Double stereo, single set of speakers...

ok, i wanna build up a computer based kit to store my music, play it through MP3 so forth and so on, and meanwhile, and a HU. anyways, would i be able to do this with only 1 set of speakers? currently, i'm running 4 speakers *2 front, 2 rear* straight from a HU... i wanna put in 2 amps, forward and back, powered by a USB SoundBlaster card *takes digital sound from computer and outputs on the standard LR cable used between most HU and amps* and run wires from the amps to these speakers... however, i'm worried that it'll feed back up into the HU effectively destroying it. needless to say, i can't experiment with it, wondering if people had ideas. ~~Dan

if your HU has any kind of input you can take the out from the PC and put it to the HU and control volume from there also. Also check www.mp3car.com if you haven't already