Room treatment is definitely the best option, but unless you build the room for audio from the ground up (double walls, slanted roof, etc) you are not going to get it 100% perfect. In fact, even then there are likely some improvements to be made.
A typical setup scenario would be something like this
- Setup the speakers as good as possible (lots of guides on the net for this).
- Treat the room as much as possible (or as much as the wife allows you to), of until you feel it can’t be improved any more.
- Fix the fine-tuning (including a house curve you like) with digital room correction.
Of course, only do this if you want a neutral “correct” sound, if you are happy with what you have now, go away from this thread and listen to music instead