What causes listener fatique? cure?

What is your current set-up?

I think most speakers in that price range will spare you the drilling highs. In my experience the culpret is usually the electronics. I'm sure there are speakers, however that are more forgiving of bright electronics. Magnepan and Ruark come to mind, so do tubes, turntables and the Ikemi cdp.

Yes, generally its grain, grittiness, forward high frequencies, as you say. But personally I also find, that anything in your setup, which keeps you from being drawn into the music, so that you are consciously or unconsciously forced to listen to your system instead of the music is eventually very fatiguing.
As far as speakers are concerned, I think we should know your setup and which kind of music you prefer.
Regards

Ohala beat me to it,tubes, in triode, if everything else is good = m&m (music & magic).

Sorry about the user name error Ohlala. Oh,and a 14 hr day of breaking rocks wouldn't help either.Cure for that? A city, state, or fedral job : where you only have to "lean" on the shovel.