The ability to provide 5.1 sound had been one of the key reasons for using 70 mm for prestige screenings. When digital sound was applied to 35 mm release prints, with Batman Returns in 1992, the 5.1 layout was adopted. Instead of the five screen channels and one surround channel of the Todd-AO format, Dolby Stereo 70 mm Six Track provided three screen channels, two high-passed surround channels and a low-frequency surround channel monophonically blended with the two surround channels. Dolby first used split surrounds with 70 mm film, notably in 1979 with Apocalypse Now. 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. ĥ.1 dates back to 1976, when Dolby Labs modified the track usage of the six analogue magnetic soundtracks on Todd-AO 70 mm film prints. Īll 5.1 systems use the same speaker channels and configuration, having a front left and right, a center channel, two surround channels (left and right) and the low-frequency effects channel designed for a subwoofer.Ī prototype for five-channel surround sound, then dubbed 'quintaphonic sound', was used in the 1975 film Tommy. 5.1 is also the standard surround sound audio component of digital broadcast and music. Dolby Digital, Dolby Pro Logic II, DTS, SDDS, and THX are all common 5.1 systems.

It uses five full bandwidth channels and one low-frequency effects channel (the 'point one').

5.1 is the most commonly used layout in home theatres. The left and right surround speakers in the bottom line create the surround sound effect.ĥ.1 surround sound ('five-point one') is the common name for surround sound audio systems. 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 center speaker in the top line of the diagram is used for dialogue. The white square in the center of the diagram depicts the low-frequency speaker. Most common loudspeaker configuration for 5.1 used by Dolby Digital, SDDS, DTS, THX, and Dolby Pro Logic II.

Tracks 5 one