Equalizers anyone?

The Rives is a very different product from the Accuphase which in turn is very different than the Cello. Each is a good product, but they are optimized to accomplish different tasks. You'd get better responses if you stated what type of room deficiencies you're trying to address.

If used properly a parametric EQ can be very effective at smoothing out bass response. They'll work best with those speakers/rooms that need it least.