Glass and tile room?
That, to me, seems to be your problem.
I've also noticed a few comments over the years about some speakers being best at lower volumes and not so great at higher volumes.
That's probably the room too.
Sound telegraphs the materiality of the surface it comes in contact with.
Glass and tile are going to bright surfaces.
No need to turn your living room into a sound studio. You can make simple and clever choices that pay big dividends.
Stage 1:
Lay down a large, thick rug. When you buy a proper Persian/Turkish etc rug from a good retailer, they will include a heavy felt underlay. This is better sonically than just putting the rug on the ground or using some cheap grip netting.
If you can, get a large enough rug that extends to the front wall/under the speakers.
Or, as in my case, get a separate rug just for your speakers and equipment to sit on. Please don't think this is overkill...it makes a difference to you will hear.
People will easily spend 5 figures on an amp...but balk at spending 4 figures on a good rug. I've learned to value and appreciate rugs because of my audiophile hobby.
Install some good drapes that you can close up for listening sessions.
Stage 2:
Avoid artwork or picture frames with glass. Those music posters in large glass frames look cool but don't help. Choose paintings on canvas and natural hardwood frames. Tapestries, wood carvings and almost anything with uneven, rough or fabric surfaces will help. Try to use symmetry between left and right walls. We have a 60" monitor on the side wall. I place a wool throw blanket over it when I listen.
My last home had a great listening room. I could turn the volume up really loud and it never felt loud or out of control. The room had an amazing grip on the system. Your system should sound just as good at high volumes if the room is well treated.
