Hmm it all depends on exactly what you wanna do with it, the 5.1 speaker system I got has a button on it that will take either a stereo or 5.1 source and output it as 5.1 works too, not bad effect either, I can control the volume of front / rear / centre & subwoofer and overall it was a cheapish Trust 5.1 kit, but it does the job takes the speaker output from my PC and amps it up nice
What can I say it does me, don't need 25W/chan speakers etc and I honestly don't see the point in having huge speaker, okay I can see the point of the "higher powered" ones as they will be able to take more power and give more volume - all fine and well if ya wanna go deaf quick, I don't..
Hmm I know i've went Off Topic but hope that helps / explains a bit