Due to room constraints (of an entryway) and an unually high ceiling, my QS8s are 9 feet off the ground and they sound great. Think movie theaters...they have their surrounds quite a bit higher than 6 feet. I think they'll do a great job for you at just about any height. But if you have a buddy that's willing to hold one for you and move it around while you sit in the sweet spot to see what sounds best...then kudos!

"We're on the island of Misfit Toys"