Project: Quadraphonic system

My new project is almost finished.

My goal was to produce a setup that can play any of the old quadraphonic systems, in addition to Dolby Surround.

I now have the ability to play any of the following systems:

Scheiber*
Dynaco diamond*
Electro-Voice Stereo-4*
Dynaquad*
Sansui QS*
CBS SQ
Denon BMX (Often listed as UMX)
Electro-Voice EVX-44
BBC Matrix H
Matrix HR
UniQuad Equal Separation
Dolby Surround*
Circlesurround
Denon BHJ (Ambisonic)
Compatiquad (a system for mixing SQ, EV, and QS records on a record changer)

* Meets the Japanese RM (regular matrix) definition.

Systems to be added in the future:

Hexaphonic Tridee (has a vertical component too)
Tetraphonic 3D (has a vertical component too)

Systems to not be added:

CD-4 (I have never seen this work right. I have the equipment, but hate the crashing sounds that come out of it from used records.)
Denon UD-4
BBC Matrix E
BBC Matrix G
BBC Matrix GX
BBC Matrix HX

The last 4 are BBC experiments that were never used in actual released recordings.

I originally started the project in 1974, but soon discovered that I didn't have all of the information or equipment needed (I found out about the existence of BMX and H).

I began it again in 1990, and have been working on it intermittently since then. Everyday life, and several discoveries of errors in the calculations (among other factors) delayed the project:

- I found out I had two records in Hexaphonic Tridee
- I found several records with what seemed to be matrix H.
- I moved.
- I discovered that the decoding equations I had been given for Matrix H were in fact encoding equations. This means those records I found are in some kind of a reversed form of matrix H.
- I built the room the system is in, and wired the walls and ceiling to feed 9 speakers. I mounted 8 of the speakers in a rough octagon around the edge of the room.
- I found out about the existence of Circlesurround.
- I found out the Ambisonic encoding equations and added this into the system.
- I was laid off, and had to find another job. For a long time, I could not buy the materials I needed.
- I finalized the design in 2010, and constructed the control box.
- I had to rebuild part of the box when I discovered the output phase for the BMX and H front outputs were phase reversed.
- Make space for 3 more stereo amps and the decoding equipment.
- I put it all together Saturday. Then I switched it on and found out the stage had fallen at the Indiana State Fair.
- The system is currently undergoing testing and calibration.

I still have the following to do:

- Mount the overhead speaker to the ceiling.
- Place the floor speakers.
- Run the floor wiring.
- Wire up the last amplifier.

Equipment used:

Sherwood RD-6106 surround sound receiver
Metrotec Universal Four Channel Decoder
Archer 15-1278 Video Sound Processor
Two Realistic SA-10 stereo amplifiers and one Optimus STA-20
Four Nubian 345 speakers
Four Panasonic speakers
RCA Pro SW100P powered subwoofer

The control box takes the outputs of the Metrotec and the Archer, and combines them to produce the signals needed to feed all 10 channels for each system. Note that most of the systems do not use all ten speakers.

Once I complete the system, I will take some pictures.

About the BBC matrix trials:

In 1974 and 1975, the British Broadcasting Corporation ran a series of matrix trials to determine which matrix system (if any) to broadcast in. They tested the following matrices, labeled with letters of the alphabet:

Matrix A - Sansui QS basic matrix

Matrix B - CBS SQ 10-40 matrix without logic

Matrix C - Sansui Variomatrix

Matrix D - CBS SQ with Front-Back logic

Matrix E - A tetrahedral equal separation matrix proposed by Peter Scheiber, but never used except for these trials

Matrix F - Denon BMX

Matrix G - A variation of Matrix F designed to reduce the phasiness in stereo reproduction - never used outside these trials

Matrix GX - A refinement of Matrix G - never used outside these trials

Matrix HX - A refinement of Matrix GX - never used outside of these trials

Matrix H - A refinement of matrix HX - Used for several BBC broadcasts and a few recordings. Halfway between BMX and QS.

The trials were finished, and the BBC decided to not decide at the time. They used some QS recordings in the interim. Then Dolby Surround became the de-facto standard.

Several; other matrices have developed as a result of these trials:

Matrix HR - I don't know exactly where this came from, but it appears to be a phase backward version of matrix H. Maybe someone used the same erroneous information I got in 1982, with the decoding coefficients in the encoding equation (see first post). I have some records in it.

