Heyyo,
Ah, so it has a built in amp? then it should be fine man. Like freak said, just get an adapter that'll do 1/4th female to 1/8th male/female. If you can get the one that goes to 1/8th female, that way you can just run a 1/8th male both ends cable from the adpater to your computer which will help to not crowd the back of your computer. I used to use a stereo 2 female RCA plugs to single 18th male adapter for my speakers but they had no amp so that sucked. So I just bought some random half-decent amp, and then I was pleased as the volume was loud.
heh, your miniplug thing confused me for a sec, never heard that term, I'm used to 1/8th jack or plug.