Originally Posted by apple-q
Not sure what you're asking? You want to emulate the dolby system without an analog box or a DAW using "modules" that were used before dolby-stereo was invented?
I'm indeed aiming on the current boom in terms of surround mixing tools and the need to also provide a compatible 2.0 mix. I digget around on the net a bit, asked a couple of plugin providers in that section and it was always like "just to a Lt/Rt mix, the values are known - a hardware DPL Decoder does a realtime check".
I only wanted to know what's behind it and why some say "just mix it", other sources say "there is a phase shift involved" and even more sources say "use a dedicated plugin".
I think danijel is right, I should simply forget it. But the time M/S came up, it was also some mystery - now it's common knowledge. Guess I'll simply trust the surround tool developers to provide proper downmix parameters. Because I can't find that (indeed interesting) IRT downmix plugin, only the PDF hinting at it. And... I don't use PT, else I'd get Mix 51.
Thanks anyway for the help.