Stereo-4?

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ArmyOfQuad

2K Club - QQ Super Nova
Since 2002/2003
Joined
Apr 22, 2002
Messages
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Location
Attleboro, MA
I have a thing for moog albums, so moog quad albums are something I buy up whenever I have the chance. I recently acquired a Big Band Moog quad LP. But it says it's for "Stereo-4". I'm guessing that's some kind of pre-SQ matrixing format? Anyone have more info on this? It seems to decode through my tate, but I'll have to do some comparing with my Q8 sometime when I get a chance.
 
From Mark Anderson's discography:
KEITH DROSTE -
Big Band Moog. Realistic 50-2022 (EV), 51-3206 (Q8)
{The title above was released only in quad, no stereo version known}

Nowhere on this cover does it mention EV, nor does the word quadraphonic appear on this cover. Although, from my research, at the time of EV it wasn't even agreed upon how to properly spell quadraphonic. From what I remember from digging through tons of microfilm of old stereo review type magazines, before SQ existed, every company had their own different form of "quadrophonic" (the most popular spelling found from pre-SQ in the magazines I read), and it was creating much confusion. Although, most of these formats existed as ways to create quad from stereo, that was the main goal of quad pre-SQ. There was much debate at the time on whether the rears should be the same level as the fronts, or quieter, with what we now call "purists" arguing the rears should be quiet. One of their arguments for this was pointing out that at demonstrations where all speakers were equal volume, people would face any direction, where if the rears were quiet, people were more likely to face front. Anyways, if you have free time, and a library with microfilm of stereo magazines from the 70s, going through those are loads of fun, they all talk about quad as if it's "the future", when we all know it, unfortunately, didn't quite catch on. Anyways, EV is one of the many formats mentioned in the pre-SQ days. First, I'm curious what source lists this album as being EV, the only things this album says about quad is on the front cover it says "compatible stereo encoded for STEREO-4", then on the back after the explanation about recording the album, where it says nothing about quad, is says "You'll start to appreciate the 4 channel subtleties." My tate seems to be doing the job on this. But I haven't done extensive A-B comparison with the Q8 yet, and I just might have to dig up an EV decoder just to try this thing out on it and see what happens. If anyone has more info as to if this record is indeed EV, and more info on the format, please reply. Thanks.
 
Larry Clifton probably has the scoop on this one!
 
A couple of years ago I had an Electro-Voice EVX-4 decoder. Yeah - I know not a big claim to fame but hey, this is my fifteen minutes so stop laughing!

The EVX-4 had "STEREO-4(tm)" rather stylishly screened on the front panel. From memory while it could synthesize a little bit of quad from most two channel recordings. It's total inability to decode SQ and/or QS properly made me give it away (literally). I do still have a total of one picture of it showing the STEREO-4 trademark.

At some stage RadioShack sold a badge-engineered version of the EVX-4. In RadioShack guise I think it's model number was ARS-4. It too has STEREO-4 printed on the front panel.

At some stage I "moved up" to the Electro-Voice EVX-44 decoder. It lost the STEREO-4 trademark. This model, according to Electro-Voice's literature at the time used different matrix decoding to make it capable of decoding ALL (no less) matrix formats correctly. Well they were lying. Decoding QS or SQ material through the EVX-44 results in a blur of surround leaving the listener wondering if there really is a sweet spot. What it does do well is synthesize quad from most of my two channel CDs. It is still an active part of my audio system.

All the above decoders turn up on eBay from time to time and usually go for between US$5 and UD$30 so pick one up to hear your moog LP in all its 3db separated glory.

Somewhere around October 2002 someone offered an Electro-Voice Model 7445 STEREO-4 Encoder on eBay. I still have pics of that too.

Despite a number of feeble attempts, I have never managed to find out exactly what the original STEREO-4 encoding scheme was or how the scheme was modified to make it more compatible with QS and SQ. If anybody has any facts, I'd love to hear them.

