J. Gordon Holt on Circle Surround

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Last week, Stereophile republished the final review by founder J. Gordon Holt, who left the magazine in 1998 because he was passionate about surround sound--and it wasn't. (Hmm. Sounds vaguely familiar....)

https://www.stereophile.com/content/rocktron-cs-525-circle-surround-decoder
Not seeing the entire issue I womder what the reason was for republishing that column?

I subscribed to Stereophile for many years & over all I thought I learned a lot. Holt's articles were always thought proving at the least & informative at the best. Eventually I dropped my subscription because I was more interested in reading about high end surround sound than stereo. So So. Many issues were discarded but selectively as I kept the ones that did have some good surround sound articles & reviews. My subscription certainly expired by the time his last column came out. So thank you very much for the link I found it fascinating. And certainly he mentions challenges that exist to day such as for the good people at Involve Audio.

As a bookend, the left one, I'd like to offer what I believe is Holt's first ever article on surround sound from Pop Electronics 11/70 pg 63:
Hafler vs Scheiber 4 channels on disc.
It was the 1st article I ever read about this topic & it sent me to my parents KLH stereo with a 3rd speaker hooked up in the differencing placed behind me. I played the stereo Switched on Bach & life a'int never been the same sense. I guess I owe my passion for surround sound to Mr Holt. What a long strange trip it's been.
 
As a bookend, the left one, I'd like to offer what I believe is Holt's first ever article on surround sound from Pop Electronics 11/70 pg 63:
Hafler vs Scheiber 4 channels on disc.
It was the 1st article I ever read about this topic & it sent me to my parents KLH stereo with a 3rd speaker hooked up in the differencing placed behind me. I played the stereo Switched on Bach & life a'int never been the same sense. I guess I owe my passion for surround sound to Mr Holt. What a long strange trip it's been.

That's fascinating--thanks for that! (This link will get you directly to the article, b/t/w.) If it hasn't been done already, we should start an index page somewhere with links to articles like this. Somebody could put together a very cool anthology...

Most of this quad history is still new to me, so I didn't know that David Hafler was one of the early figures in bringing quad to the masses. (I see now that there's lots on the web about his system, including a year-old thread here on QQ that I missed.) I only knew him as the father of Dynaco, though by the time I was old enough to take an interest in hi-fi, he'd left and founded his namesake company. I built one of his first pre-amps, to pair with a Carver cube amp that I'd saved two years' worth of summer-job wages for. A few years later my apartment was burgled and I lost both pieces. Then just last year, decades later and on the other side of the country, I found the same unit--probably constructed a little more professionally than mine had been!--in a junk electronics store. Paid forty bucks for it, got it working, and now it serves as my turntable pre-amp.
 
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Aaaaah! Popular Electronics (sniff)!

I had totally forgotten that J Gordon Holt wrote for PE which I started reading in 1959 (gulp). In the early seventies I tried hooking up a center channel using a resistor network and a power amp because hooking a center or even two speakers to the output of power amps offended my electronic sensibilities. (circa 1971 or 72 after taking the Heathkit "Electronics for Scientists" and "Digital Electronics for Scientists" courses at the university. ) The Physics Professor who taught it tried to convince me to become a physics major (because where electronics were concerned I was a motivated stoont). The only time a college professor ever blew in my ear. I was not impressed with the way the Hafler/Klipsch system sounded and thus ended up a stereo nut for the next 50 years.

An interesting thing to note in that issue of Pop Tronics is the article immediately preceeding is sort of a post mortem review of the "Sweet Sixteen" loudspeaker system which was the result of a construction article in the early sixites which I remember reading. I was baby sitting to earn money and took my issue of Pop Tronics along on a job. I would look from cover to cover although when the Sweet Sixteen article came out I was not interested particularly in audio. But the 1970 article above very carefully enumerates the advantages and disadvantages of the Sweet Sixteen which imho were later hijacked in the Bose 901s.
"Numbers Game" Sweet Sixteen Review Article"
Original 1961 Sweet Sixteen construction article
I always wanted to build a sweet sixteen and try it out but never did. Another thing to keep in mind is that in 1961 when the article appeared most people were still listening in mono. It wasn't so bad. (edit what I really mean by "always" is AFTER the Bose 901s came out)
 
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It's interesting that with my Dynaco "4 Dimensional Sound Demonstration Record", the back channel is encoded louder than the centre front due to the use of only one rear speaker. I don't think that many people liked having the surround speaker placed directly behind them so latter two surrounds became the norm.
I have a Rocktron CS decoder for my car and a spare stored away. I also have a Gemini SP-1, a rack mount unit intended for DJ use. It has only four outputs plus a sub output. Although the Gemini is constructed rather cheaply and uses the equivalent of 741 op-amps on the outputs, it does preform well. I would take Circle Surround decoding any day over any form of Dolby.
Get a Gemini for decent surround on a budget.
The Sweet Sixteen reminds me of what we were doing as kids in the days of Mono, connecting up as many speakers as we could for a much bigger sound, sometimes not in the same box nor even in phase. Match impedance? Didn't worry about it then, old tube based amps didn't seem to mind the extra load.
 
