What Randy described is the best way to do it -- use a sound card which can feed digital audio directly into your receiver via the coax or optical connections.

Next best is to pick up a cheap used stereo receiver or integrated amplifier and get a cable which goes from one of your SB "speaker" jacks to the Aux inputs on the receiver/amp, then hook the M2/M3's up to the speaker outputs of the receiver/amp.


M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8