Hi Pez - Good point,
I put up some inexpensive acoustic foam at the first reflection points (side walls, ceiling) once many years ago.
When my wife got home from work, she was not happy (I don't have a dedicated listening room). She did not like big foam panels in our family room.

I have a spare bedroom upstairs I can use as a dedicated listening room, but it is so small (think large elevator), that I fear that it's size would cause more problems than acoustic treatments would solve.?
I know my room would benefit greatly from bass control too. That may be another reason I haven't bothered with adding a sub with this new setup. I have learned from past systems that bass response in my room is very uneven. I have a lot of problems with larger floorstanding speakers and/or subwoofers in my room.
Since I didn't get away with the acoustic foam panels, I never dared trying to sneak bass traps into the room.

My best compromise til now is listen in the near/midfield position away from all room bounderies at low to moderate volumes.

But thank you for the advice. I have no doubt that you are right. In many rooms, acoustic treatments can often return the biggest system improvements for the money spent.
Oh...I have seen absorptive panels "disguised" as paintings. Very clever. I can't get away with hanging one on the ceiling though.
Also I have learned that plants behind the speakers can help with dispersion. That's an old "trick" - but a good one.
If anyone knows "sneaky" (visually aesthetic) ways to tame bass, please pass them on. My room would definitely benefit from bass control.