If you are not yet satisfied; I'd try 'better' speakers with the Rotel, first.
I'm talking only about 2 channel music here.
I had a Rotel RX-1052 powering old Boston Acoustic T-830 acoustic suspension speakers. That combo sounded great at low volumes. I later upgraded to Canton Ergo 1002 DC bass reflex design larger towers. They need to play quite a bit louder to get everything out of the music. Both are rated at 90 dB @ 1W @ 1M, but the Cantons actually play louder at the same volume setting.