The rule of thumb for high the TV should be is that your line of sight should line up with the center of the screen when seated. If you look at the height of TV stands that are made by the same manufacturer of the TV you'll find that those stands are between 18" and 20" tall.
Mine is 24" tall and seems fine, but 46" is rather tall and you might find that tiring as you will essentially be tilting your head up to view the TV.