Treating the ceiling and floor, who else has had great results?

They perform real well if you use them over large areas. By example, I have 28 sq ft on ceiling, 8 sq ft on each back sidewalls and 15 sq ft on back wall. Of course the 6" deep wooden diffusers I have at both first reflection points diffuse in another league, but for a different price too 😊

My floor is wall to wall carpet with padding underneath, and I put 18” triangle bass absorbers in the front corners, but putting anything on the ceiling is not wife approved! Although I was allowed to put 6, 2’X4’ absorbers on the walls.

All in all I’m pretty happy with the sound in my room.

I have treatments on the ceiling and it really made a significant difference,
it would’ve been a big mistake to overlook treating the ceiling,

I treated my ceiling like I did my side walls for a high end 2 channel system in 4000 cubic feet space. The floor is carpeted. Lastly, the speakers are pulled out from the front wall with scatter plates behind them. Bass absorbers are inserted in the front corners. Locations for the admixture of absorption and reflection panels were determined based on 1st and 2nd reflections. The sound detail is magnificent, because the structural boundaries have disappeared — especially for depth of the sound stage. I found that strong equipment is made better by sound treatment of the listening space.

I have not specifically treated the ceiling, and think that would be a tough to sell with my chief decorator/LOML. However, there’s a textured ceiling, and two ceiling fan structures that may help with some diffraction....perhaps I could suggest a couple of well designed decorative medallions around them.

The floor was easy, with thick wall to wall carpet. The suspended floor underneath...not so helpful, but I bet I could get away with a few extra lolly posts in the crawl space below.

It's not ceiling/floor, but the large fireplace structure on the wall behind the speakers seems to offer some diffraction help. I’ve been bugging her about installing some book cases to further enhance that effect. We shall see!