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intended primarily for the left and right screen loudspeakers are fed to the left and right channels. Program
material intended for the center screen loudspeaker, including most on-screen dialog, is fed to both stereo
channels in phase. The in-phase relationship between the stereo channels triggers the playback matrix to steer
that information primarily to the center screen loudspeaker, through a combination of gain control and altering of
separation coefficients within the matrix. In a similar manner, information intended for the surround channels is fed
to both stereo channels so that there is a 180° phase relationship between them. This phase relationship triggers
the playback matrix to steer that information primarily to the surround loudspeaker array. Figure 2B shows details
of the playback matrix used for the Dolby Stereo Optical format.
Figure 1: Magnetic film formats. 70-mm (A); 35-mm (B)
Figure 2: Dolby Stereo Optical format. 35-mm Dolby SR format (A); playback matrix (B)
