Not seeing the sound

The sound is quite 3D now. There's width, height and depth, if that makes any sense. Truly, a remarkable thing to experience in my own listening room.

The sound is quite 3D now. There’s width, height and depth, if that makes any sense.

Yup, that’s it. As stated above, the speakers have disappeared.
You should also now hear quite a difference between many digitally remastered (compressed) recordings and the original versions. The original will have depth and space between instruments, e.g., the singer will be forward and center, while the drum kit will be located at the back of the soundstage.

When I achieved this desired quality in my system, I stopped buying compressed remasters and went looking for the original CD's. This applies mainly to Rock and I now shop for music on Discogs.

Yep, lowrider. You nailed it.

I see your voice!

Reflections and edge difractions are what kill the imaging. Speakers should be 3 feet minimum from any side wall even if that means they are closer together than you would really like.