Why am I experiencing listener's fatigue?


My system is as follows. All thoughts and opinions are welcomed and appreciated.

B&w nautilus 805 speakers with jumpers ,
tweeter/driver grilles removed/tweeters at ear height
Cardas cross single wire speaker cables
Cardas golden reference interconnect
cardas golden power cord
Monster hts 2000 power bar/conditioner
Manley stingray (2 mullard 12at7's and 8 Ei el84's)
sony xa 777es cd/sacd player
7 inch diameter by 18 inches high concrete speaker
stands
blu tac between the speakers and stands
Particle board equipment stand
14 inch (1/4 filled)innertube under the sony
No DIY or professional room treatments at the moment
Stock sony power cord
vertigo
Vertigo, also consider auditionning Sonus Faber Cremona, Cremona Audior and Vienna Acoustics Strauss. I audiotioned these and thought they were pretty nice but a little too smooth sounding for me. I like a little more open sound, but if you experienced fatigue with the N805s, these may be the ticket for you, depending on how much you want to spend.
And I would also suggest that when you audiotion the speakers in the showroom, make them play that system as loud as you would listen to your system at home for at least 30 minutes. This way you could tell if the speakers make you sick.
You could find some usefull info on the speakers I mentioned here - http://www.sumikoaudio.net/

Best of luck to you.