We're talking about two different things here. The Tate DES Chips were designed for SQ decoding - although Dolby Labs used them for their early Dolby Professional Cinema decoders of QS and their own Dolby Matrix as well.
The Fosgate Model 4 was designed by Jim Fosgate and was a pre-Tate product that incorporates early versions of many of his advanced matrix decoding technologies. They included Tate based decoders as well as the even more advanced "servo" decoding now found in Dolby Pro Logic II decoders.
You can check earlier threads here on QQ such as
http://quadraphonicquad.com/forums/showthread.php?p=66880 where folks have debated how well the Model 4 decodes SQ discs and how close it comes to a Tate Chip based system.
Another resource is Bob Popham who was involved with designing the Fosgate and Tate decoders - and still does maintenance and repair on them.
His web site is at
http://www.rjpc.com/
The thread was just confusing as to who meant what in the back and forth - but I think you mean the Model-4 was a POST-Tate product. I had, at one time, a DSM-3606 and I've also heard the Model-4 as well as the pre-PL*II Six-Axis decoder in my system - I
HATED the DSM-3606 and after going around and around with Fosgate over its performance (they replaced it with a new one two different times) got a Shure HTS-5300! I had the 3606 for almost a year before I couldn't stand it any longer, but it was Fosgate's lowest priced decoder then ($300 I think) and I couldn't easily afford more at that time. I ended up getting the Shure in trade for the 3606 - the guy didn't like the Shure because Harry Pearson had said something bad about it! So, he traded it for the Fosgate!
I've always wanted an Aphex AVM-8000 - back in the day it was "the" decoder to own and I'd still like to have one just to hear what it sounded like and its steering.
R. Scott Varner loved the Fosgate DSM-3606 and he thought I was crazy when I said I hated its performance! I haven't talked to Scott in over a year but I think he used it to derive side-channels in his system. BTW, does anyone have his email address? I lost it in a HD crash.
Anyway, I don't believe any of the non-Tate DES Fosgates decoded SQ well - and by that I mean accurately decoding the Left Surround and Right Surround SQ channels without them appearing substantially in the front channels. As you are aware, Left Front, Center Front, Right Front and Center Surround are encoded the same way in both SQ and the Dolby MP matrix, so they all work fine in terms of those channels... But Lb and Rb arn't placed correctly at all in non-SQ decoders and that ruins it for me. I don't want something that sounds "nice", I want what was encoded on the record.
Bob Popham came to my house one time when I lived in Albuquerque - back in, 1998, I believe - he was on a "Quad Roadshow" across the country - I'm sure he visited many of your guys homes too. He turned me onto the CD of Annie being SQ encoded - and Jimi Hendrix stuff being so 'magically' decoded in synthesis modes - it sure makes any surround synthesizer sound good! And I got to hear, first hand on my system, that last Japanese-only QS Vario-Matrix decoder built in the early 80's - was it the QSD-4? Personally, even with that decoder, I think QS is too phasey sounding and has too many side-to-side logic artifacts. The QSD-1 was the best, IMO, in regards to lack of artifacts but even then, it still had them - just not as bad as the broad-band Vario-Matrix decoders.
BTW, does anyone reading this have the whitepaper on the Scheiber 360 Spatial Decoder that Peter Scheiber wrote when he introduced that decoder in the 70's? I've never found anyone with it and would really like to have a copy - I'd like to know how he approached SQ decoding. None of his patents until the mid-to-late 80's ever covered anything but plain-old gain-riding logic... no advanced matrix-multiplier type logic was patented by him, which I found odd.
And has anyone ever heard that decoder or auditioned it extensively? If so, how was it?
