OP if you’ve addressed the first 50% of the issue, the ROOM and the electricle grid.
The other 50%, is Gear, speakers, cables, and isolation. The least expensive for the return is isolation and decoupling speaker enclosures, from the rooms floors, ceilings, and walls..
You can hear a difference because of clarity, not through a fog so to speak.
When thing don’t sound right to my ears I try to change the different tones to compensate, when in reality cleaning up smeared multi bass signals was the issue all along.. Clarity and Definition coupled with the imperfect perfections of valve harmonics.. Different story, ay?
Room (low expense)
Electricle and cable routing (low expense)
Decoupling (low expense)
Gear (EXPENSIVE)
Speakers (EXPENSIVE)
Wisdom (priceless)
Regards