pahcman said:DD5.1 rocks.
Soundstorm rocks Xbox (and PC).
Like someone said, MS over engineered Xbox.
Let hope Sony can get DICE license and Nvidia put Soundstorm2 into PS3 and not SPU3..
DD 5.1 is okay. But as being lossy, no use of using it in multichannel recordings that have high dynamic range in all channels. the bitrates aren't enough. (72 men symphony orchestra recording from the middle of the instruments, for example.)
and what comes to Dolby Pro Logic 2, it is doward compliant with DPL 1 and the oldest Dolby's surround systems: Dolby Surround. Last one is already more than 20 years old and with Pro Logic, it was pretty much standard even in theathers, before discrete digital channels replaced the old "optical sound" used all way near to begining of movies with audio track.
Surround / Pro Logic / Pr Logic 2 ain't bad, as long as you have correctly set up speakers. (In Surround: 3 speakers (Left, Right, Effect/Rear). In Pro Logic: 4 speakers (Left, Right, Effect and Center). In Pro Logic 2: 5 Speakers (Left, Right, Effect Left, Effect Right and Center). LFE (Low Frequency Effect) is done in all with Low pass filter from combination of two input channels.
Latest add-on to this series is DPL 2 EX, which adds both side speakers, which basically should expand the sound even more. I haven't yet tested this though.
In any case, Dolby Surround was originally planned to be a way to encode 3 channels to 2 analog channels. of course because this is done with Signal Processing (directing certain kind of parts of signal on different speakers) it can't be as exact as using discrete channels. Nowadays, when using discrete channels is become possible (thanks highre compression algorithms and more powerful and cheaper processing units) Pro Logic has been a become way to expand audio fields from sources that were originally just planned to be 2 channels or even mono. (anyone remembers Dolby Stereo?) And that why Dolby has continued developing also this older standard.