I currently have the promedia 2.1 system. I was looking into getting promedia 4.1 system as well, to try to make a 5.2 speaker system to hook up to my HTPC. Has anyone tried to modify their promedia 2.1s so that it can work hooked up to the center/sub output on their computer? Is there an easy cabling fix? If i am able to isolate the center channel with some creative cabling, would this make my sub useless? What about if i took the center/sub out and used a stereo to mono adapter and then used a mono to stereo adapter again so that i would have 2 channels with both the bass and center channel audio, would the crossover in the sub then send the correct center channel audio to the 2 satellites, and the bass to the sub? Suggestions?