It would be great though if I could solve this without subs. I wonder if bass traps would allow me to turn my subs up more while still retaining cleaner bass.
So here's how that works. In order to get even bass the conventional way you have to turn the subs up loud enough to bring the drop-offs up to where they sound good. This means having way too much energy at other frequencies. So you try and damp that out with traps.
But the traps and loud spots are only in certain places, while the excess energy is everywhere in the room. This physical energy excites the walls, the whole room, and physically dissipates over time. Its the dissipation of this energy that smears and muddies bass response. There really is nothing you can do about it. More and more traps leads to more and more EQ and you just never get enough.
What's funny is everyone knows the last thing you want is to have an overdamped room. A certain amount of acoustic reverb is nice and helps create a sense of spaciousness. Too dead and the room sounds... dead. Yet that is exactly what a lot of these bass trap people are having you do, only with bass instead of midrange and treble. So you don't notice it when you walk in the room the way you would with panels all over the walls that kill the sound. But its the same thing, only lower in frequency.
You don't need 12" or 14" subs. Those are for when you haven't figured out the answer is more subs and still think its more sub. That "s" makes all the difference in the world. You can easily use 10" subs. I have four of em. Its not how big. Its how many. And where. Dispersed asymmetrically around the room.
This will cost less, take up less space, and work better than all other options. I really cannot think of a single objection, other than the mental effort required of any new idea.