When I got my speakers hooked up in my new room, they seemed somewhat flat. I didn't think that it was the speakers or electronics, but that my personal taste is for more punch (using a "V" shaped EQ curve in my car, or other systems I listen to). The room being set up properly just meant that I was getting probably a nice flat response from the Axioms, and not a "hot" room impacting it.
You might be experiencing a flatter response from the speakers that you didn't get previously. Sorry, wish I had more ideas.
M60s, VP180, VP150, QS8s, M3s, SVS 20-39PCi, Shakers