INVOLVE SQ - IS HERE

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Speaking of balance. I have run into several SQ albums where the whole thing was mixed slightly imbalanced. If I set balance for equal Front Left and Right, the rear information would be wrong and bleed over to the front. Now, I just spot check before playing and balance by listening to the front channels and adjust for minimum rear-to-front bleed. I seem to remember one of the Neal Diamond SQ LPs being like that. It was pretty bad off - like 5 or 6db out of whack in the front.
 
chucky3042 said:
Hi All

We have been busy examining this controversy today and as it turns out we/ you may all be correct, we have a confusing picture.

First we used 3 test QS and SQ sources for our tests these can be found in this dropbox:

https://www.dropbox.com/sh/3jpgx0qhaxcfgzy/FiiHs7DykE

Please download these.

The SQ Q4 Vinyl test tones.wav is the CBS Q4 test disc and is as the name suggest recorded on vinyl.

The SQ test tones.wav is a "script" based series of tones and is 100% accurate in terms of magnitude and phase - "by the book"
Its test tone sequence is:
Centre Front - Right Front - Centre Right - Rear Right - Centre Rear - Left Rear - Centre Left - Left Front - Centre Front

The QS test tones.wav is also a "script" based series of tones that are 100% accurate in terms of phase and magnitude- also "by the book".
Its test tone sequence is:
Centre Front - Left Front - Centre Left - Rear Left - Centre Rear - Right Rear -0 Centre Right - Right Front - Centre D

Also included below are the test results we obtained from a Surround Master randomly pulled out of stock.

Please note for our tests today we had a noise floor of -42.2dB we actually needed more dynamic range for comprehensive results but the results are fine for what we are testing.

The results for the QS script are remarkably symmetrical showing a separation of generally better than 35 dB, this reduced to approx 13 dB for central sides. Level discrepancies were less than 0.5 dB. In short it looks like all levels are balanced for SQ and Involve mode.

Now things get more interesting:

For SQ test tones.wav script based encode again the results were very good showing very symmetrical results with 30- 35 dB separation, the worst results were as expected (for SQ) the side center symmetry that showed the center side position could be pulled to the rear by about 10dB. This is one of the week aspects of SQ. It is one of the reasons SQ cannot achieve stable side central images (unlike QS- perfectly linear). In short- no sign of problems with the correct encode format.

For the Q4 Vinyl test tones.wav the results are relatively poor showing a leakage of fronts to rear amounting to only 9 - 12 db separation IN THAT DIRECTION - all other directions the separation was better than 25 dB.

So TAB - YOU ARE CORRECT!!!!!!!!!!!

Now the issue is WHY?

Upon examination of the CBS Q4 test disc we found that the encode was in error. SQ largely picks direction based on Left/ Right inter channel leakage. We found leakage in the L/R channel of say -15db and a phase error of 45 degrees. On the script based encodes these parameters are precise. This CBS disc was recorded from vinyl onto CD and it is most likely this leakage and phase shift is typical of most magnetic cartridges and RIAA equalisation curves.

At the time of developing the SQ Surround Master we were under significant "pressure" from you know who- the great Oxforddickie to ensure we were in fact decoding "BY THE BOOK". Well folks the test results today clearly show if the encode source is correct (as it will be for script based sources supplied by Oxfordickie and Bob Romano) you will get the full 35 db separation in all directions. For Vinyl sources (yes I fully accept this is the majority) the results will not be as good and dependent on how good your magnetic cartridge is in terms of separation and phase shift.

All our development work was with the script based encode sources and not with the Vinyl as we wanted to be "by the book". We note that most users of the SQ SM have reported as good or better results than the Tate yet now we have 2 users who clearly prefer the Tate. I suspect this is for 3 main reasons.

1 Given the non script - vinyl sources used they were only getting say 9 - 12 db separation in the front leak to rear direction.
2 Our previous (and controversial) tests indicate test audiences cannot pick separations above 12 dB and so clearly we fall under this and any other level issues such as amplifier pot mismatch, seating centrality, speaker sensitivity will tip the system over the edge so you will clearly notice the leakage.
3 Some people are more sensitive to separation than others - for example I listen more to things such as clarity, transient response and am less picky on separation.

