Yeah I am a minority, I'm one of the few smart ones that realises 16bit stereo 44khz sounds identical coming out of the k7s5a as it does a 100$ sound blaster. Maybe some high end turtle beach cards might have better quality components such as filters / caps and resistors that could be noticed on a 3000$ home theatre setup, but if you're going to set it up on a measley* klipsch promedia setup then you're kiddding yourself if you think there's any difference.
I would like to know what experience you base your claims on. Have you actually listened to the onboard sound of a K7S5A, and then a good sound card? The sound quality of some onboard solutions can be quite good - If you had said the quality between a C-Media 8738 onboard and a SB Live was indistinguishable on mid range PC speakers I could have believed you. But the SiS 7012 is particularily poor.think onboard sound being "bad" is just a claim of jelous tech-heads who spent 50-300$ on their hardware (that was well reviewed by another tech-head) who can't deal with the fact that $5 worth of IC's makes a good enough sound reproduction that humans can't distinguish it from their fancy stuff.
Toshiba onboard waveform
M-Audio Sonica waveform <- Makes real high end sound cards
My main complaint about the 7012 is the lack of clarity in the bass, which appears to be similar to the situation on the Toshiba. Are you saying that it is impossible for the human ear to detect the differences that significant, that are being picked up by computer measurements? Finally, what audio expertise do you have to be able to say I don't know a damn thing about it anyway?
*, klipsch pro-media speakers are DEFINATELY measley compared to a TRUE audio setup, they might be very high end for PC speakers, but they are no where near top end audio.