have Sound Blaster Audigy 2 ZS
from that 1 2 channel 900w amp for subs,and one gto 600w 4 channel amp for front and rear speakers.when i test with creative speaker tester in 5.1 all speakers have sound but when i play audio on pc only fronts on,its if there is only 1 line working.tryed all settings 4 channel amp,sound coming from front no rear but db lights on amp are moving so its getting something from sound card,cant tell with sub as theres no lights.