Official QQ Surround Master Test: SQ Modification

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JonUrban

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I finally got some time to sit down with the Surround Master and an SQ LP, a Q8 of the same title, and also a PC with an AA SQ Script to see what I could come up with. The results were interesting at best.

First of all, forget about either of the SQ methods equaling a discrete tape, even a "lowly" Q8. There is just no way that once you mix a bunch of stuff together you are ever going to get it all back totally whole. You can have the most complex and detailed decoding device known to man, but you are forever stuck with the ancient encoding device that was used 30+ years ago to encode the material. Fact of life.

So, here are some results, both visual and aural, of my experimenting with a track from Paul Simon's "There Goes Rhymin' Simon" LP called "One Man's Ceiling is Another Man's Floor". Not one of the hits, but one that's a good tune (IMHO) none the less.

For audio purposes, I sampled a single verse and converted it to MP3 so you could play it right from here if you like. I hope you can get something out of this little test. The results surprised me a bit, but then again, I am easily surprised! :mad:@:
 
Here is a look at all 3 4 Channel wave forms together in Sound Forge 10. Each is labeled in the title bar. You can see how the two decodes are very similar, however, upon close inspection, the script decode appears to be a bit more accurate than the Surround Master decode. That does not mean it does not sound as good, it's just that the wave forms shape from the script output more resemble the Q8.

OneMansCeiling1024-2.jpg
 
So. Conclusions? Well, this is one track, one song, and an old LP played back on an old turntable with an old cartridge. With all that in mind, I am left without a clear choice of script vs Surround Master.

The Surround Master is clearly an easier tool to deal with. Plug it an and listen! (y) That's it. The audio in the rears does not exhibit pulsing or phasing, and when listened to as a total presentation, without isolation of any particular channel, it's an excellent surround decode. Stuff comes from where it's supposed to come from. However, there is bleed through. The vocals that are only in the fronts on the discrete tape are heard fairly clearly in the rears when the rears are solo'd. The AA Script does a better job of getting that vocal out of the rears, but it's still there, and it's a bit of a pumping vocal at times.

The script seems to decode the SQ files with a better accuracy, as far as the shape of the wave forms goes. But it requires a lot of processing and user-time to create a decode. Certainly not for those who want to cue up a tune and have it play.

Neither method gets close to the discrete tape, and it's probably just not possible, for the reasons expressed in my first post in this thread. But really, I don't think anyone really expects that anyway. It's a give and take. The Q8 is better quad, the SQ LP is better audio. Another "Fact of Quad".

So, do I think the Surround Master is worthy? Hell yes! :banana:

Do I think the scripts are great? Well, Hell yes I do! :smoking

They are really two different beasts, each with their own plusses and minuses. I would not discount either one by the results I just presented, as "your results will vary". I just wanted to do a quick results posts as many of you have asked about this.

So, without further rhetoric, go forth and discuss! And let us know what YOU think of the Surround Master, the scripts, or the results of this test.
 
Excellent stuff Jon, so thanks for all the work. Do you have a Tate that you could post a similar thing of as well or pass the source file on to someone else to compare? I think that is probably the real test as that seems to be the bench mark for 'live' decoding and it is hoped that the SM could either equal or better. Thanks again for your work and from your excellent descriptions I expect it would be difficult not to agree with your conclusions too!
 
Excellent stuff Jon, so thanks for all the work. Do you have a Tate that you could post a similar thing of as well or pass the source file on to someone else to compare? I think that is probably the real test as that seems to be the bench mark for 'live' decoding and it is hoped that the SM could either equal or better. Thanks again for your work and from your excellent descriptions I expect it would be difficult not to agree with your conclusions too!

Sorry. I no longer have a Tate to try. I actually never had a Tate II. What I had was an orignal Tetrasound unit, which pre-dated the Tate. Unfortunately, I paid to have it "restored" (ugh) and it did not survive the restoration. It now sits in a box and is useless. Not even worth firing up and giving it a shot.

If someone wants to try this track through a Tate II into their PC and post the results, that would be great. Otherwise, we'll have to make due without that comparison, which would have been nice to have here.
 
