Quad and Surround speaker layouts switching

[afalout]

Folks,

been working for a while (mostly in my head) on creating a switched speakers layouts - that would cover all commercial Quad/Matrix layouts and also allow me to switch between Quad/Martix and "modern" Surround (ITU/Dolby).

First attached diagram focuses on layouts, and second one on switching/patching AVR, Quad systems and amps/speakers.

Probably should had asked before I started, but better late then never. So:

1) How do you approach/handle the speaker layout differences in different Surround/Quad formats?
2) Any feedback on attached diagrams gratefully received.

Thanks,
Andrej

 

[proufo]

Lo-res images, I believe.

 

[afalout]

Lo-res images, I believe.

I did post them as hi-res, and posted the same in FB group. They are fine there, not so fine here. Seems QQ forum software resamples images on upload? Bummer....
Anyway.... question remains the same - how do you do your speakers layout switching?

 

[proufo]

Anyway.... question remains the same - how do you do your speakers layout switching?

Not sure if this is what you request, as it is too simple, but here it goes. The hi-res images would be useful.

- You can use 4 identical speakers (rears to the sides, not behind you) and a similar center speaker for Quad/mch music. You can choose to live with that layout for 5.1 movie surround. It is suboptimal for movies, as the side surrounds will not always merge nicely (in my experience).

- You can use a speaker switch to alternate between the Quad/mch "rear/side" speakers and proper side movie-surround speakers.

- You can have two preamp/processor and rube-goldberg a system for both music and movies. That is my case.

 

[afalout]

Hi Pablo, and thank you for your reply;

Diagrams attached as Zip file to protect them from resampling.

Diagrams depict a speaker layout switching system. The goal is to:

1) for each format supported, have means to select correct/intended/specified speaker layout
2) be able to ABX compare spatial imaging of various formats, while using corresponding speaker layout without physically moving speakers, using remote control, from the listening position. In real-time, using a single button on a remote.

Think of playing Quadrafile records on two TTs, one playing, say, SQ side, another one QS. For example. Or playing Quad R2R tape, RM LP and SACD quad transfer. Or Atmos mix and ... etc..

Obviously, for each format, apart from the appropriate playback/decoding chain (which is equaly obviously not on these diagrams), a specified speaker layout is needed. Otherwise, the results will be a soup of random sounds comming from random more-or-less inaccurate and unintended places....

So the goal is not to create a compromise speaker layout, but how to create correct/intended/specified layouts that one can switch between on demand.

This is is what I came up with, and I'm wondering what other people are doing to accomplish the similar goals. Should they have such goals.

Also, any feedback on my design is gratefully received.

Cheers,
Andrej

 

[proufo]

Very ambitious!

I suppose everything is possible with enough Zektors and RCA splitters. Of course you would need a large cheat sheet to manage it all ;-).

I wonder why the Pentagon and Diamond-Dolby Surround layouts do not have all speakers equidistant from the listener. And if they are to be not-equidistant, why not put the sides (in you case rears with over 110 degrees, why?) farther instead of closer, for a more diffuse presentation?

 

[afalout]

7 Zektors to be precise, but who's counting? Yup, already created a cheat sheet, I need it for Harmony activities programming.

Regarding your question - and I should have noted that in advance - the big circle of speakers does not represent the actual speaker layout(s). It is there only to visualize speaker connections. The actual physical layouts will correspond (conceptually) to the images next to each system, in a upper left table of "Layouts" image (which was mistakenly labeled "Patching" when uploading)

With one notable difference, which is suggested by the red square around the listener icon - and that is, the rear speakers will not be behind the listener (as indicated by Wendy's "worst Quad/surround setup", but to the side, only slightly behind (as shown on "Maximum side/rear separation". So 30+65=95 degrees or so. The thing is with DS, that according to spec and licensing requirement, rear channel(s) must be delayed by 20-30 ms (and hi-passed below 7khz, and have Dolby B applied). I have one decoder (Proton) that can turn those off, and another one H/K Citation) that can't. I expect that the 20-30 ms delay will deliver exactly the results you suggested. We'll see. And this is why...

