From what I can tell. Your problem could be the combination of several things going on at once. That speaker is peaky by nature of its design Totem Rainmaker measurements. There's a peak from around 5khz beyond 10khz. This could be one of the factors causing fatigue. Also the speaker is a tough load and may cause the amplifier to run out of steam at higher volumes. The source of any system is important...too much of a bad thing(badly compressed music)can cause major fatigue. I agree a good Dac will also help with the fatigue.
You can play with the room treaments but that's not going to change the design of the speaker. Hopefully your listening room isn't bare.If I were in this situation, I would most likely dump the speakers first for something less peaky. Next would be to add a decent Dac.
If you really like the speakers.You could try to bandaid the problem with a digital equalizer. One more thing ..you could add a sealed subwoofer to balance out the sound a bit as the speakers start to roll off at 100 Hz. Allow the sub to do all the work..say below 80Hz..relieving the speakers of the lower bass duty. You may find yourself listening at lower volumes with better tonal balance in the music.
You can play with the room treaments but that's not going to change the design of the speaker. Hopefully your listening room isn't bare.If I were in this situation, I would most likely dump the speakers first for something less peaky. Next would be to add a decent Dac.
If you really like the speakers.You could try to bandaid the problem with a digital equalizer. One more thing ..you could add a sealed subwoofer to balance out the sound a bit as the speakers start to roll off at 100 Hz. Allow the sub to do all the work..say below 80Hz..relieving the speakers of the lower bass duty. You may find yourself listening at lower volumes with better tonal balance in the music.