Sorry. I no longer have a Tate to try. I actually never had a Tate II. What I had was an orignal Tetrasound unit, which pre-dated the Tate. Unfortunately, I paid to have it "restored" (ugh) and it did not survive the restoration. It now sits in a box and is useless. Not even worth firing up and giving it a shot.

If someone wants to try this track through a Tate II into their PC and post the results, that would be great. Otherwise, we'll have to make due without that comparison, which would have been nice to have here.

The Tetrasound units used the Tate IC's - the original National Semiconductor chips. It was the model 101, thus the Tate II was the 101A. Who was the person who destroyed the decoder in their attempt at restoration?
 
Hi Jon

Thank you for your detailed tests and I agree with your conclusions. As I have consistently stated SQ is a very difficult format to decode and it is VERY phase and level sensitive. If either of these are slightly out the results are poor. Unfortunately most SQ material is on disc and such issues are the norm.

I do hope all those who have purchased the SQ/ QS/ Involve version of the Surround Master have a great time re exploring their SQ music collections. The design process was 10 times harder than we anticipated but in the end it was personally very satisfying and frankly the material we have tested sounds much better than I expected considering what a mess SQ is!!!!!

Regards

Chucky
 
Hi Jon

Thank you for your detailed tests and I agree with your conclusions. As I have consistently stated SQ is a very difficult format to decode and it is VERY phase and level sensitive. If either of these are slightly out the results are poor. Unfortunately most SQ material is on disc and such issues are the norm.

I do hope all those who have purchased the SQ/ QS/ Involve version of the Surround Master have a great time re exploring their SQ music collections. The design process was 10 times harder than we anticipated but in the end it was personally very satisfying and frankly the material we have tested sounds much better than I expected considering what a mess SQ is!!!!!

Regards

Chucky

Chucky,

What you guys have done is actually quite astounding. When you consider that you spent the time and effort and managed to create a very effective SQ decoder in 2013, and then basically retrofit all the existing Surround Masters for free to their owners, it's hard to believe.

Back in the '70s, I hated SQ. To me, it was a large part of the downfall of quad. The decoders were horrible at the format's launch. Many a cheap receiver had an 'SQ' button that did little. I can imagine that many an enthusiast got their new quad system home, fired up an SQ LP, and were totally underwhelmed. I know I was. Comparing a Q8 to an SQ LP in 1973 was laughable. CD-4 was far superior, but it had a lot more baggage. The cart, the turntable, the calibration - THE COST. It was impressive, but it wasn't easy to get going. Matrix was cost effective, but very depressing. By the time the Tate came along, SQ on LP, and quad itself, was done for all practical purposes.

Anyone that still has a collection of SQ LPs should seriously grab on of these units, as it will do the job far better than anything they can get on eBay, and it's new and modern. It is clearly an easy and viable alternative to processing SQ recorded files using AA scripts.

Again, thanks for the effort and accomplishment. You did good :), and our membership will obviously reap the benefits. As I said earlier in the forum, you really should get a unit over to SOUND & VISION magazine for them to test. Those guys are still surround aware and would probably love to try it out.
 
For anyone still on OD's blog, the entire of There Goes Rhymin' Simon was decoded as DS171f, and I'm seeding it. This used the complete version of SQ*Final, the version of the script OD released was cut down in some way from what I understand. Don't know how much difference that would make, but the decode is there for anyone that has it or wants to download it for comparison.
 
Please do a comparison using the 5.1 outputs - I'd like to see how different they are from the 4 channel outputs since the 5.1 don't decode SQ strictly correctly - for example, LB and RB may be in the center channel since SQ encodes them in mono with phase shifts, and are the backs removed from the L/R front too? Don't get me wrong, I'm not criticizing the decoding, I'd just like to see the waveform/separation results using the 3 front outputs. A test record might be best to show the results - I have no way of doing such a test due to an old PC.
 
Hi Jon,
I was wondering if you could make available the original SQ encoded source used in this test. It would help me to compare the performance of my new multiband shadow vector decoder compared with the Involve and the script method.
Additionally any test material (short or long) in both Discrete and raw SQ would be very useful. If also available in decoded Tate and Script even better.
Hope you can help.
Malcolm
 
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