i think you have the same problem i did. i have a set of klipsch 2.1s that were fantastic, but then for some reason started playing a fair amount of static and i just figured they were blown which sucks seeing as they were 150$ speakers. it was tolerable so i just used them like that for the next 3 years..
recently i got a used mobo/processor and an audigy sound card form my friend. i just put the stuff together and wow... all of a sudden everything sounded crystal clear again.
so imo its your sound card and audigy FTW!