So a question regarding EX. I know that EX extrapolates a matrixed SB channel from a 5.1 mix. There are some DVD's that are released with DD EX 5.1(eg. Star Wars, The Devil's Rejects) where a flag is present indicating to the receiver that there is a matrixed source on the disc itself to be sent to the SB speaker/s. (That's my understanding anyway. Please correct me if I'm wrong.)Whenever I play a DD disc, EX or not, my receiver always displays and outputs DD EX. This is fine and is how I want it. My question is this- why even bother putting an EX mix on a DVD since if someone wants that back channel they will have their receiver take care of it and turn on EX from there? Is there a difference in quality when having an EX mix on the disc itself as opposed to having the receiver do it on its own? Why doesn't Dolby, like DTS, just come out with a discrete 6.1 format already? Not a major issue obviously, just curious. Thanks.