Understanding Surround Sound Systems
Surround sound is the concept of expanding the spatial imaging of audio playback from 1 dimension (mono/Left-Right) to two or three dimensions. It is often employed for a more realistic audio environment, actively implemented in cinema sound systems, technical theatre, home entertainment, video arcades, computer gaming, and a growing number of other applications. Many popular surround sound formats have evolved over the years. They include ambisonics, quadraphonic, Dolby 5.1 Surround sound, DTS, and MP3 Surround.

Surround Sound Philosophy 101
There has been a long evolution in commercial movie theater sound. During the first two and a half decades of movie theater presentations, a piano, organ, orchestra, sound effects man, or actors reading the dialog comprised the sound of movies. Electronic sound appeared in 1926 with the coming of the "talkies." Theaters were wired for sound, and a big speaker perhaps set behind the center of the screen did it all.