HDTV Forum

Dolby Pro Logic is a stereo analog audio compression format used in the early days of home theater applications providing 4 main channels and is still used today for television. With a stereo system you get great stereo sound and with a decoder you get the additional center and rear surround channels. While not providing a separate subwoofer channel most decoders had a cross over for the sub and mains creating a 4.1 system. This system also worked with non encoded stereo sources as well. With mono sources only the center channel will have sound.

See Sound Fields