[jujumantb]

think of the red and white component cables coming out of your xbox as the mini-jack on most computer sound cards. In fact, you can buy adaptors to convert the mini-jack to RCA's...
[img]http://images.techcables.com/yf.jpg[/img]
They are the same thing, just in a different casing (RCA or mini-jack).
So if you think of it like that, now think of how you would hook speakers up to your PC. Same thing, you could, of course, even buy "PC" speakers and use them with your xbox with the right adapter. (if the PC speakers dont take an RCA input, but a mini-jack instead)