Tweeter height and listening height depends on design choice and owners set up. For most loudspeakers best is ear between mid and tweeter, or mid centered on ear with tweeter above,slightly back from mid. No one listening height works for every loudspeaker. If yours sounds best with tweeter aimed at ear or set up with tweeter at ear level great. Many loudspeakers are not designed to perfrom optimally set up so.
Tweeter height
I picked up a pair of Ushers that are 50" tall and was wondering what the deal is with the tweeter being so high, it's mounted at the top. I always thought the ideal tweeter height was at ear level. They sound great, but am curious about how some speakers are designed with the tweeter so high.