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.
Good topic. According to Robert Harley in his book, The Complete Guide to High End Audio:

"Typically, the loudspeaker will be brightest (i.e. have the most treble) when your ears are at the same height as the tweeters or on the tweeter axis. Most tweeters are positioned between 32" and 40" from the floor to coincide with typical listening heights........The degree to which the sound changes with height varies greatly with the loudspeaker. Some models have a broad range over which little change is audible; others can exhibit large tonal changes when you merely straighten your back when listening...."

So in general, your tweeters and your ears should be at the same height. You may need to invest in a chair with a high adjustable seat or perhaps a chair like a bar stool. You may want to check to see if your Ushers fit the category Robert describes where little change is observed when listening height changes (broad range). You could also tilt them in towards you and toe them in as well. Experimentation is a must but also check with Usher to get their recommendations. Did the speakers come with an owner's manual with recommendations?

Let us know how you do. I'm sure many folks would be interested.
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.
I've always liked monitor speakers that you can put on stands, and in turn play with the height, tweaking it until you get the best sound for your ears and room. I have ProAc's, both floor standing and monitor. The 1sc's, with a sub, edge out the floor stander, 140's. I also have a center channel 140 and have found that playing with the height via a completely adjustable height stand, has given me a better sound, once tweaked. I am currently looking for a pair of 1sc's to see what potential they have for being a center channel.
Proper tweeter height on some speakers can make an amazing difference. I was using a pair of Silverline Audio SR-11s on a pair of 24 inch stands and they were sounding nice enough but I noticed if I slumped down to a point where my ears were at the midway point between the tweeter and woofer they were completely different. The soundstage became deeper and wider with wonderful images floating in the music. Needless to say I got taller stands. It really can make a difference.
Better the tweeters are too high than too low. But ear height, from all I've been told, is the proper tweeter height.