Surround sound means just what it says, sound that surrounds you. Surround sound is supposed to make you feel that the sounds you would hear in what you see on the screen are coming at you in the same way as they would in a movie theater. To achieve this goal, different types of surround sound systems have been created with special speaker placement, these systems are summarized below.
2.1 channel surround sound systems. This system is the most basic and includes a two speaker minimum.
3.1 channel surround sound systems. This system is the same as 2.1 but with an added base channel for a subwoofer. In both systems the two other speakers would be placed in the left and right center of the listening area.
5.1 surround sound speaker systems. This systems uses five speaker and a subwoofer. Three of the speakers are used for the front left and right and center speakers and the remaining two speaker are placed on the sides of the theater or room. These side speakers are designed to project the actual surround sound, sounds that heard from the left and right planes of the listening area.
7.1 surround sound speaker systems. This system extends the 5.1 system by adding another two speakers to be placed behind the listening area, these speakers are meant to imitate the noises heard from behind.