Dolby Pro Logic II Movie / Pro Logic II Music. Despite its success, Dolby Pro Logic never really "worked" quite right on music, or more specifically, material which was not specifically "encoded" for matrix playback. Dolby Pro Logic II uses advanced Matrix technology to improve on the original in several ways. It derives 5 channels from the 2 channel carrier (Left / Center / Right / LeftSurround / RightSurround). It includes "Music" and "Movie" modes which cater to their namesake's material, Movie being more center channel concentrated versus Music which is more expansive and "works" on non-surround encoded material.
DTS Neo:6 Cinema / DTS Neo:6 Music. This is DTS's effort at a Matrix system which takes two-channel source material and delivers up to six channels at playback: Left / Center / Right / LeftSurround / CenterSurround / RightSurround. The "Cinema" vs. "Music" variations cater to their namesake's material, with Cinema being more center channel concentrated versus Music which is more expansive.
Dolby Pro Logic IIx. There are actually two parts to Pro Logic IIx. The first is its role as a classic Matrix decoder. It distinguishes itself by delivering up to seven channels (as compared to Pro Logic II's five, or Pro Logic's four). Like Pro Logic II, it includes Music and Movie modes. Note that both the side channels and rear channels are stereo.
Pro Logic IIx also plays a role with Discrete 5.1 material by deriving four surround channels, as oppose to EX's three, yielding up to seven main channels. It includes Music and Movie modes. Although, like THX Ultra2, it is designed to accommodate non-EX encoded material, Dolby recommends the Movie mode for all movie material, including EX encoded soundtracks.
