The brightness can be explained by resonances in the upper mids, lower treble, and upper treble of your speakers. They have excess energy from 700 Hz to 2 kHz and again from 10 kHz and up. The fact that you aren't using a sub makes them thin, too, which exacerbates the problem.
You can try the EQ settings found here and see if it helps:
https://pierreaubert.github.io/spinorama/eqs.html
I made your corrections on the link with APO Equalizer and I also considerably reduced the mids and trebles for testing, it really helped, I also made an acoustic treatment with foams on the walls, the tonality was a little more natural with all this, but in a considerable level, the sound is neither pleasant nor musical so to speak, I still feel the pains in my ears especially in the right ear.
This is a review and detailed measurements of the Pioneer SP-BS22-LR desktop/bookshelf budget speakers. I purchased them recently from Amazon for US $118 including Prime shipping. But I hear they go on sale for much less money. The build quality is incredible given the very low price: The...
www.audiosciencereview.com
I think these measurements are the most accurate. Would you say that even with EQ and treated room, these resonances could be causing harshness in the sound? What could be another cause? I usually feel pain and discomfort in the ears after listening for more than half an hour, but at certain times it feels ''normal'', until I feel pain again, I've checked it out and it's really not something with my ears, because elsewhere it doesn't I feel none of it.
I'm still using these same speakers, I had to invest in other things and due to covid and so on, I still couldn't buy a better one (I'm also in doubt about which to choose). I replaced the SMLS SA100 with the Allo Volt+D amp and I'm using the Topping E30 DAC with the LPS Allo Shanti, obviously the sound has improved a lot, I would say it's more tolerable now, but it's not that pleasant and musical sound, I found this very strange since I created this thread, I still think.