Sansui QS vs Synthesize Surround. What's the difference?

[gvl_guy]

I have a QRX-9001 which, of course, has a QS position for matrix decoding. But it also has both a Hall and Synthesize button. (I'm not a fan of the Hall setting.)

There is definitely, to my ears, a difference between playing a stereo recording in QS mode vs Synthesize mode when it comes to faking surround. Can someone explain why? Without getting too technical for my limited matrix understanding brain, what happens to make it sound like there is more separation?

(It's probably the reason why I don't use my Surround Master more for synthesizing stuff.)

 

[Sonik Wiz]

I have a QRX-9001 which, of course, has a QS position for matrix decoding. But it also has both a Hall and Synthesize button. (I'm not a fan of the Hall setting.)

There is definitely, to my ears, a difference between playing a stereo recording in QS mode vs Synthesize mode when it comes to faking surround. Can someone explain why? Without getting too technical for my limited matrix understanding brain, what happens to make it sound like there is more separation?

(It's probably the reason why I don't use my Surround Master more for synthesizing stuff.)

In the Synth mode Sansui puts some opposite phase blending before decoding. With stereo that creates a 270 deg or horseshoe sound field. It makes stereo input more like a QS sound source.
This opposite phase blending can be done on a PC or with hardware for a spectacular result with the SM.

 

[gvl_guy]

In the Synth mode Sansui puts some opposite phase blending before decoding. With stereo that creates a 270 deg or horseshoe sound field. It makes stereo input more like a QS sound source.
This opposite phase blending can be done on a PC or with hardware for a spectacular result with the SM.

Cool. Well, that explains why it sounds so good on stereo sources, better than in QS mode or with my Surround Master.

If I did the whole computer thing, I'd try it. But I'm more of a physical media guy. Limited material, but much easier.