...the first thing I will do with the fully completed setup, will be ABX listen with encoded materials as A, and matching discrete source of same recording as B - that will determine the final layout I will use for each format. And this is the reason why the big circle of speakers does not represent the final positioning of each speaker. I will not be able to finalize this until I can hear what impact of the decoding (and processing) has compared to the source...

Muddling the water here is the fact that almost all studios that produced Quad material in 70's had used the "worst" layout - equidistant square - to do monitoring of the mix. But not so for DS, which enforced there rules and even had mandated that Dolby "consultant" be present on sessions that want to produce releases that bear Dolby Surround logo...

So to be honest I'm not sure what to expect. Proof will be in the pudding.

 

[proufo]

At least one manufacturer of Quad equipment, Lafayette, suggested a rears-to-the-sides approach.

 

[par4ken]

At least one manufacturer of Quad equipment, Lafayette, suggested a rears-to-the-sides approach.View attachment 50114

That is how I usually like to place my speakers, it's almost the only way in a typical living room. Six feet apart for the rears seams a bit close, twelve or more feet would be better. Set up the fronts for perfect stereo imaging. The rears will image much like headphones and will be too loud if placed to close to your listening location.

 

[MidiMagic]

I did it with a Pro Logic II receiver with a discrete input.

The 4 big speakers went in the 4 corners, connected to the 4 speaker outputs of the receiver. I do not use the center channel or the subwoofer outputs, but derive them separately.

I then put in 4 smaller speakers between the others at center front, left wing, right wing, and center back. Each has a small amp.

The final step was to build a switch box to select various matrix decodes for each speaker. The small speakers could be switched in with the selector panel or turned off. The large ones were switched as a group between the Dolby decoder and the switch box.

The switch box can select from several matrix decoder outputs (including SQ) to feed any of the 8 speakers. Blending pairs are also provided, along with L+R and L-R.

The subwoofer is derived from the sum of the stereo channels before the decoders.

 

[fredblue]

interestingly, by 1976 CBS was recommending two main layouts for SQ Quad; one for a "Vivid" experience and one for "Extended Listening".

"Vivid" was a square 4-corner arrangement (more rectangular really, with the Front to Back dimension slightly greater than Left to Right) and "Extended" (while still a 4-corner layout) was a 'horseshoe' or as they call it "semi-circle" with everything spread right out across the room in a rectangular fashion.

Pics to follow.

 

[fredblue]

interestingly, by 1976 CBS was recommending two main layouts for SQ Quad; one for a "Vivid" experience and one for "Extended Listening".

"Vivid" was a square 4-corner arrangement (more rectangular really, with the Front to Back dimension slightly greater than Left to Right) and "Extended" (while still a 4-corner layout) was a 'horseshoe' or as they call it "semi-circle" with everything spread right out across the room in a rectangular fashion.

Pics to follow.

info taken from the "New Quadraphonic Gala" Sampler (SQ LP, CBS 1976)

Front:

Rear:

Detail:

 

[afalout]

Thanks @MidiMagic - and thanks for your web site

Is this your current system you where describing: Quadraphonics

What do you think about what I am working on?

 

[afalout]

Thanks for this @fredblue , very interesting.

Seems to me that they are indirectly saying that "anything goes". I find the proportions in these pictures unlikely to bring much joy, based on my experiences. But maybe I need to step back and listen with a fresh head...

I am seriously considering doubling the number of speakers to 24 for initial listening tests, and A/B testing each format out with multiple recordings on multiple layouts - before committing to a particular one. Except for Dolby formats. Maybe even leave them afterwards for a (half or) proper Ambisonic sphere? But if I do that, and knowing myself, I would probably just keep flipping the layoput switches instead of listening to the music....

However... I have a dilema; how heavy does a listener need to be, to qualify as a "heavy listener"?

 

[afalout]

So here is what I'm playing with today; attached as PNG and also same as ZIP file to protect from resampling.
See notes above the diagram.

Comments appreciated.