That's fascinating--thanks for that! (This link will get you directly to the article, b/t/w.) If it hasn't been done already, we should start an index page somewhere with links to articles like this. Somebody could put together a very cool anthology...

Most of this quad history is still new to me, so I didn't know that David Hafler was one of the early figures in bringing quad to the masses. (I see now that there's lots on the web about his system, including a year-old thread here on QQ that I missed.) I only knew him as the father of Dynaco, though by the time I was old enough to take an interest in hi-fi, he'd left and founded his namesake company. I built one of his first pre-amps, to pair with a Carver cube amp that I'd saved two years' worth of summer-job wages for. A few years later my apartment was burgled and I lost both pieces. Then just last year, decades later and on the other side of the country, I found the same unit--probably constructed a little more professionally than mine had been!--in a junk electronics store. Paid forty bucks for it, got it working, and now it serves as my turntable pre-amp.

Cool story about the Hafler pre-amp. There are a few pieces of audio gear that has come gone for me that I would like to stumble across again!

I've never paid much attention to Circle Surround technology. IIRC it was an outgrowth from Hughes Sound Retrieval System and later on bought by dts & realized in the digital domain in I don't know what products. So I took a look at Rocktron patents & found some good info. I liked seeing that it was a legit 5-2-5 system that did have true independent L/R surrounds. Most decoders of that generation were basically Dobly matrix decoders with a token music mode thrown in. That also tells me it would probably have quite good performance for stereo to surround.

Perhaps someone smarter than me can take a look at Patent 5,319,713 and fig 5. The text sez this is another embodiment of the decoding process but it sure looks like another version of encoding. If so it marks the only time I know of prior to Involve Smart Encode that uses variable mixing at the encode point.

I can't find much on the Circle Surround decoder on the forum except for Quadzilla's ancient post. If he runs across this thread it would be good to hear his 1st hand experience.

And even tho it is mainly about the CS encoder, you can still find some good info about on Disclord's archive site.

Edit: bad link fixed. Thanks Gene
 
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It's interesting that with my Dynaco "4 Dimensional Sound Demonstration Record", the back channel is encoded louder than the centre front due to the use of only one rear speaker. I don't think that many people liked having the surround speaker placed directly behind them so latter two surrounds became the norm.
I have a Rocktron CS decoder for my car and a spare stored away. I also have a Gemini SP-1, a rack mount unit intended for DJ use. It has only four outputs plus a sub output. Although the Gemini is constructed rather cheaply and uses the equivalent of 741 op-amps on the outputs, it does preform well. I would take Circle Surround decoding any day over any form of Dolby.
Get a Gemini for decent surround on a budget.
The Sweet Sixteen reminds me of what we were doing as kids in the days of Mono, connecting up as many speakers as we could for a much bigger sound, sometimes not in the same box nor even in phase. Match impedance? Didn't worry about it then, old tube based amps didn't seem to mind the extra load.
You must have posted this note at the same time I was composing my previous entry! I would like to hear your impression of the CS decoder. You must like it. For stereo to surround how would you say it compares to other methods?
 
Aaaaah! Popular Electronics (sniff)!

I had totally forgotten that J Gordon Holt wrote for PE which I started reading in 1959 (gulp). In the early seventies I tried hooking up a center channel using a resistor network and a power amp because hooking a center or even two speakers to the output of power amps offended my electronic sensibilities. (circa 1971 or 72 after taking the Heathkit "Electronics for Scientists" and "Digital Electronics for Scientists" courses at the university. ) The Physics Professor who taught it tried to convince me to become a physics major (because where electronics were concerned I was a motivated stoont). The only time a college professor ever blew in my ear. I was not impressed with the way the Hafler/Klipsch system sounded and thus ended up a stereo nut for the next 50 years.

An interesting thing to note in that issue of Pop Tronics is the article immediately preceeding is sort of a post mortem review of the "Sweet Sixteen" loudspeaker system which was the result of a construction article in the early sixites which I remeber reading. I was baby sitting to earn money and took my issue of Pop Tronics along on a job. I would look from cover to cover although when the Sweet Sixteen article came out I was not interested particularly in audio. But the 1970 article above very carefully enumerates the advantages and disadvantages of the Sweet Sixteen which imho were later hijacked in the Bose 901s.
"Numbers Game" Sweet Sixteen Review Article"
Original 1961 Sweet Sixteen construction article
I always wanted to build a sweet sixteen and try it out but never did. Another thing to keep in mind is that in 1961 when the article appeared most people were still listening in mono. It wasn't so bad. (edit what I really mean by "always" is AFTER the Bose 901s came out)

J Gordon Holt did better than most at finding that balance between the eternal tug of war between hardcore audio objectiveness & the equally convinced subjective based audiophiles (Tice digital clock, anyone?). I don't think he was an EE man but he had a perceptive mind that overcame that. I remember an article he wrote regarding the non-stop parade of audiophiles that would ask him his opinion on cables, speakers, speaker coupling/de-coupling to the floor, room acoustics, etc. They would say does this really effect the sound. His reply was:" yes, all of this can effect the sound. The only thing that matters is whether you can hear it or not."

