I have the same problem, I have a 5.1 speaker system creative a520 which has three 3.5mm jack, the worse part is wala syang RCA pang pc Lang cguro ito, alam ko meron adapter na three 3.5mm to RCA kaso wala ako makita puro sa Internet Lang, meron din optical port yung xbox ko and pwede ko say I hook up via RCA, problem ko Lang talaga is to convert the three 3.5pm jack to RCA or optical . Baka meron kaung idea mga masters. Thanks in advance