I have a 5.1 speaker setup (pretty decent) with a Pioneer VSX-D409 reciever. It has DD, DTS, and Prologic, but not Prologic II (to my knowledge). I'm playing Grand Theft Auto: San Andreas and I was ...

Here's an excellent explanation of Dolby Surround. Pro Logic II is pretty much a refinement of Pro Logic, and although it can produce better results with Dolby Surround than a Pro Logic Decoder can, ...