That's interesting!
curious why the LR sides are hard panned, but the LR rears are not?
Thx!
For the same reason the LF-RF are not hard panned.
This is the panning diagram for Dolby Surround. It will do for QS,
When the panpot is all the way to the left, it is encoding straight left, whether or not the front or back phasing is selected.
The LF and RF pan setting is such that the dominant channel gets 0.92 of the signal and the opposite channel gets 0.38 of the signal. These are the QS front coefficients.
The LB and RB pan setting is such that the dominant channel gets 0.92 of the signal and the opposite channel gets 0.38 of the signal. These are the QS back coefficients.
Let's pan a sound all around the room while decoding in QS so you can see:
Start with pan control full left with 3/4 button released. This is left side.
Turn pan control 1/4* clockwise. Sound moves forward to left front speaker.
Turn pan control to center. Sound moves right to center front position.
Turn pan control 1/4* clockwise. Sound moves right to right front speaker.
Turn pan control fully clockwise. Sound moves backward to right side.
Depress 3/4 button, selecting back half of the encoding. Sound is still right side.
Turn pan 1/4* anticlockwise. Sound moves backward to right back speaker.
Turn pan control to center. Sound moves left to center back position.
Turn pan 1/4* anticlockwise. Sound moves left to left back speaker.
Turn pan fully anticlockwise. Sound moves forward to left side.
Release 3/4 button, selecting front half of the encoding. Sound is still left side.
* The exact position of the pan control for encoding to any of the 4 corners differs by mixer design and must be found experimentally. It is approximately 1/4 turn, but often the knob points straight left or right. I do it by ear.
I have been doing this for 22 years.
I don't want an encoder that plays with the image positions. I want this straightforward system.
I have done SQ encoding with a similar mixer and an SQ decoder.