I have an altec lansing powered subwoofer (built in amp) for i believe a surround sound for computer, could be for other surround sound too. I cannot figure out what cord/adapter i need to hook it up. I know i need a cord with the rca audio cable to hook up to my xbox or dvd player audio plugs. But i cant find a cord with the other end to connect to the subwoofer. The sub has just one hole/connection plug. It is not a plug that audio cables could fit in to. Please try to help me! THANKS!! HELP IS APPRECIATED!!