Also the bulk of the users who state that they prefer our SQ SM to the Tate have reported issues of clarity and transient response. This observation is a direct result of the SQ SM being a full tri band decoder unlike the Tate that is single band.

SO WHAT ARE WE GOING TO DO???

Looks like the Tate (being designed in the late 70's) was designed specifically with vinyl in mind and has been adjusted to allow for a much smaller level sensing range (it pushes harder to the edges) than the SQ SM that has been designed for script based encoding.

I offer the following:

1 Fully money back upon return of the SQ SM if unsatisfied.
2 We will schedule some research time in say 2 months to review the internal settings of the SQ SM to have it optomised for vinyl not script - for those who want it.
3 We will send an updated memory chip in the mail to all those who want the revision - so it can be installed by a qualified technician. Probably $20
4 We offer a free update if you pay for the return transport to our factory.

WHAT NOW?

We will continue to offer the existing SQ SM for sale as I really think it is the most accurate for script based encodes but hopefully we will offer two setting versions in a few months time. My recommendation is patience but remember the version set for vinyl will not be as linear as the current version and may be more prone to pumping (as several Tate users have reported). SQ is a VERY fiddly format and is not forgiving on encode source errors- unlike QS, unfortunately there is no "one size fits all" solution.

I know this is an imperfect solution but on the bright side at least our decode is "by the book".

Regards

Chucky

So the purported spec of the cart I am using is 22db of seperation, is this suficient for the script to decode properly?
 
Hi Q8

Properly prepared script from sources like Oxforddickie or Bob Romano will decode perfectly with in excess of 35 dB separation. As for Vinyl your cartridge should be fine.

I visited Rustyandi's surround dungeon yesterday to loan his Audionics Tate decoder for comparison checks and we and his mate Warren listened to several SQ tracks played on his moving coil cartridge and when sitting down in the listening area none of us could detect any separation differences between the SM and the Tate. On some tracks IF WE TURNED OFF THE FRONT SPEAKERS we then could hear the leakage of front to back. I also note that no pumping could be heard on the SM but it could be heard on the Tate.

Additionally Warren and I could hear the clarity difference between the SM and the Tate. Warren remarked the Tate sounded like someone put a blanket over the sound. Rustyandi is less sensitive to the clarity difference but as I have stated before we all tend to focus on different aspects of the sound-I am sensitive to clarity, dimension and pumping and frankly I focus less on the separation, but that is me.

Regards

Chucky
 
Also one thing that I never have asked but have been cutious about: Why is the audio level a tad lower in SQ than in Involve?
 
Also one thing that I never have asked but have been cutious about: Why is the audio level a tad lower in SQ than in Involve?

I'll field this one, since Charlie is drooling into a bucket. There's nothing wrong with him, he just likes doing it.

When we originally created the Surround Master with the Involve decode for surround, the amount of output signal to input signal was always around 1:1. This had the effect of making Involve surround sound quieter because it was the same amount of signal spread between the 4 channels, and there was a management decision to increase the Involve decode output just enough so that when the inevitable a/b between stereo and involve decode was done, the level shift wouldn't take attention away from the actual decode. So we didn't want that distraction when it was being reviewed / demonstrated / etc.

With the SQ edition, having been created primarily for the enthusiasts and nutcases (I say that lovingly by the way) there was no need to adjust it, plus we decided that the enthusiast crowd would prefer that accuracy of sig-in to sig-out ratio. Also a certain nameless quite-enthusiastic enthusiast would have never let us live it down.

Cheers
~David
 
I really enjoy my SM in its current state but, if you intend to update it, by all means let me know. I would love to get it to the most complete version whatever the cost. I use mine everyday and have been so happy with the results that I can't imagine it getting any better.
 
Charlie: This was making me think. Would it be possible to do more chip variation units of the Surround Master? Like a Perfect SQ/Vinyl SQ version? Or even one For someone with an existing SQ surround master like Involve TSS/Vinyl SQ. You also mentioned you could convert TSS to a headphone system. I probabably would never use regular TSS, but if a headphone version worked well, I would use that a lot. Too bad that the design is probably set in stone for the Pro model, cause these are more settings it could have. And unlike most Dolby sound field settings, they would actually be useful! I know you have a two chip limit on the regular SM.
 
