I havn't heard any snap crackle popping yet. I had a similar issue as well with my XtremeMusic. If my Master Volume was set too high, I got very bad staticy sounds. My solution was to lower Master Volume to about 45%, but occasionally I would still get crackling/popping (it almost sounds like its clipping) in some games including the Bioshock demo at times where the volume would increase a lot (like during a scripted event).

Happy to say I have not come across any of these issues with the Prelude yet. I've left the Master Volume at 50%. No sound artifacts in Bioshock either