I currently have a RB-81II for the center speaker and feel it just isn't keeping up with the rest of the system and it sounds a bit "boxy". So, I was kicking around the idea of trying (2) RB-61II's (Stacked vertically) that I have lying around. I do have a couple of open amplification channels on my UPA-700 that supplies the ceiling speakers to use for both 61's.
Or, would a entirely different center speaker be considered? If so, please give me your recommendations.