After reading more about the Tate and the level control with three indicators, I'm guessing variations in level as well as balance would affect SQ decoding. When I finally order one I'll be using a preamp with those controls so I'll play around with them if necessary.
 
Charlie: This was making me think. Would it be possible to do more chip variation units of the Surround Master? Like a Perfect SQ/Vinyl SQ version? Or even one For someone with an existing SQ surround master like Involve TSS/Vinyl SQ. You also mentioned you could convert TSS to a headphone system. I probabably would never use regular TSS, but if a headphone version worked well, I would use that a lot. Too bad that the design is probably set in stone for the Pro model, cause these are more settings it could have. And unlike most Dolby sound field settings, they would actually be useful! I know you have a two chip limit on the regular SM.
 
Hi Q8

Here is the problem. The Surround Master has 3 memory chips that store the programs, these are:

1 QS/ Involve decode all 4.1 outputs
2 QS/ Involve decode fronts + center (for the fools that like 5.1) - outputs of this goes to its own dedicated RCA outputs
3 TSS

In the SM SQ unit we substituted the SQ 4 channel software for the TSS software. So for example if you correctly decide not to go 5.1 we could do a unit that had QS/ Involve/ SQ/ Heasdphone virtualiser (out of the 5.1 output L and R)

5.1 was quite a bit of work for us as it was really hard to separate the center channel without producing nasty effects but it does give future options. Or as you suggest we can substitute The TSS software for headphone virtualisation (when we do it).

Just a reminder for all that if you insist on being silly and want a center channel for SQ on the SM your best option and a good approximation is to use the SQ leff/ right outputs from the 4.1 side of outputs but use the Center (that is QS decode) from the 5.1 side of the box. Turns out the center decode for SQ and QS are similar.

I hope this has confused you guys as much as me.

Regards

Chucky


Charlie: This was making me think. Would it be possible to do more chip variation units of the Surround Master? Like a Perfect SQ/Vinyl SQ version? Or even one For someone with an existing SQ surround master like Involve TSS/Vinyl SQ. You also mentioned you could convert TSS to a headphone system. I probabably would never use regular TSS, but if a headphone version worked well, I would use that a lot. Too bad that the design is probably set in stone for the Pro model, cause these are more settings it could have. And unlike most Dolby sound field settings, they would actually be useful! I know you have a two chip limit on the regular SM.
 
If there were two versions...keep the existing one for the purists and do an SQ vinyl version with a "Turbo Involve" setting (like the Sansui synthesizer setting).

I CAN DREAM, CAN'T I?? :D
 
chucky3042 said:
Hi Q8

Here is the problem. The Surround Master has 3 memory chips that store the programs, these are:

1 QS/ Involve decode all 4.1 outputs
2 QS/ Involve decode fronts + center (for the fools that like 5.1) - outputs of this goes to its own dedicated RCA outputs
3 TSS

In the SM SQ unit we substituted the SQ 4 channel software for the TSS software. So for example if you correctly decide not to go 5.1 we could do a unit that had QS/ Involve/ SQ/ Heasdphone virtualiser (out of the 5.1 output L and R)

5.1 was quite a bit of work for us as it was really hard to separate the center channel without producing nasty effects but it does give future options. Or as you suggest we can substitute The TSS software for headphone virtualisation (when we do it).

Just a reminder for all that if you insist on being silly and want a center channel for SQ on the SM your best option and a good approximation is to use the SQ leff/ right outputs from the 4.1 side of outputs but use the Center (that is QS decode) from the 5.1 side of the box. Turns out the center decode for SQ and QS are similar.

I hope this has confused you guys as much as me.

Regards

Chucky

These are some good sounding options!

How well do you think the Headphone TSS will work? I know it won't be a Smyth Realizer with head position doo dads and elf magic and whatnot but do you think you can beat Dolby headphone? Dolby headphone works OK but you have to train your brain by listening to test tones to get the best results.
 
