Dolby Pro Logic was introduced shortly after for playback of the center channel as well. Pro Logic II added left and right surround channels (5.1), and Pro Logic IIx added support for 6.1 and 7.1 ...

Dolby has been associated with surround sound equipment since the introduction of its Pro Logic technology in 1982, which at ...

it can provide powerful sound with surround sound decoders including Dolby Pro Logic II, Dolby Digital, Dolby Vision, Dolby Dual Mono, DTS 96/24, DTS decoder, Dolby TrueHD and dts HD Enhanced ...

The Dolby Pro Logic IIx high-definition audio technology will be made available for PCs, and a new Dolby PC Logo program will be provided to system builders developing products based on Dolby's specs.