Matrix H was undecodable by any other means than by a matrix h decoder, which never really existed for the consumer. There was a kit available but as it was just based on qs its performance was sub standard.
I can use phono stylus vector maps and the Poincare sphere to show the intercompatibility of these systems:
I will use the Hafler diamond and DS to explain the system, because they have the same diagrams.
The left diagram shows the phono stylus motion vectors for both Dolby Surround and the Hafler diamond.
Left (cyan) and right (red) are the 45-45 stylus vectors of the Westrex system.
Front (olive) is the mono record vector, center in stereo, and front in DS and Hafler.
Back (violet) is the back channel in both DS and Hafler. It is L and R out of phase.
Ignore the brown and black for now.
On the Poincare sphere, each possible 2-channel modulation is on the sphere surface.
Left is on the far side of the sphere (large dot). Right is on the near side (small dot).
Horizontal modulation is on the right limb. Vertical modulation is on the left limb.
Scheiber, RM, and QS are interleaved between the DS and Hafler modulations
LF is green, RF is yellow, LB is blue, and RB is magenta.
EV-4 has wider front encode and narrower back encode separations:
Also, the EV decoder has different matrix parameters from the encode ones:
The DQ encode parameters are only slightly different from the EV ones.
The DQ decode parameters are quite different:
Since the record groove can contain any of these, playing one back through a different decoder will place the sound image found in the encode diagram in the same location in the diagrams in the decode diagram, with the3 image shifted as the decode diagram places it.
My passive decoder can decode any of these.
Continued next post.