Hi Q8

My best guess is that we would do a better headphone surround virtualizer than Dolby's without the features of the Smyth. On advantage I would claim over all others is that the surround channels would be extracted from the stereo via the Involve decode- that we claim is the best. So the end surround decode/ virtualizer presentation from stereo or quad (even the dreaded SQ ) would be superior.

We might have time to look at it when we do a Vinyl optimized SQ revision - give us a month or two.

Regards

Chucky
 
These are some good sounding options!

How well do you think the Headphone TSS will work? I know it won't be a Smyth Realizer with head position doo dads and elf magic and whatnot but do you think you can beat Dolby headphone? Dolby headphone works OK but you have to train your brain by listening to test tones to get the best results.

Even if you don't use the head positioning, the Smyth is hard to beat for true Surround imaging with a set of quality headphones. Just amazing.
As for Dolby Headphone, I've never found that one to be convincing.
 
Hi Wappinghigh

If you intend to play a bunch of SQ Vinyl and you suspect your phono cartridge has poor or not great separation then yes wait till we have the phono optomised SQ SM. Please remember that the revised SQ SM software is not really an upgrade (in my opinion) as there will be a cost of more pumping as many users report for the Tate unit.

Overture was talking to Rustyandi this morning and it was mentioned that Rustyandi has both a very high cost MC cartridge and a really high tech laser based cartridge. In both instances you would expect very good separation and so he has not had noticeable problems with front to rear leakage on SQ (Rustiandi please correct me if this is a false statement).

I remember back in the 70's (sucks being old) there were several well reviewed cartridges like Empire that when I looked at the channel separation graphs showed only around 12 dB separation- yet no one complained about a lack of stereo (remember our 12 dB findings). The vast bulk of reviewers on QQ have not reported hearing issues with separation and have generally preferred the SM SQ to the Tate which somehow tells me their cartridge have really good separation. I am not saying that separation is the sole criterion for evaluating phono cartridges, as I stick by my claim that for general stereo listening anything more than 12 dB is in fact generally undetectable. I am saying that SQ is a very level sensitive format and 2 or 3 dB can really throw it.

So wait if you have doubts about your cartridge or play a lot of SQ vinyl.

Regards

Chucky

Chucky,
I have an Audio Technica AT 15 SS, known for good seperation. Never had a problem with stereo, SQ,QS, nor CD-4 seperation.
When you develope the new chip, please incllude instruction in cluding any precautions. Thanks.
 
Hi

Will do.

And over 10,000 views to his thread!!!!

Regards
Chucky

Chucky,
I have an Audio Technica AT 15 SS, known for good seperation. Never had a problem with stereo, SQ,QS, nor CD-4 seperation.
When you develope the new chip, please incllude instruction in cluding any precautions. Thanks.
 
chucky3042 said:
And over 10,000 views to his thread!!!!

That's great! Coming here seems to have been great for publicty!
 
When you develope the new chip, please incllude instruction in cluding any precautions. Thanks.

+1

I'd be game to try DIY. I suspect the DSP is hard soldered to board but IF there's a socket, gosh, that would make it nice to switch them back & forth based on source and/or desired effect.

Chuck, maybe in a new model you guys could have a 3 way switch & 2 chips or 2 software modes. Just thinking out loud.

But I'll take whatever you come up with ;)
 
(Emmmm, going to add some levity (I hope) to the SM board)

Now that it is almost autumn for you guys and my part of Blighty is still under water: Any chance of an octophonic or hexadecaphonic SQ decoder? It would mean that I could get another two amps into my stack and avoid having centre front. We could have the ordinals or duplicates height separated to give 360 degree sound. :)

I guess that Chucky will now blow a fuse and Overture will be found sobbing into a cold one later. Sorry (enjoy the cold one though).
 
Err actually we own the trademark, infinity (the symbol).1




(Emmmm, going to add some levity (I hope) to the SM board)

Now that it is almost autumn for you guys and my part of Blighty is still under water: Any chance of an octophonic or hexadecaphonic SQ decoder? It would mean that I could get another two amps into my stack and avoid having centre front. We could have the ordinals or duplicates height separated to give 360 degree sound. :)

I guess that Chucky will now blow a fuse and Overture will be found sobbing into a cold one later. Sorry (enjoy the cold one though).
 
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