The "Why" is actually quite easy to answer.
I have a project on the go - waiting for final go ahead from the client - where the release is to be a full DVD-A title, but also a CD version too, as they are basically a bunch of old West Coast Hippies who want to consider their entire audience and not just Audiophiles.
They are also into technology and sneaky surprises.
So, one of the ideas on offer right now is for the CD version to be Surround encoded but playable in a bog standard stereo CD player. The users will find out about the decode thing one of 2 ways:
1/. Visiting the bands website, where the info will be there, or
2/. Finding out by accident.
The DVD-A part is no problem at all, neither is the Surround mix.
Given the encoders I have available to me, what I would like to know is what one gives the best results when encoded as Lt/Rt matrix.
I could always experiment, and probably should, but I was simply trying to be lazy I guess. Discrete - no problem.
Matrixed - not used it much as I prefer discrete. Time to get practising.
The encoders I own are a straight LRCS one and the SRS Circle Surround, and I am about to order a PL II Encoder as well, but that will be a standalone one.
Ah well.
I guess I should stop trying to get others to do my research for me.