: The treatments seem to be making a small difference, but IIUC, you only have two bass traps, correct? Based on the waterfalls, which are showing severe bass ringing, you will need quite a few more traps to make a measurable difference. Remember, traps are most effective when they straddle a corner, not when they are placed flat on the wall. If you look at the pictures of my room (My Setup link in my sig), you will see that I use the intersection of the wall and the ceiling as spots for bass traps, as well as every available intersection of two walls, and even a ceiling cloud. It takes a ton of traps to fix a bad ringing problem--don't know if WAF is a factor, but a ton of traps is not always that visually attractive.
The frequency response is not terrible, but could be better. I have been using REW for years, and have NEVER used the room sim tool. Shows you what I think about that feature. IMO, additional subs are your best bet to improve frequency response, as well as "real" sub placement experiments (not the room sim).
I don't know what to say about the door. Personally, I would leave it alone. You have other options--more subs, better placement, more traps, room EQ, etc.