose that you haven't heard every full logic decoder, then your comment would make sense.

In fairness I've made similar statements about Dolby I've never heard any Dolby decoder that sounded any good on music! I won't go so far as to say that none exist, just that I've never heard any!

The question was:

Did gain riding logic (not gain riding w/any sort of variable matrix assistance) ever sound good (i. e. the matrix decoded soundfield sounded close to discrete)?

So my blunt "No" response does not apply to later units such as the Fosgate Tate II, which I have heard do it's thing and it does it exceptionally well. Also, I owned a Lafayette SQ W decoder with wave matching and vari-blend. It worked nicely if the mix was done properly for the SQ matrix. Now I have a Surround Master, which is a modern-day marvel.

 

[kfbkfb]

AFAIK, gain riding only logic was an integral part of the (Peter) Scheiber [IIRC, called Dimension 4] matrix system, the first AES paper about SQ by CBS mentions gain riding as the only method for channel separation enhancement.


Kirk Bayne

 

[par4ken]

The question was:

Did gain riding logic (not gain riding w/any sort of variable matrix assistance) ever sound good (i. e. the matrix decoded soundfield sounded close to discrete)?

So my blunt "No" response does not apply to later units such as the Fosgate Tate II, which I have heard do it's thing and it does it exceptionally well. Also, I owned a Lafayette SQ W decoder with wave matching and vari-blend. It worked nicely if the mix was done properly for the SQ matrix. Now I have a Surround Master, which is a modern-day marvel.

Thanks for the clarification. Technically vari-blend is not variable matrix as the blending comes after the decode (is not a part of the original decode process). Sorry if I'm splitting hairs.

 

[Doug G.]

par4ken, is the Heathkit decoder you are talking about the three MC chip one? That is the one installed in the Bell & Howell quad amplifier I bought (otherwise the same as the Heathkit AA-2010 amplifier which just has the universal decoder). Unfortunately, when I switch it in, the sound is very distorted. I haven't really troubleshot it yet as I don't use it in my system but maybe someday.

Doug

 

[par4ken]

par4ken, is the Heathkit decoder you are talking about the three MC chip one? That is the one installed in the Bell & Howell quad amplifier I bought (otherwise the same as the Heathkit AA-2010 amplifier which just has the universal decoder). Unfortunately, when I switch it in, the sound is very distorted. I haven't really troubleshot it yet as I don't use it in my system but maybe someday.

Doug

Yes it is. I always liked those Motorola Chipped decoders. The Sony chipped ones are a pain to adjust properly and don't sound as good to me.

I didn't need another decoder but the Heathkit is a bit of a nostalgia trip for me. I had forgotten that they use fixed blend as well as vari-blend across the rear. I guess that without the fixed blend the vari-blend action would be too noticeable. CBS did change the resistor from 4.7K to 6.8K to increase the separation from 12 to 15 dB . I'm thinking that it would be cool to try to reduce it further or make it switchable or adjustable!

 

[jaybird100]

The Sony SQD-1000 decoder, which was the first SQ decoder I bought, used gain riding to try to enhance separation, but the "pumping" effect was highly annoying. Sony referred to the method as "partial logic". It was a valiant first attempt, but when you see how far any matrix decoding has progressed (the Surround Master comes to mind), well, it makes me wonder what would have been had decoding at that level been available back in the early 70's.

 

[Doug G.]

Wives still would have been, "Oh no you don't" to guys trying to put a full blown quad system in their living rooms.



Doug

 

[MidiMagic]

As an employee of an audio store, I often took home various decoders and recordings to try out and report on.

I was using an SQ record with mostly ambiance in the rear channels and was irked by the gain riding in the SQ decoder (I think it was Sony SQD-1000, but that was 50 years ago). The rear ambiance kept changing level as the gain riding acted.

 

[par4ken]

The Sony SQD-1000 decoder, which was the first SQ decoder I bought, used gain riding to try to enhance separation, but the "pumping" effect was highly annoying. Sony referred to the method as "partial logic". It was a valiant first attempt, but when you see how far any matrix decoding has progressed (the Surround Master comes to mind), well, it makes me wonder what would have been had decoding at that level been available back in the early 70's.

I picked up one of those (SQD-1000) cheap on eBay years ago. I don't believe that it includes any form of logic. It's just a basic decoder. I just pulled it out of the shed so will check it out. The box is rather nice. With the guts removed it would nicely fit an Involve SQ evaluation module!

The early front to back logic decoders were often derided by the audio press and were quickly supplanted by the full logic decoders. The Lafayette SQ-L (F-B Logic) decoder does sound rather nice though.

I checked HiF Engine and there is no SQD-1000 manual there. I did find mention of it on Tab Patterson's site.

http://www.4channelsound.com/logic.htm

 

[Doug G.]

Yes, the SQD-1000 is just a basic (3dB separation except for front L-R which was like regular stereo - SQ doesn't compromise the 20dB separation there) decoder. It was Sony's first decoder.

Doug

 

[kfbkfb]

AFAIK, the Sony SQD-1000 has front-back gain riding only logic, an early Sony SQ ad stressed that SQ maintains full channel separation LF/RF and LB/RB, so gain riding was their only option since they didn't want to reduce LF/RF and LB/RB channel separation at all.

(if I can find the ad, I'll scan it and post it)
edit: found it, posted pdf in the Quad in the Media section


Kirk Bayne

 

[jaybird100]

Wives still would have been, "Oh no you don't" to guys trying to put a full blown quad system in their living rooms.



Doug

Have you noticed that, all of a sudden, it's HER living room, not OUR living room? She has assumed full ownership of whatever room hubby wants to express himself.

 

[jaybird100]

Yes, the SQD-1000 is just a basic (3dB separation) decoder. It was Sony's first decoder.

Doug

The gain riding was more annoying than anything else. But, as you say, it was a first attempt.

 

[par4ken]

AFAIK, the Sony SQD-1000 has front-back gain riding only logic, an early Sony SQ ad stressed that SQ maintains full channel separation LF/RF and LB/RB, so gain riding was their only option since they didn't want to reduce LF/RF and LB/RB channel separation at all.

(if I can find the ad, I'll scan it and post it)


Kirk Bayne

That would be incorrect, no logic at all in that SQD-1000. Correct that It would've maintained full left to right separation (no blend). That was always the strength of SQ! You guys must be thinking of a different model, with front to back logic.

 

[Doug G.]

Dealer - "Are you sure 3dB will be enough for customers to be wowed by quad?"

Company Rep. - "Oh heck yeah, It's easy to hear where things are with 3dB."

The Public - Shrug.