Disclord
900 Club - QQ All-Star
After years and years of looking, I finally found and bought a Proton SD-1000 surround decoder which is a 100% clone of the Aphex ESP-7000 surround decoder that Aphex released in 1987. Unlike any other matrix surround decoder, the Aphex/Proton has a logic-directed Center Back surround output and in addition to decoding Dolby Surround (it's not an officially licensed Dolby decoder - Aphex/Proton got their surround license directly from the inventor of surround matrixing himself, Peter Sheiber) it has a full stereo surround mode that, like the Fosgate Tate II 101A, wraps the soundstage around you into a 270 degree U-shaped soundfield.
When Proton licensed the Aphex design, they basically had Aphex just package the ESP-7000 decoder into a newer, better looking box and used more modern, higher quality parts. The channel separation numbers are the highest of any matrix decoder I've ever come across - Center Front to L/R front, 45-50db - Left/Right Front to either rear channel, 50-70db and CF to CB, 80-90db.
the unit lets you adjust the logic enhancement in 3 steps - full enhancement, moderate enhancement which equals about 25db of separation and the minimum which is 6-15db depending on direction. The lower logic levels are for those recordings - mainly classical - that have very complex phase relationships that the decoder can't accurately track, so by reducing the logic enhancement, you are reducing the tendency for the decoder to misbehave and pump or move static images when they shouldn't be.
the Aphex/Proton decoder is a true Matrix Multiplier Vector Cancellation design and uses no gain riding - it relies on the correct matrix coefficients in the matrix multiplier section to cancel sounds from the channels where they don't belong while, at the same time, keeping the total power output (volume level) from every channel exactly the same - the only other decoders that were true constant power decoders were the Fosgate Tate II, the Shure HTS-5300 (the first 2 Shure models were not as accurate as the 5300), and the Involve Surround Master. Not even the 3-band Sansui QSD-1 could maintain constant power - for some reason, all of Sansui's Vario-Matrix decoders increased the level of the 'wanted' channel by 5-6db; the BBC confirmed this in both their extensive tests of various matrix quad formats and during the development of Matrix-H when adapting a QSD-2. Dolby Pro-Logic is supposed to be a constant power decoder, but under certain conditions the surround channel can pump by up to 8db. And PL–II, in every decoder I've heard, seems to have real problems with constant power too.
the Aphex/Proton's logic circuitry is a RatioMetric design that uses peak detection instead of true RMS based logic - the peak detection combined with Aphex's own VCA's and true analog multiplier's lets the logic properly enhance the directionality over a 90+ db range.
the seller of the Proton had listed it on Craigslist several times before, with no takers - face it, only crazy collectors like me want old, outdated surround decoders - and while he was asking $160 for it, I took a chance and offered him $20 plus shipping and a new, still sealed copy of the original, never released, Queen ANATO DVD-Audio disc - he flipped for that offer and accepted!
when the Special Edition of The Abyss had its short theatrical rerelease, I was lucky and got to hear a 'shoot-out' between Dolby Pro-Logic in the CP-65 cinema processor, the Aphex ESP-7000, the Shure HTS -5300 and the Fosgate DSL-2. The Dolby CP-65 came in dead last and sounded so slow in its attack times that you could often hear sounds moving just slightly behind the visual action - the Fosgate, while being co-designed by Jim Fosgate, Peter Scheiber and the Tate inventor, Martin Willcocks, and supposedly having adaptable time constants that continuously varied from a fast attack time of 3ms to a slow of 25ms was also, surprisingly, slow sounding with a blurred soundstage and had a lot of dialog sibilance spill to the surround channel - it also had a front soundstage that wandered L to R based on CF content. The clear winner was the Shure HTS-5300 which sounded like a fully discrete 4-track magnetic film and not a matrix - and like the Involve Surround Master, the Shure's channel separation specs are not particularly impressive - from 15 -25db depending on direction, but the Shure engineers knew how to apply the attack/decay times, etc. to achieve such stunning results. The Aphex was just barely behind the Shure, due mostly to some minor sibilance splatter. The theater was a Dolby SR equipped theater and so did not have the capability of playing stereo surround, so we couldn't check that type of playback.
So, a consumer Dolby Stereo decoder, the HTS-5300 - a non Pro-Logic one I might add, since Shure used their own patented Acra-Vector logic system, and a completely non-Dolby licensed decoder, the Aphex, beat the 'official' CP-65 decoding system for Dolby MP encoded surround titles - and by such a wide margin that it sounded like we were comparing matrix to true discrete sound.
When end my Proton decoder gets here I will be interested in comparing it to the Surround Master - a broadband analog decoder designed in 1986 or so VS a modern 3band DSP based decoder. My gut feeling is that the Surround Master will wipe the floor with the Proton. But it doesn't really matter because, like the Shure, the Aphex/Proton was a decoder I wanted back then and had no ability to buy. So I'm getting to collect the stuff I used to want and pay virtually nothing for it. I will be interested to see how decoding music into 270 surround with the Proton and then encoding it into either QS or Involve and decoding that with the Surround Master will turn out.
maybe I should make a DTS DVD demo of all the different surround decoders I have decoding the same film clip. Would anyone be interested in hearing that?
