Typically, you connect the Xbox 360 gaming system audio output to the television you are connecting the device to. However, if you want portable speakers and possibly a surround sound system without throwing down a few hundred dollars, you can actually connect the Xbox 360 to computer speakers. Computer speakers are typically less expensive than home entertainment speakers, and you can transport the speakers to other locations.
Plug the provided RCA cables into the "Video Out" port on the rear of the Xbox 360 (the Xbox 360 has a single RCA out connection marked "Video Out"). You do not need to use the yellow video connection with your television if you are already connecting the through a different video method (such as HDMI or component).
Connect the red and white RCA audio cables into the RCA to 3.5mm "Y" splitter cable. You can find this cable at most electronics stores.
Plug the 3.5mm cable running out of the computer speaker system into the 3.5mm end of the splitter cable.
Plug the computer speakers into a nearby electrical socket and power the speakers on. You can now hear all of the Xbox 360 audio through the computer speakers.