the "ball" is the dome of the tweeter, they are dome tweeters. unlike cones, but there are cone tweeters as well on the market. theyre just really cheap junk for the most part. the tweeter in the axioms is like a woofer, but just think of it like the dust cap covers the whole cone. I dont know exactly what your talking about when you took the klipsch apart. but it sounds like you might be talking about the voice coils when you say the wire.
And yes the tweeter vibrates, if it didnt, it wouldnt make any sound. i have torn apart woofers (out of a tv) and i know how they work, but i havent ever torn apart a tweet but id imagine its basically the same. if you go to the dynaudio website they have cut in half drivers that will illustarte it for you. you have to watch the video that is playning at the top of the page
HERE 
