Decoding SQ Classical Records

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jonmchugh

Active Member
Joined
May 5, 2019
Messages
56
Location
UK
Hi all,
I'm a big fan of classical music and have recently got interested in quadraphonics, I've built up quite a collection of SQ classical records mostly on the UK EMI label in the ASD 3xxx series as their readily available in the UK.
I've not seen much on QQ about decoding classical ambient recordings so wanted to ask about other peoples experiences with it.
The 2 systems I'm using are the Audition 3.0.1 SQ Final public Script and a home made analogue CBS/Motorola IC gain-riding Logic Decoder.

Comparing the 2 decoding systems I have I'm finding the reverse of what I'm expecting and what I've been reading about on the forums, Thats the Logic decoding is giving a much better concert hall ambiance than the scripts are. I though I must be doing something wrong, I have a couple of SQ Rock/Pop records, DSOTM & AGs Angel Clair so I compared the 2 methods of decoding these, Here as expected the AA script if far and away superior in every way, Its sounds just like the discrete mixes (barring some minor artefacts) and Logic Decoder sounds poor, poor channel separation, poor smeared imaging, noticeable gain pumping - as expected.

So back to the classical, Decodes with the AA scripts just sound wrong, the rear channel ambiance is way to brutal, its sounds unnatural like a delayed reflection of the front channels and in no way sounds like concert hall ambiance. With the 70s logic decoder it just sounds right with no gain pumping or artefacts, in fact I thought the logic was not working so turned it off and the ambiance sounded flatter so the logic is doing its job just emphasising the ambiance where required.

What are other peoples experiences with classical, Could it be EMI have engineered their recordings specifically to work with the CBS logic decoders? They were made in the mid to late 70s after all.
 

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That's a good question, but I think I only have/had one EMI classical SQ album and I didn't like the music. I can't remember how it decoded using the Final script - or how it was supposed to sound - which isn't very helpful I know, but it is true.

Have you got Previn's 1812 in SQ quad? If so, what do you make of it?
 
No I don't have the 1812 overture. Its cheaply available on Discogs but i don't like it enough to want to order it.

I may have found the answer to my question here...
http://midimagic.sgc-hosting.com/quadmuse.htm
I later found out that the SQ records with ambience had the ambience exaggerated so it would get past the inadequate separation and the gain riding.
 
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Hummm...Funny you should mentioned SQ Angel classical records. I recorded from an Angel SQ encoded 45 rpm LP (Angel Sonic Series) record to 4 channel tape. I use a Sony SQD 2020 . It tends to put the bass sections of the orchestra in the rear speakers and does have separation between the two rear speakers.

I find the SQ decoding to be very good (for SQ at any rate). Recording the record to quad tape I can better reference the four channels to my liking.
 
I have not noticed the bass being sent to the rears, the bass in my setup seems very much in the front, but thats where my subwoofer is. I did not think the vinyl medium could store the low frequencies in anything other than mono/front center as the lateral oscillations would push the needle out of the grove. Having said that I do seem to get reverb of the bass instruments in the rear channels thats like the sound bouncing off the back of the hall like it should be there. Perhaps I need to listen more critically to this element.
 
What are you trying to do? 4.1 or 5.1. SQ does not rely on "ambient sound". Like CD 4, SQ places various instruments (or assigns) to a particular speaker, just not as well as CD 4. If you have a woofer in front center and two speakers in the rear you are defeating the whole idea of four channel SQ, QS, EV and CD 4.
 
Hi all,
I'm a big fan of classical music and have recently got interested in quadraphonics, I've built up quite a collection of SQ classical records mostly on the UK EMI label in the ASD 3xxx series as their readily available in the UK.
I've not seen much on QQ about decoding classical ambient recordings so wanted to ask about other peoples experiences with it.
The 2 systems I'm using are the Audition 3.0.1 SQ Final public Script and a home made analogue CBS/Motorola IC gain-riding Logic Decoder.

Comparing the 2 decoding systems I have I'm finding the reverse of what I'm expecting and what I've been reading about on the forums, Thats the Logic decoding is giving a much better concert hall ambiance than the scripts are. I though I must be doing something wrong, I have a couple of SQ Rock/Pop records, DSOTM & AGs Angel Clair so I compared the 2 methods of decoding these, Here as expected the AA script if far and away superior in every way, Its sounds just like the discrete mixes (barring some minor artefacts) and Logic Decoder sounds poor, poor channel separation, poor smeared imaging, noticeable gain pumping - as expected.

So back to the classical, Decodes with the AA scripts just sound wrong, the rear channel ambiance is way to brutal, its sounds unnatural like a delayed reflection of the front channels and in no way sounds like concert hall ambiance. With the 70s logic decoder it just sounds right with no gain pumping or artefacts, in fact I thought the logic was not working so turned it off and the ambiance sounded flatter so the logic is doing its job just emphasising the ambiance where required.

What are other peoples experiences with classical, Could it be EMI have engineered their recordings specifically to work with the CBS logic decoders? They were made in the mid to late 70s after all.

Hi Jon!
Since it's been decades I've listened to SQ Full Logic and I've never decoded SQ via PC, obviously I can't offer any new information to your question. Mainly I wanted to compliment you on your DIY SQ decoder board. It really looks as nice & neat as you can do on perf board. It's clever using the B200 board for the sub woof output. What is the smaller board next to it? It looks like you have 2, 2ch inputs, yes? A hundred years ago I built a decoder around those same 3 chips as well. But mine was a Photolume/Vista kit with PC board. I had it easier than you....

