i get the gist of what your talking about..
the stereo recievers you have hooked up to your computer are off a y output from your sound card, halving the signal. you can't really amp just that. and your stereo recievers are just amping the signal to the speakers. i'd just leave it how it is. if you have a soundcard that has a front output and a rear output, use one output for each stereo reciever. most soundcards like that have software that allows "processing" to the rear channel or you can set it to straight clone outputs.
let me know if this makes sense, i can explain it better once i wake up somemore!
i've got my computer hooked up to my pioneer mixer and KRK studio monitors, it sounds so nice!
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I've never seen a supernova blow up, but if it's anything like my old chevy nova it'll light up the night sky!