If you're replacing speakers in the Advent cabinets i would have a suggestion "if' the speakers you purchased have a funny looking tweeter LEAVE IT! its possibly a "fried egg tweeter' that the Advent creator mr. Henry Kloss designed, the Advents i have are stamped and signed by Kloss as being manufactured on 6/74 if i recall correctly ,those tweeters are invaluable to us modern day Adventors