Speakers or room

There is no doubt whatsoever that it is the room.  Tile floors and large glass windows is tough to work with.  Curtains over windows will help along with an large area rug over the tile and lots of furniture, lamps, plants, etc.  Anything to break up the sound.  Since you talked about wife acceptance factor I doubt wall treatments and bass traps would be acceptable.  Move to a smaller carpeted room

One of the general concepts I've heard for room treatment is to treat one each of the opposing walls.  Making the wall opposite the speakers less reflective seems like a good way to start. Rugs are awesome too, + and + to above comments.Are your speakers on the long wall or the short wall?

Read up  on acoustic treatments. Plenty of info available.
The  untreated room is trashing your sound. 

select-hifi, talking of which, when I've been comparing two different audio receivers ( from this website: https://chooserator.com/compare-av-receivers ) models called  Marantz SR7011  and  Yamaha RX-A3070BL  -  I've chosen the most functional, which in my opinion Yamaha is. It can demonstrate really powerful and dynamic, but at the same time soft sound.