Why am I experiencing listener's fatigue?

Buyers remorse. You are thinking about all the fun you could be having if you had spent money differently.

Buy a Bose and a motorcycle.

Anything in-between speakers? Throw a blanket over it.

you have a great system. but sometimes different is better.

The Monster Power will not cause fatigue, thats a stupid statement, so many people here throw Monster comments around like BOSE, and most have never had any real experience with it.....just stupid

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