output to all speakers means,
1) Standard - two speakers, then send audio to both speakers.
2) 2.1 speakers - 2 speakers and a sub-woofer then output audio to all 3.
3) 5.1 speakers - 4 speakers, 1 center speaker and 1 sub-woofer, then output audio to all 6.
In order for the six channel option to have the best effect, you need 5.1 speakers hooked up to your xbox, which requires the xbox digital audio package or the like.
6 channel audio is the same as surround sound, try to think of each speaker having 1 channel:
Surround Sound setup each square represents a speaker and you are the circle in the middle.
Note: you are surrounded by sound, thus surround sound.
FR = Front Right Speaker uses channel 1
FC = Front Center Speaker uses channel 3
FL = Front Left Speaker uses channel 2
RR = Rear Right speakers uses channel 4
RL = Rear Left Speaker uses channel 5
Sub-Woofer uses channel 6
If my thinking is wrong someone please correct me.
Note: Put the sub-woofer somewhere near the floor for best effect
also in any speaker package, the sub-woofer is alway noted by the .1, as in 5.1 means 5 speakers and a sub-woofer or 2.1, which means 2 speakers and a sub-woofer.