Totem Winds are Too Bright

I'm trying to figure out why my Winds are always too bright. I'm not getting the bass balance I want, which in this case would be more bass. Could it be that having a copper connector to connect the biwire posts on the speakers could cause this (not seperate bi-wired cabled)? Could it be that powering with a 45 watt/channel tube amp might not be giving enough power to adequatly run the full sound stage?

Your thoughts please.