How far can room treatments solve boomy bass?

Inpieces said it very well. Get some GIK Tri bass traps for the corners of your room. They stack on top of each other and go floor to ceiling in the 4 corners of your room.

In addition to these get one bass wall trap panel for the wall behind your listening position. Lastly get two 244 panels for the first reflection points on the side walls.

This will GREATLY improve your total sound top to bottom. Greatly!

Yes, placement first. Correct amp to speaker matching is also a first step. After this, all systems should use the treatments outlined in my email. All systems will be improved greatly!