How tall should speakers be?

HF driver should be at about ear height for conventional dynamic speakers.

Kal

If you speakers sound better when your on floor then place something under front to pitch the tweeter up tp your ear at listening seat. As Kal said in general tho not always true the tweeter is most important to have around ear level.

Some speakers have a critcal vertical listening window. I owned a set of Spica TC-60s ten or so years ago and tweeter response was radically different if you were standing or sitting. The difference was even audible at about +/- 5 degrees. So, yeah, where your ears are verically in relation to the tweeteer is very important with some speakers.