My hunch would be the following:
o If the B&W 805's are monitors, you're already looking at an unbalanced or presentation weighted toward the highs. Consider either a set of full-range speakers and/or adding a subwoofer. Addressing this area could be a signifanct contribution to correcting your problem.
o Don't underestimate the significant contributions properly located speakers can make.
o Experiment with other line conditioners, ics, and speaker cables.
o Try removing all hard-surfaced furnishings and wall decorations from the room including leather chairs/sofas, end-tables, lamps, pictures, etc.
The list is near endless. But addressing one or more of the above could provide startling improvements.
-IMO