Before I had a true 5.1 system I was still intriuged at the usefulness of a center front speaker. I hooked up my front L/R speaqkers as a differenceing pair, just like you might be using rear speakers for a Hafler set up. Then I took a smaller speaker and wired the + input to the connecting wire between the front speakers and then that went to ground. So you had a certain amount of front L/R separation with center fill. First attempt was the center speaker was too loud with little L/R width. An 8 ohm resister in parallel with the front speaker fixed that . It was a very natural stereo width with a nice center fill. No gaps or speakers high lighted, no logic artifacts. Eventually I gravitated to the more conventional approach as a discrete center front is better for movie dialog. And there's always a way to turn it off.

RE: Sweet 16. I know that was a popular DIY speaker project but to me it didn't seem like the right approach to put a bunch of cheap speakers into an enclosure & expect the best. As the article said it accomplishes some goals but as time marched on that was solved else wise & over all better speaker driver quality could be used.

Somewhere buried in boxes in my garage is a Speaker Builder mag with an article on Amar Bose. One of the accompaning picture shows him standing in a field next to what I can best describe as a geodesic dome. Each triangle held what looked like a 12" full range speaker. The whole thing was taller than him. Obviously this was much more than a sweet sixteen. Like crazy, daddy-o.
 
You must have posted this note at the same time I was composing my previous entry! I would like to hear your impression of the CS decoder. You must like it. For stereo to surround how would you say it compares to other methods?
My first impression was that it was quite Tate like for stereo to surround synthesis. QS (surround mode), would be better as the stereo field is evenly stretched around the room. The Gemini and Rockton units have a Surround Level or Rear Effect control that might alter the decoding a bit but mainly boosts the rear outputs. I've listened to Circle Surround decoders without that control and was almost as unimpressed as with Dolby decoding.
 
Last week, Stereophile republished the final review by founder J. Gordon Holt, who left the magazine in 1998 because he was passionate about surround sound--and it wasn't. (Hmm. Sounds vaguely familiar....)

https://www.stereophile.com/content/rocktron-cs-525-circle-surround-decoder
I read that quite some time ago, and like everything, I forgot it at some point. But anyway setting up my listening/Living room I went with sort of large bookshelf type speakers, because the room is sort of unusual and because of budget. My rears are even hanging from heavy swivel mounts and pointed at my sitting position as a sort of "dual purpose" move.
But that being said, I had in mind some of Holt's philosophy. But whether intended or lucky, it worked out OK for me. Glad too: those damned swivel mounts were about $100 apiece IIRC.
 
I can't find much on the Circle Surround decoder on the forum except for Quadzilla's ancient post. If he runs across this thread it would be good to hear his 1st hand experience.

Several of us had and maybe still have the Sherwood car system with CS/DTS decoder

s-l1600.jpg


It was 20 years ago today... (sounds familiar? guess why...) released in 1999.
I used the decoder as standalone in my office, feeding its digital input by a Naka 5-disc cd-rom changer and driving a quad amp/speaker setup; i was set both for dts cd and regular stereo cd and could mix it togheter... funny times.
Depending on the stereo source, it can be quite convincing. 70's production with a lot of phasey stuff sounded really wild.
 
I purchased a standalone Circle Surround decoder for a Quadie in Australia to beat the import tax and had the opportunity to demo it before sending it off. I found it was a great for up-mixing stereo and really enjoyed it. I had a Tate and and Ambisonic UHJ decoder with Super Stereo as a reference at the time.
Later I picked up a Kenwood receiver with Circle Surround 2 and noticed a great improvement to the early Circle Surround decoder. The receiver has many adjustmets such as center width you can tinker with.,
I used this setup for years and always used the CS Music mode. Much better than DPLII and Neo.
I still use these Circle Surround II receivers for up-mixing the back center, left and right and front wide speakers wired to the surround channel feeds while the Marantz provides the 5.1.4 amplification. One CS receiver provides the 2 wide's and the other does the three rear speakers.
Pictures and layout, and wiring diagram in a pdf are here
Mark's CSII System Enhancements
 
My sound card, Revolution 7.1, had circle surround. PC, turn on thump, was a problem back then with direct analog connection. Nothing revolutionary, but not bad either...
 
There seem to be a number of Circle Surround rack mount decoders , ones apparently aimed at DJs on fleabay at the moment. Starting at opening bids of $20.
Some new in box or claimed never used. Balanced ins and outs.

https://www.ebay.com/sch/i.html?_fr...TitleDesc=0&_osacat=293&_odkw=Circle+Surround
These are a great bargain, I'v posted about the GEMINI SP-1 before. While they did cut corners a bit to keep the cost down, (I guess that DJ,s don't have the same kind of money to spend on equipment as audiophiles do), but the unit does still preform well. I'ts Quad actually 4.1 so no option of a centre channel, but does have a LFE output. It has a level test oscillator built in, output level pots, enhance control, input level indicator, clipping leds. Output can be bypassed to stereo, 4 speaker stereo, or diagonal stereo. I was actually listening to mine last night, I like the enhance control set about the 2 o'clock position.
 
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