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ButchDeal

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The whole philosophy of the Sansui method is based on the precedence effect summarised by a sound even if its 12 dB quieter will be perceived as the dominant direction if it precedes the louder sound by between 0.7 to 30 ms.
Are you saying that Sansui added delay on other channels as well as cut dB?
 

ar surround

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I've got a working 101A and an SMv1. In SQ mode, there's quite a bit of front-center to back-center leakage on the Involve unit - I'd say you can hear the lead vocal at about 50-75% volume in the rears when it's not supposed to be there at all. With the Fosgate, it ranges from maybe 25% bleed to almost completely silent.
Now that is interesting because virtually every decoder I've ever heard provides the greatest separation on that center front signal. When playing stereo through the SMv2, it keeps center front material solidly in the the center front. Logic7 Music pulls the center vocal slightly forward into the room, but that effect is intended. Both the Tate 101A and Logic7 can do some miraculous things, but they are also capable of turning certain material into a freak show.
 

chucky3042

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I've got a working 101A and an SMv1. In SQ mode, there's quite a bit of front-center to back-center leakage on the Involve unit - I'd say you can hear the lead vocal at about 50-75% volume in the rears when it's not supposed to be there at all. With the Fosgate, it ranges from maybe 25% bleed to almost completely silent.
I dont understand that as if you check the test table it should have around 28 db separation in that direction. SQ is very sensitive to phono cartridge phase relationships and level shifts.....there may be a problem - or we sold you a dud. I will talk to Bitch and see if we can send you a test track
 

sjcorne

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Now that is interesting because virtually every decoder I've ever heard provides the greatest separation on that center front signal. When playing stereo through the SMv2, it keeps center front material solidly in the the center front.
I'm talking only about playback of SQ-encoded material. The SM does a great job canceling center-front information in Involve Mode on both QS-encoded and plain stereo material.
 

chucky3042

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I'm talking only about playback of SQ-encoded material. The SM does a great job canceling center-front information in Involve Mode on both QS-encoded and plain stereo material.
I am referring to the SQ decode, see the table below:

SQ Test Tones results.jpg


Top line..............separation = 33.7 - 4.5= 29.2 dB front center to rear center
 

Wunlow

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That graph just posted is for the first SM SQ decoding and not SM SQ vinyl decoding, correct?
 

chucky3042

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That graph just posted is for the first SM SQ decoding and not SM SQ vinyl decoding, correct?
Ah yep correct below is the vinyl one (it does not include the center front to center back separation unfortunately (we were lazy)

1581734772817.png


Again ignore the diagonal. For example the Fr to Fl separation would be 36.2-13.9 = 22.3 db

SQ is such a sensitive shit sandwich that if you push for higher separation it starts sounding mechanical. We actually listen to the sound not just the numbers! And even though no one believes me when you are sitting in the middle the most separation you can percieve is 12 dB. Blah Blah people say they hear the bleed through but when we check it was always when listening to one speaker in isolation of other (next to it). Anyway again the magic 12 db.
 

chucky3042

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Thanks for the great & informative reply!

Well that alone is very intriguing...
Yeah once you work out what sound goes where you then need to adjust the variomatrix to enhance the separation in that particular direction. It turns out that music typically has a characteristic envelope shape with different attack and decay constants depending on what band it is in. So our variomatrix adjustments are based on dual slope techniques and different depending on which one of the tribands the music is in
 

jaybird100

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Funny that. Most of my SQ titles are Columbia with a handful of ABC Quadradisc (which as it turns out are QS) and I've never noticed any pumping.
Being that the FL to FR seperation of the SQ-W is speced at only 20 db and that my system is all seperates (Arcam FMJ C31 pre, NAD 2600A front and NAD 2400 rear) I only use the rear outs of the SQ-W. The front channels come directly from the preamp which coveniently has two sets rca and one XLR.
The problem with that is that, since you're not separating the rear signals from the front, you have less apparent separation. If you also use the front outputs, the effect will be more "discrete" than the way you're doing it.
 

bill114

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The problem with that is that, since you're not separating the rear signals from the front, you have less apparent separation. If you also use the front outputs, the effect will be more "discrete" than the way you're doing it.
That's an interesting theory. I guess you're saying that in my current configuration, there will be some information in the front channels that will be more in the rear if I use the front outputs. I do most of my listening from stereo sources and while the rear channel effect is source dependent, sometimes I get an almost spherical sound field that's pretty amazing. I'll have to try the different hookup and check out the difference.
 

bill114

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The problem with that is that, since you're not separating the rear signals from the front, you have less apparent separation. If you also use the front outputs, the effect will be more "discrete" than the way you're doing it.
Changed hookup to: preamp > SQ-W > front and rear outs > front and rear amps. Front soundstage significantly smaller and lost some flexibility balancing front to rear levels. To my ears, running preamp direct to front speakers bypassing SQ-W front outs gives a much larger sound field - I'll be sticking with that.
 

ar surround

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Changed hookup to: preamp > SQ-W > front and rear outs > front and rear amps. Front soundstage significantly smaller and lost some flexibility balancing front to rear levels. To my ears, running preamp direct to front speakers bypassing SQ-W front outs gives a much larger sound field - I'll be sticking with that.
If you like the way it sounds, well then why not? I sometimes downmix the rear channels of discreet quads into the front speakers and sit between the fronts right in the sweet spot. The result is holographic with a neat wrap around effect. Just another different way to listen.
 
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