i have creative t6100 speakers with on board realtek hd sound but wanna upgrade my sound card which is best for my speakers hows xfi titanium or xfi surround 5.1 usb for it .my speakers r compatible with new sound cards.
you can try any cheap 8738 card for 10 dollars (I own one in my kitchen's PC), those have a nice bass and no disturbing treble. if you want more quality Xonar DG looks a good companion with those speakers.
Personally, I had a Creative X-Fi XtremeGamer... I could tell a big difference between my onboard and the soundcard. In games, footsteps were much clearer and I could tell directionally where they come from. Music sounded much clearer and I was able to raise my volume exceptionally more, at 50% sound it was blasting.. when I must have my onboard at 100%.