Sorry the boards-in-the-port didn't help.
Equalization or a solid state amp are probably your least room-intrusive possibilities at this point. And nothing wrong with room treatment.
Unfortunately I don't have any more inexpensive suggestions.
It is possible that a couple of small, cheap subwoofers, placed one behind each of your speakers and operating out-of-phase, would introduce enough cancellation to smooth things out.
Duke
Equalization or a solid state amp are probably your least room-intrusive possibilities at this point. And nothing wrong with room treatment.
Unfortunately I don't have any more inexpensive suggestions.
It is possible that a couple of small, cheap subwoofers, placed one behind each of your speakers and operating out-of-phase, would introduce enough cancellation to smooth things out.
Duke