Denon BHJ and UHJ - a compromise between Matrix H and QS. Also called Ambisonic.

Quadities

I discovered some unexpected effects while using my new switchbox on old records:

- Most of my Abba records have what seems to be Matrix H.

- There is also a set of modulations on my Herb Alpert and the Tijuana Brass records that looks like the 4 corners of SQ. The weird part is that these records were made before quadraphonics. But there is an explanation: A&M Records was using the Moss system. This was a way to get rid of the "oversize soloist" effect when a record is played in mono.

- Most of my Vangelis records seem to be in unlabeled SQ. But the record company he recorded for had chosen CD-4.

-

Here is a picture of the quadraphonic surround sound controls:



The equipment shown includes (top to bottom):

Archer 15-1278 Video Sound Processor
The SSC-10 switcher
Metrotec Universal Four Channel Decoder
Small boxes for surround delay control and back speakers level
Dynaco PAT-4 Preamp (used for impedance and level matching)
Optimus STA-20 receiver (used as a stereo amp)
A switchbox for speaker phase
Sherwood RD-6106 surround sound receiver
Two Realistic SA-10 stereo amplifiers

Not Shown:

Four Nubian 345 speakers
Four Panasonic speakers
RCA Pro SW100P powered thumper (subwoofer)

Here is how it is connected:



The signals from the control switcher enter at top right.
The Zenith and Nadir channels are not yet in place.

Dolby Pro Logic is basically the Sansui QS matrix.

Hi R-C,
Hows a guy like me supposed to listen to this stuff ?? I only have 1.5 ear---
Ron Rich

I couldn't be bothered with all that jive...
In the 1970's when I worked as a salesman for a Stereo Salon I didn't care for 4-channel stuff.
Even the best high-end systems left me unimpressed.
And back then, I said it was a "flash in the pan" - turned out I was right.

Gimme two.... just TWO decent speakers, and simplicity of operation - that's all I need.

Matt,
Just thinking--back in the 70's I went to several "demo's" also--and I remember thinking that this did not sound any "better" to me then a good stereo--I also remembered a childhood experience, when my Grandfather used to take me to San Francisco's open air, live, BIG band "concert stand". I remember that the seats were awful hard, and it was sometimes cold, but I really did enjoy the (different types) of music, featured weekly--I can hear it now--still in my head-- Ron Rich

For me, the difference between stereo and quadraphonic was much larger than the difference between mono and stereo. But I like the sound fields that matrix makes more than the fake positioning of discrete, which tried to do side positioning by panning. It doesn't work.

The only systems I have listened to that do provide proper side positioning to a forward-facing listener were the original Dynaco system and Dolby Surround. I also used some tricks to make side positioning work for QS.

I have since learned some miking techniques that make side positioning and localization work on a QS system without enhancing logic.

The "Moss system" I mentioned earlier is actually the Haeco CSG (Compatible Stereo Generator - also known as the Holzer system, and as a process used by Jerry Moss of A&M Records). It was a system to reduce the size of the center soloist in mono playback.

This was used on records produced by the A&M, Warner Brothers, Atlantic, and Reprise labels from 1968 to around 1971, although some bands continued using it afterwards. It reproduces correctly through a BMX or UD-4 decoder, and throws the center soloist to the left back in SQ playback. "CSG Process" appears on some record jackets or labels.

There were three reasons why quadraphonic sound did not sell:

1. The recession

2. Lack of a standard. (Once Dolby Surround became the de-facto standard, sales picked up)

3. The manufacturers didn't understand what was happening. When quadraphonics first appeared on the market, the 4-channel reel-to-reel recorder sales exceeded all expectations. This caused manufacturers to quickly rush out products before the systems were perfected.

While the other quadraphonic equipment sold slowly, the 4-channel reel recorders were still selling briskly. So they developed discrete system, which also didn't sell.

They read the market wrong. TEAC was the first to figure it out: Those 4-chanbnel recorders were going into homebrew recording studios, not quadraphonic systems. The result was the Tascam line of portable studios.

After Dolby Surround became the de-facto standard, sales of surround sound systems picked up, and exceeded sales of the old quadraphonic systems.