Hi sushi,
A modest correction: in a movie playback, the dialogue is routed to the center channel, and because our ears are particularly sensitive to midrange sounds, where human voices reside, we are very alert to tiny tonal variations between the left and right front speakers and the center.
That said, the center is NOT the most important speaker in a home theater system (all are important). It is certainly the one subject to the most timbral variations because of its inevitable awkward placement on top or beneath a TV, but a great deal of musical content, effects, and off-screen dialog is carried by the main left and right as well as the surrounds. Moreover, it is the left and right front and two surrounds that supply the stereo and 3-dimensional soundstage that provides all the realism of home theater playback.
Regards,
