Crazy people; often, but not always, musicians; who have a good enough ear to distinguish the differences between various calibers of audio equipment. Of course, because they can distinguish these differences, they automatically have to have the best system they can possibly afford. Not to impress the neighbors, as some rich pricks might think, but for sheer aesthetic pleasure. More often than not, it only impresses upon the neighbors just how damned loud your system can get. The pinnacle of audiophileness is the THX sound system, which has been known to induce large amounts of drool in audiophiles. They often experience moments of aural bliss.