The voice coils are on the bottom, pointing upward. The tops are fixed. When sound is applied, the voice coils move (literally) up and down, which squeezes the "leaves", forcing them to move inwards and outwards. There are 12 of them for each driver.
Read the bottom half of this page.
Yeah, if I ever win the lottery, the first thing I do (after moving to a new abode) is to get a pair of MBL's. Not sure which ones, though. Probably either the 101's or the 111's.