It seems like DIY is a lost art. The only other QQ'er I know that is competent at this is Ken Parsons, aka par4ken. If you have any other home projects like this please share.

And also, in your profile there is a place to list your equipment set up & other system tech data. No pressure to share, ya know, but I think it is interesting to read a little background behind a post. Also a forum thread to introduce yourself. Maybe I missed that.

Looking forward to more posts from you.
 
Hello,
The system is set up for 4.1
I don't know how to perform a center channel extraction in the analogue domain but I wouldn't bother as I don't think a center channel has any place in music reproduction
hide.gif
why would anyone need more than 4 speakers when most rooms only have 4 corners?

The decoder is modified to high pass the 4 main channels >100hz and to low pass <100hz a mono sum of FL + FR and send to the subwoofer. My thinking being that there would be no directionality encoded at that low a frequency anyway.

I do find a big sub essential for SOME classic pieces, Thinking Elgar's pomp and circumstance marches ASD 3388, Mars from The Planets Q4ASD 3002, the Thuderstorm in Alpine Symphony ASD 3173. The way it shakes the floor and the furniture, its adds to the music.

I also built a 2nd decoder which I kept pure 4.0, if i can get hold of a decent 4 channel audio capture card I will make some recordings and post some samples for critical evaluation.

PS. Profile added.
 
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Hi Jon and welcome!

I’ve never found the Sony and CBS and implementations of Full Logic (‘wave matching’ and ‘front –back logic) decoders especially good at handling ambience. Not really surprising as their gain riding circuitry was specifically designed just to force simple, easily identified, isolated sounds into the cardinal positions. They sound rather impressive on ping-pong-pang-pung type demo discs (which I guess was the point) but with anything more complex they are pretty much overwhelmed. Decoders that only use Variable Blend seem to behave slightly better with the re-creation of space.

I can’t be bothered with all the faffing about that software script decoding seems to entail so can’t comment on the effectiveness of the scripts you have been using. I suspect however that your (CBS L1 ?) hardware decoder sounds better than the scripts, not really down to the logic but to the phasey mess that the CBS circuit’s terribly crude phase shifting networks create. You could expect much the same result from an ambience recovery point of view if you just passed the encoded stereo pair through a Hafler difference network! CBS admitted as much with the better discrete 8 pole phase shifters of their L3 circuit, and although its variable blend looks a bit tricky to set up correctly, probably sounded half decent – but did anyone ever build one?

However, as a very happy owner I can vouch that the only sensible (and real time!) SQ decoding solution these days has to be the Involve Surround Master. In fact it is probably the best SQ decoder there has ever been (for all types of musical material) and will also revitalise your entire stereo collection as well! Since owning one (well several actually!), my venerable Sony SQD-2020 has long since been retired and my plans to build a dual band decoder based on the Motorola chipset have stalled (probably permanently!) despite the fact that I’ve designed and etched the boards and have all of the components sitting in a box!
 
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Yes I mean to get a surround master but the value of the Pound is at an all time low against the USD at the moment making it an expensive proposition. You don't think the SM will give me results similar to the scripts on classical?
 
Yes I mean to get a surround master but the value of the Pound is at an all time low against the USD at the moment making it an expensive proposition.

You ain't seen nothing yet - just watch it drop through the floor post Brexit!

You don't think the SM will give me results similar to the scripts on classical?

As I said, I've no experience of script decoding so I'm not in any position to comment I'm afraid.
 
It (SQD 2020) doesn't just move the bass to the rears. It places other instruments to the rear too. I've noticed that CD 4 tends to do the same. My system is Pioneer based with a few Akais and Sonys.
 
Thought I'd post an update to this one.

I've since made some refinements to the way I'm doing my script decodes of these classical LPs, Firstly I've upgraded to a much better phono stage and I've bought myself and external 192/32 DAC. I rip the LPs at 96/24 and run this through the automatic click remover on the light setting and then the SQ Final audition script. Then I high pass filter the 4ch output from the script at 100hz and low pass filter a mono sum of the original 2ch and amplify by 6dB for the sub 100hz. Then I encode lossless to DTS-HD master audio 4.1 and burn to an AVCHD disc.

The results are a definite improvement on the output of the logic decoder.
 
Then I high pass filter the 4ch output from the script at 100hz and low pass filter a mono sum of the original 2ch and amplify by 6dB for the sub 100hz. Then I encode lossless to DTS-HD master audio 4.1 and burn to an AVCHD disc.
Sounds like a lot of fun, both the journey and the destination.

Does the sub-100Hz content go to the SW channel and only to it?
 
Thought I'd post an update to this one.

I've since made some refinements to the way I'm doing my script decodes of these classical LPs, Firstly I've upgraded to a much better phono stage and I've bought myself and external 192/32 DAC. I rip the LPs at 96/24 and run this through the automatic click remover on the light setting and then the SQ Final audition script. Then I high pass filter the 4ch output from the script at 100hz and low pass filter a mono sum of the original 2ch and amplify by 6dB for the sub 100hz. Then I encode lossless to DTS-HD master audio 4.1 and burn to an AVCHD disc.

The results are a definite improvement on the output of the logic decoder.

You might want to try the Lucanu SQ Script as well, In my brief decoding and listening tests I preferred Lucanu to SQ Final. You can find links to that script somewhere here.
 
I could only find QS scripts from lucanu. Does anyone have a copy of his SQ scripts they could share?
 
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