What is Dolby Pro Logic IIx?

[Lanny_B]

As far as I've ever known, Dolby Pro Logic is faking surround from a stereo signal, but I've heard just enough about some other supposedly 7.1 format that is different? Dolby Pro Logic IIx or something?

 

[ChrisWiggles]

http://www.dolby.com/press/ce_pr_0309_plIIx.html