Thanks for the reply and thoughts, much appreciated and I will investigate.
I ended up returning the RB 61's just today. Hated to let them go, but the highs often literally hurt my ears. Piercing. I had to back off the treble for most music. I played mostly records using a Yamaha RX300u receiver. On the plus side, the base was more solid as they broke in.
Yes, indeed, they were used in a room with a laminate wood flooring over concrete with a thin foam vapor barrier first placed over the concrete. Room is about 15' x 25' with very high ceilings. Perhaps it intensified the highs as you say. As a note, I put them in a carpeted living room test for movies and indeed the highs not nearly as intense.
Thanks again.