Have you played around with speaker location, like maybe a few feet from rear wall or so? Possibly a tad closer together in conjunction as well. Speaker location relative to walls is a big factor usually for good separation and sound stage. With that, can also come less congestion and better detail.
Start with a good mono recording and get a solid and focused image between the speakers first. Then try some things in stereo. IF mono recordings are imaging clearly that is usually a good omen for stereo.
After that, you might try some sound absorbing panels or other sound absorbing materials or room items at first reflection points along the walls based on your primary listening position.
Then any other tweaks if still needed from there.
Start with a good mono recording and get a solid and focused image between the speakers first. Then try some things in stereo. IF mono recordings are imaging clearly that is usually a good omen for stereo.
After that, you might try some sound absorbing panels or other sound absorbing materials or room items at first reflection points along the walls based on your primary listening position.
Then any other tweaks if still needed from there.