Extracts four audio channels from a specially encoded two-channel source:
Two channels for speakers at the front—left (L) and right (R).
One channel for speaker at the center—center (C).
One channel for both surround speakers at the rear—mono surround channel (S).
Describes the Dolby Pro Logic matrixed surround system. Source media, usually VHS, Laser Disc, television broadcast or CableTV/Satellite is often branded with "Dolby Surround" logo. This is the encoding used on the analog optical track for theatrical motion picture films.
Placement: (Five speakers in total) The front speakers should be placed at the edges of the screen, toed in to face the central listening location, and the tweeters should be ear height. The center speaker should be placed behind the screen (when using projection) or over or under a TV, and as close to ear-high as possible. Surround channel speakers should be placed above ear height, slightly behind the listening position, and should be of bi-pole construction.
