Dolby Pro-Logic II
This is one of many surround sounds created by Dolby Laboratories (AKA: Dolby Labs; Dolby). Officially the surround sound that really started it all for having a home theatre, Dolby Pro-Logic, is no longer even mentioned on Dolby’s official site at the time of this posting.
For info on the original Dolby Pro-Logic read my post titled “Dolby Pro-Logic Revisited.“
Later on Dolby made variants of Pro-Logic with three formats; Pro Logic II, IIz and IIx. This post will explain the differences between them.
According to Dolby:
“Dolby Pro Logic II transforms traditional stereo audio into 5.1-channel surround sound for a seamless listening experience full of presence and depth.”
This above quote and more about this format can be found here on Dolby’s official website.
Pro Logic IIz adds more depth to the sound heard.
Pro Logic IIx adds listening modes to further customize how you hear everything.