You should DEFINITELY think about adding some bass traps to your room. Not only will it smooth out the response, it gets rid of a lot of ringing and boominess. You may not even notice any, but once you hear how your sub sounds without that nastiness, you'll never go back.
For example, here's how my in-room response looks (sub+mains) with a few bass traps:
I was able to smooth it out to this with these filters:
Freq BW Cut/Gain
74Hz 6 -13
45Hz 8 -7
66Hz 2 -4
54Hz 8 +4
37Hz 4 +4
53Hz 3 +2
Before I was using a ton of filters, 11-12, including a lot more boosts. I had
similar results, but I like using less filters this way. Plus, with all the cuts I was using in the BFD, I had to turn the gain on the sub up a lot more - to 55-60% or so. There was a slight hum (presumably from the BFD and the extra connections), although it was only audible with no sound in the room and if I was within 4' from the sub. Being able to turn the gain on the sub down and just amplify a higher signal really toned down the hum as well.
It takes a lot of experimenting. I've probably "redone" my filters 5~6 times now. Now I'm really satisfied with my results and I probably will leave them like this for a long time. With bass traps first, then with the BFD, listening to the "it's cold in here" scene from The Haunting went from "scared, but for the safety of my sub," to controlled, tight bass, hearing every detail and knock and rumble and texture.