Oh, and before I forget - get a Desper Spatializer (the consumer unit). I have one and just bought another for $30 on eBay Monday. I'll tell you about it and why I bought two in another post.
When Proton licensed the Aphex design, they basically had Aphex just package the ESP-7000 decoder into a newer, better looking box and used more modern, higher quality parts. The channel separation numbers are the highest of any matrix decoder I've ever come across - Center Front to L/R front, 45-50db - Left/Right Front to either rear channel, 50-70db and CF to CB, 80-90db.
the unit lets you adjust the logic enhancement in 3 steps - full enhancement, moderate enhancement which equals about 25db of separation and the minimum which is 6-15db depending on direction. The lower logic levels are for those recordings - mainly classical - that have very complex phase relationships that the decoder can't accurately track, so by reducing the logic enhancement, you are reducing the tendency for the decoder to misbehave and pump or move static images when they shouldn't be.
the Aphex/Proton decoder is a true Matrix Multiplier Vector Cancellation design and uses no gain riding - it relies on the correct matrix coefficients in the matrix multiplier section to cancel sounds from the channels where they don't belong while, at the same time, keeping the total power output (volume level) from every channel exactly the same - the only other decoders that were true constant power decoders were the Fosgate Tate II, the Shure HTS-5300 (the first 2 Shure models were not as accurate as the 5300), and the Involve Surround Master. Not even the 3-band Sansui QSD-1 could maintain constant power - for some reason, all of Sansui's Vario-Matrix decoders increased the level of the 'wanted' channel by 5-6db; the BBC confirmed this in both their extensive tests of various matrix quad formats and during the development of Matrix-H when adapting a QSD-2. Dolby Pro-Logic is supposed to be a constant power decoder, but under certain conditions the surround channel can pump by up to 8db. And PL–II, in every decoder I've heard, seems to have real problems with constant power too.
the Aphex/Proton's logic circuitry is a RatioMetric design that uses peak detection instead of true RMS based logic - the peak detection combined with Aphex's own VCA's and true analog multiplier's lets the logic properly enhance the directionality over a 90+ db range.
the seller of the Proton had listed it on Craigslist several times before, with no takers - face it, only crazy collectors like me want old, outdated surround decoders - and while he was asking $160 for it, I took a chance and offered him $20 plus shipping and a new, still sealed copy of the original, never released, Queen ANATO DVD-Audio disc - he flipped for that offer and accepted!
when the Special Edition of The Abyss had its short theatrical rerelease, I was lucky and got to hear a 'shoot-out' between Dolby Pro-Logic in the CP-65 cinema processor, the Aphex ESP-7000, the Shure HTS -5300 and the Fosgate DSL-2. The Dolby CP-65 came in dead last and sounded so slow in its attack times that you could often hear sounds moving just slightly behind the visual action - the Fosgate, while being co-designed by Jim Fosgate, Peter Scheiber and the Tate inventor, Martin Willcocks, and supposedly having adaptable time constants that continuously varied from a fast attack time of 3ms to a slow of 25ms was also, surprisingly, slow sounding with a blurred soundstage and had a lot of dialog sibilance spill to the surround channel - it also had a front soundstage that wandered L to R based on CF content. The clear winner was the Shure HTS-5300 which sounded like a fully discrete 4-track magnetic film and not a matrix - and like the Involve Surround Master, the Shure's channel separation specs are not particularly impressive - from 15 -25db depending on direction, but the Shure engineers knew how to apply the attack/decay times, etc. to achieve such stunning results. The Aphex was just barely behind the Shure, due mostly to some minor sibilance splatter. The theater was a Dolby SR equipped theater and so did not have the capability of playing stereo surround, so we couldn't check that type of playback.
So, a consumer Dolby Stereo decoder, the HTS-5300 - a non Pro-Logic one I might add, since Shure used their own patented Acra-Vector logic system, and a completely non-Dolby licensed decoder, the Aphex, beat the 'official' CP-65 decoding system for Dolby MP encoded surround titles - and by such a wide margin that it sounded like we were comparing matrix to true discrete sound.
When end my Proton decoder gets here I will be interested in comparing it to the Surround Master - a broadband analog decoder designed in 1986 or so VS a modern 3band DSP based decoder. My gut feeling is that the Surround Master will wipe the floor with the Proton. But it doesn't really matter because, like the Shure, the Aphex/Proton was a decoder I wanted back then and had no ability to buy. So I'm getting to collect the stuff I used to want and pay virtually nothing for it. I will be interested to see how decoding music into 270 surround with the Proton and then encoding it into either QS or Involve and decoding that with the Surround Master will turn out.
maybe I should make a DTS DVD demo of all the different surround decoders I have decoding the same film clip. Would anyone be interested in hearing that?
Oh, and before I forget - get a Desper Spatializer (the consumer unit). I have one and just bought another for $30 on eBay Monday. I'll tell you about it and why I bought two in another post.