Originally Posted by Head Injury
You get that, too. Pro Logic is an option under Digital Live.
I'm not sure exactly how that would work out.
My understanding is that the Pro Logic family of Dolby technologies is to matrix extra surround information into two sound channels, so that it can be output with conventional stereo equipment. A proper receiver that can decode this matrixed surround information can then place the sounds in the right spots.
However, I don't see how it can possibly be as good as having discrete channels like AC-3/Dolby Digital. I'd think there would be too much chance of bleed/crossfeed and general signal degradation. Basically, if the system can do Dolby Digital to begin with, there isn't much point in doing Pro Logic since there's no need to compress 6 channels into just 2 and expand them back into 6 when they could keep all 6 discrete from the start.
Given the way Dolby Labs pitches Pro Logic IIz on their site, though, I'm not even sure anymore...I really don't like it when companies give very different features similar names. (Creative's just as guilty with "CMSS-3D" potentially referring to three completely different features, depending on speaker setting...two of them kind of overlap, but one's meant for headphones and the other's meant for stereo speakers. The third's simply a stereo upmix to play the same sounds in the rear channels, seemingly like what the original Pro Logic was designed to do.)