Room is way too bright.

Not just eq. DSP! Room correction using DSP even better. Problem solved.

Not to complicate things further, but there are also first reflection points on the ceiling.  It never ends. 😖🙄

2x4 room panels on the 1st reflection plenty of carpeting 

a AQ niagra 3-5000Line conditioner  with hurricane power cord ,with Power correction  engaged the ground noise is removed as well as signal is smoother for high frequency noise tips up the high frequencies.

Yes @Audioman58!  Don't overlook the nice wool rug in front of the speakers.

Also many systems can be inadvertently tuned to brighter with some cables containing silver.They seem resolving at first...

The issue is not the output of the speaker into your room, it is the output of the room into your ears. This is the fundamental misunderstanding about equalization and all the other proposed fixes that don't fundamentally change your room acoustics do not understand. Turning down the treble, via whatever means will only dull the direct sound making things worse. You still have a very relective room. As some have mentioned, heavy sound absorbing curtains or vertical blinds will help. Lightweight shades will not because they can't absorb acoustical energy. Acoustical diffusers will even out the room but do not absorb HF energy. Acoustical panels, 2X2 or 2X4 ft on the ceiling will also help, as can a heavy rug with pad.