I set them about 2' from the floor (my ceilings are only 9').
As for impressions, before the bass traps, it always felt as if the bass in my room was drift toward the stairs and staying trapped in there. Basically, I sounded like the best place for bass response in my room was the stairs. Not an ideal spot was Home Theater and Music enjoyment. When I installed the corner traps, I could hear the sub better from my original listening position. The overall sound was definately enriched due to the better bass response. Definately worth the time, effort, and cost.
