yes but it depened on the speakers with my tests, my altec lansing ones did not like you increasing the windows mixer stuff at all becuase it could crackle quicklier. and no, for me, ive done wave at like 80% before and i think its worse because the guns arent as loud, and no it didnt add distortion, infact it like had less and it was more fun, but on the altec lansings i had anyhting above 75% wave crackled. while maybe the bass setting at 70% (can) screw it up, but its very rare, liek in guildwars for example, bass at 70% maybe distort the (some) of the music, not in a cracklier way, but just mufflied, but the combat is so much better tho. but 60% did not result in real distotion in guildwars, but 70% seemed to me to be better for everything else. while i do disable the 24-bit crystalizer, id rather increase the bass then have some phoney 24 bit thing that makes sounds annoying be on. DO NOT HAVE MASTER VOLUME ABOVE 80% on x-530, do NOTT, unless its a dvd movie, its GOOD to have it at 100%, trust me ive tried, anything below 100% for movies is too low, and it doesnt add distortion, but in games u must rely on wave which could screw trhings up for you, but have that at 100% for this case.
and oh yah, for games keep treble at 50%, and for movies i guess 55% is fine.