[yage]

I was of the opinion that upsampling involved the stuffing of bits in the original signal:

Multirate Interpolation FAQ

As it says in the FAQ, filtering takes out the unwanted spectral images theoretically leaving the original signal intact...

 

[ppl]

Well the Reason i brought this thred up is I replaced the SB Live with the Audigy and noticed a slight improvement in the upper mid's and highs. I consider myself a Music lover more so than an Audiophile but the Love of Music brings me and the High end Closer together. Maby ill check out some of the Cards listed.