Listen - all around the room,
Igor
 
Well, I'm working on getting the facts. I'm hoping to figure out what version of EV/Stereo-4 this records was encoded in, and the formula for it, so that I can....well, I dunno, do something with that info. I've got someone from electrovoice that said he would look through some filing cabinets and see what info he can dig up for me, but that he wouldn't promise that he could find anything since the technology is so old and the company has moved a few times since then and he doesn't know what was archived and such. I'll let you all know if he digs up anything. Funny that I'm going to all this trouble over an LP encoded in a technology probably more lousy than SQ, when I hate SQ as it is. But my Q8 of it is just so dead in the sound quality. I can't seem to win with my quad hobby, I hate the sound quality of 8-tracks, and I hate the seperation of matrixed LPs. The only thing that leaves is CD-4. Too bad all the labels couldn't just agree on that as a standard.
 
Stereo-4 *is* the EV matrix, that's what the EV matrix was called. Their later 'Universal Decoder' never had any discs specifically encoded for it. Compatibility with SQ made it butcher everything else, including their own discs. Basically for SQ you get a front left, front right, and front center, and rear center, but every other position is surround-mono with no two speakers EVER in phase with each other. Ironically it may have sounded better than non-logic non-10/40 blend SQ that turned dead-center front or rear into surround mono. The more I look at the characteristics of the later matrixes, the more I wish the Tate or VarioMatrix people had made their decoder for Stereo-4 instead. It's the only one that doesn't have mismatched phase angles all over the place, a sound is either completely in-phase or directly out of phase, period. If out of phase, it will have acoustic separation beyond it's apparent math, but SQ and QS are not symmetrical from left to right. They look that way on paper, but it's not true. A left channel signal with +90 degrees leakage into an opposite channel is not the same as a right channel signal with -90 degrees leakage into an opposite channel. To be symmetrical from left to right they would BOTH have to be +90 (or -90), not one on the left and another on the right. I wonder if there are any engineers or mathematicians here that could re-write the decoding coefficients to make the phasing artefacts of SQ symmetrical from left-to-right.
 
I've got Len Feldman's book, and he really spells it out. I wish I could get my hands on an actual EV encoded disc and decoder to check out.
 
Sticker.jpg


Here's a flyer about Ovation's early EV Stereo-4 recordings.

http://www.mediamax.com/bonodogo/Hosted/Ovation/Ovation Records Flyer.pdf
 
I decided to dig deeper into my files to see if I had more info on the Electro-Voice Stereo-4 system.

The decoder, the EVX-4 that most of us have seen, listed for $59.95.

The Encoder, the E-V 7445 listed for $795.00. Has anyone here seen/touched one? IgorGordan, please post some pictures.

Did you know that Peter Scheiber worked with EV on their encoding standards?

And Dreadstar, it should be mentioned in Len Feldman's book. He was the consulting engineer on EV's Stereo-4 project! ! !

http://www.mediamax.com/bonodogo/Hosted/Ovation/Electro-Voice EVX-4.pdf
 
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Did you know that Peter Scheiber worked with EV on their encoding standards?

And Dreadstar, it should be mentioned in Len Feldman's book. He was the consulting engineer on EV's Stereo-4 project! ! !

According to Feldman, he was contacted by Fixler, who had come up with something independent of Scheiber. Fixler's was intended for Quad headphones, but proved to work great with speakers. The two of them worked together, adjusting the parameters in real-time, the encoder going straight into the decoder while they listened and tweaked it!

They sold it to EV, but the final parameters took into account things like mono-mixdown compatibility, after being fed into a computer for the final equations EV used. What kind of computer EV supposedly had access to in 1970 I do not know lol.

Also significant to me is that Scheiber's was concieved from the beginning to incorporate logic, while EV was intended to work correctly without the expense.

I don't know why, but retro-fitting an EV decoder with logic seems extremely cool to me. I guess you'd have to see the sound distribution illustrations in Feldman's book to appreciate just how evil SQ and QS really are. Note that Feldman does NOT present them that way himself. It was a decade before "stereo image expanders" used phase relationships to affect apparent separation, and neither CBS nor Sansui had any idea what a mathematical abomination their systems really were. You could use a stereo image expander to compensate for the reduced seperation in EV or Dynaco, but in SQ or QS it would just make everything a whole lot worse. The Tate is so great because it uses logic to kill crosstalk by injecting reverse phase signals into other channels, but with EV or Dynaco or any other amplitude matrix, a stereo image expander would do the exact same thing without logic, because there are no whacky assymetrical phase angles like with the other two.

So say a Left Front signal has a 20% bleedover into the Right Front. No problem, just have a fixed setting to inject that exact amount out of phase into that channel, no logic necessary.

