Listening fatigue

The sound travel 1000 feet per second. You can hear the sound from speakers for 4th of a second and the sound will travel 250 feet. Your room is 15 x 20. Every sounds from speakers will bounce walls and hit your ears more than 10 times. That's no good! I don’t know if your room is sonically live or dead. If it’s live, you need to tame your room. You need to reduce the sound reflection.

I recommend 1) Madisound Dampers: Felt Defraction Ring for Tweeters. Put these $2/each felt ring on tweeters of Mites. These dampers will reduce some early reflection sound from speaker cabinets. 2) If the room is live, put some Auralex or sound absorbers on walls. If possible put some damper on the ceiling too. If your wife think they are ugly, put some pretty curtains on walls instead. Good luck!

If you get rid of early reflections, some imaging information will seem to be lost. This is because the ear/brain system uses early reflections to assist in image location.

I would test if reducing early reflections work. I would make a couple of 5” or 6” diameter thick paper rings with 1.5” hole in the center. And attach them on tweeters using double side tape. Also, put towels on the top and side of speaker to stop resonance from cabinets.

Ditto the early reflections. Added bonus: by minimizing early reflections later reflections are minimized geometrically. Minimizing corner reflections and slap echo is also important. But I would avoid Sonex like the plague.

Listening fatigue can be either the result of too much
volume overwhelming the sensitivity of your ears, or there
may be components within the stereo system that just don't
work well with the overall system. For me the biggest culprit has been my choice of speakers. Heavy and very tall tower speakers by their build nature can physically overpower a stereo room because they are meant for a large room setting and their sonic signature is just too much for the ears to handle for any length of time. I have also noticed sharpness, shrill, and bright sounding in a speaker to be factors making listening a short time stint. Given that all components are of equal quality, a good speaker blends well with the entire system allowing for music to be enjoyed to hold a lisener's interest at low soft levels or in varied moments of loudness.