Moved from medium attic like room to larger room, everything is too bright

Hi guys, I moved my set up from a bonus room over the garage with slanted walls to our converted media room - which is the old garage. The room is about 450 ft.² with 10.5 feet ceilings. And four large windows. The good news is that I was persuaded to use cryogenically treated Romex directly from the electrical cabinet to the stereo. Which is great… Except I think the size of the room is making music seem brighter and more echoey.

I have a Hegel H390 streaming from a lumen T2. The speakers are KLH model 5 with 2 REL T/7x subs. Played a lot with speaker and sub placement but I think the problem is the volume of the room.

The room is double walled with amazing insulation plus ceiling insulation so that is not the problem. Plus we have area rugs over the hardwood.

I realize that my weakest element in the system is the speakers. So the question is should I save to replace the KLH speakers? And what speakers would work?

Thanks so much, Nadine