I can't wait to try this :)
 
From what I remember of the era, the EV Stereo-4 system was supposed to be an active version of something resembling the Dynaquad passive system. There was good left-right separation up front, but rear separation was minimal. Center front to center-rear separation was only about 3 dB. Logic would have helped, but no decoder with logic was ever offered for this system. There was some subjective compatibility with Sansui's QS system, which led companies such as Ovation and Project 3 to adopt QS when it became more popular. I had one of the original EV decoders back in the earlier days of quad. It was actually better for synthesizing quad from stereo than it was for decoding actual matrixed material. EV later revised the decoder, calling it a universal model, that was supposed to be closer to SQ. The system crashed and burned as soon as no more records for it were being produced. As for any EV records you may have, decode them as QS. That's closer to the original encoding than SQ.
 
Well I think this thread answers a question I had about the Hollins and Starr record I have. According to the posted Ovation flyer it is an EV encoded recording with the regular record number (without the QD), even though there is no EV sticker attached to my copy. So I will continue decoding it in QS and enjoy! :phones

I guess this means Ovation was first putting out Quad records in 1970?
 
Well I think this thread answers a question I had about the Hollins and Starr record I have. According to the posted Ovation flyer it is an EV encoded recording with the regular record number (without the QD), even though there is no EV sticker attached to my copy. So I will continue decoding it in QS and enjoy! :phones

I guess this means Ovation was first putting out Quad records in 1970?

Ovation and Project 3 were first out of the starting gate with quad LP's. Both used the EV system to start, and switched to QS.
 
Well I think this thread answers a question I had about the Hollins and Starr record I have. According to the posted Ovation flyer it is an EV encoded recording with the regular record number (without the QD), even though there is no EV sticker attached to my copy. So I will continue decoding it in QS and enjoy! :phones


I think you've come away from this with the wrong impression. It is only the *proportional* relationship in the power distribution that is a close match when playing EV and QS on each other's decoders. Neither Feldman nor any engineer from the Quad era seemed to grasp that it is not a trivial thing for rear channels to be out of phase with both the front channels. You would literally do better with a passive 4-channel synthesizer to play EV records than using a QS with it's plus-and-minus 90 degree phase alterations all over the place. I suppose a logic decoder would extrapolate more separation but that's my point, the separation would be *extrapolated*, not *recreated* from what was actually intended in the original recording.
 
I was working for Radio Shack when EV came out, we didn't even call it quad for another year or so...just "four channel sound".
Anyway, Fisher built for Allied Radio Shack a nice EV-based receiver, model was ARS-747. Never seen another EV-only receiver since then, has anyone else?
We used an EV version of "Enoch Light and the Brass Menagerie" to demo the unit, and I discovered early on, as has been posted by others, it did as good a job of synthing quad as decoding quad! Nice receiver, though, typical Fisher of the 70's. I saw one on Ebay a month ago, but bid too late.
Oh well, just wanted it for memories of those first glorious days of Quad!
As pointed out, EV-4 has NO weird phase shifts, so building a decoder for it is quite cheap and easy, no fancy j-filters needed. I have a few EV recordings, and play them through a Hafler (sort of) hook-up in my car...not bad!
Thanks for letting me share memories of when it all started,
regards from all corners,
TB
 
I was working for Radio Shack when EV came out, we didn't even call it quad for another year or so...just "four channel sound".
Anyway, Fisher built for Allied Radio Shack a nice EV-based receiver, model was ARS-747. Never seen another EV-only receiver since then, has anyone else?
We used an EV version of "Enoch Light and the Brass Menagerie" to demo the unit, and I discovered early on, as has been posted by others, it did as good a job of synthing quad as decoding quad! Nice receiver, though, typical Fisher of the 70's. I saw one on Ebay a month ago, but bid too late.
Oh well, just wanted it for memories of those first glorious days of Quad!
As pointed out, EV-4 has NO weird phase shifts, so building a decoder for it is quite cheap and easy, no fancy j-filters needed. I have a few EV recordings, and play them through a Hafler (sort of) hook-up in my car...not bad!
Thanks for letting me share memories of when it all started,
regards from all corners,
TB
Welcome to the website tejanoboy. Thanks for sharing your story about the "Rat-shack", I enjoyed reading it!
 
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