Well, the plug on your speakers appears to be a 3.5mm jack. This is the same jack used by about 80% of speakers and headphones for computers, Cd players, etc. You can buy cables that convert the 3.5mm jack to two (left and right speaker ( RCA / component ) jacks, but I am not sure if you can get any that have a female end for the RCA jack.
It looks like what you'll want is a 3.5mm female to RCA female connector, though they don't seem to exist, or at least are not common. You may need to get a 3.5mm male to RCA female and then buy a male-female converter to stick on the end of the 3.5
I'm trying to connect my Xbox 360 to a set of computer speakers, plainly. I'm using the VGA adapter, so that aspect of the connection corresponding with my monitor is in. Since it lacks speakers, I'm left with using a speaker set. This speaker set has only a single cable, ended with a plug, that is green. A single audio input... and yet my 360 has dual audio inputs - Not to mention that you can't plug two... plugs... together. What sort of adapter would I need to make these two correspond?

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