(I'm posting this for any lurkers who might actually be taking the good advice offered here to heart)
I know jiminy about sound cards so I'll just show my intelligence by saying nothing.
True, but you need adequate power to get the best out of any speaker. I got to play with those Pioneers 41's at Best Buy. They are great: clean, detailed and everything I would want for a satellite speaker, but they are only 4" drivers and are quite inefficient.
Keep in mind Hoffman's Iron Law of speaker design: Small size, good efficiency. Pick two, any two.
True, if the mains can go down to a reasonably low enough frequency to be musically satisfying. Remember, the Pioneers are only 4" drivers.
And, I have those Dayton 652's. Flat and uninvolving. They are sitting in my basement, unused. Five or six of 'em with a subwoofer would be a good starter HT set but, for music, well, I'd take the little Pioneers with power any day. ...but, while they will be satisfying in a musicsl, well balanced way, you'll really want a subwoofer to fill in the bottom octaves pretty quickly.