What one change to your room, system, or setup made the biggest improvement?

Going from mp3 to Tidal.  Brought tears to my eyes.

Love the the dummies cuz they solve all the world's problems. Research is comming out a couple treatments with led may help psychiatric problems.guess those guys in the 60s were on to something.enjoy the music and experiments.

Gummies now that I got rid of ai

Well, other than (I"m dating myself) upgrading from DCM Time WIndows to Quad ESLs, in my long life, the most dramatic sonic upgrade occurred when I added an Audioquest Niagara 5000 power conditioner / reservoir.  I expected modest improvements, but the difference was mind-boggling.

My house is completely solar powered, so in retrospect, maybe I shouldn't have been surprised.  Consumer PV inverters are notoriously noisy.

I started out 6 yrs ago.  The Gon was not as helpful and I didnt even know the way to ask the question.. step by step I added this, changed that.  But I  would say the single immediate improvement was upgrading the streamer andbusing USB..  But all the other changes and improvement were worthwhile.

XA25, Room Treatments, isolation, new rack, Electrical filters. dedicated room.  Very good punch list!