5.1 surround sound

[6] 5.1 dates back to 1976,[7] when Dolby Labs modified the track usage of the six analogue magnetic soundtracks on Todd-AO 70 mm film prints.

The Dolby application of optical matrix encoding in 1976 (released on the film Logan's Run) did not use split surrounds, and thus was not 5.1.

A system of digital 5.1 surround sound was also used in 1987 at the Parisian cabaret the Moulin Rouge, created by French engineer Dominique Bertrand.

The same engineer had already developed a similar 3.1 system in 1973, for use at the official International Summit of Francophone States in Dakar.

[9] In music, the main goal of 5.1 surround sound is a proper localization and equability of all acoustic sources for a center-positioned audience.

Most common loudspeaker configuration for 5.1; used by Dolby Digital , SDDS , DTS , THX , and Dolby Pro Logic II . The white square in the center of the diagram depicts the low-frequency speaker. Each black square depicts a loudspeaker. The center speaker in the top line of the diagram is used for dialogue. The left and right speakers on either side of the center speaker are used to create stereo sound for music and other sound effects in the film. The left and right surround speakers in the bottom line create the surround sound effect.
Suggested configuration for 5.1 music listening