QS Regular Matrix

Quadraphonic Sound (originally called Quadphonic Synthesizer, and later referred to as RM or Regular Matrix) was a matrix 4-channel quadraphonic sound system based on the same principles as laid down by Peter Scheiber, but developed by engineer Ryosuke Ito of Sansui in the early 1970s.

It was adopted by ABC, Advent, Bluesway, Candide, Command, Decca, Impulse, Longines, MCA, Pye, Turnabout and Vox record companies. It was freely licensed to record companies.

The concept of Regular Matrix was often used a synonym to QS, but was actually a standard set by the Japanese governing body, which also embraced the QM and QX matrix systems.

The QS matrix has been found to offer the advantages of excellent diagonal separation and stereo compatibility, and although the adjacent speaker separation is only 3 dB, this symmetrical distribution produces more stable quadraphonic images. The QS record track is as small as a conventional stereo track, so the maximum playing time is the same as conventional stereo records.

As early as 1969 engineer Peter Scheiber developed a matrix system very similar to QS. He also was instrumental in many improvements to SQ (see above) quality, in collaboration with Martin Willcocks and Jim Fosgate.

In the early 1970 Sansui introduce the Four Channel Synthesizer Decoder QS-1 and the QSE-1 Encoder based on the QS system in Japan and debuted export to the United States in March 1971. The channel separation was only 3 dB, but because of the human way of hearing it sounded relatively good.

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