and the system can then play sound out of just one of those seven speakers if it wanted to? So, in playing games (we can take DoomIII for example) you can hear a monster behind you and pinpoint its location and know what direction it is in better if you had 7.1 sound versus a dinky 2.1 sound?
The game also has to be programmed to support this. I only know of EAX Advanced HD2 that takes advantage of all 8 channels. Older tech may only support 7 or 6 channels. Most games, if can take advantage of the rear channels, can only produce a mono signal for those two rear channels. It is rare to find a game that can produce two discrete signals for the two rear channels.