My question is why would you need 2 subwoofers?
My room is odd shaped, with lots of corners, part with a cathedral ceiling and a bridge, and part w/ plain 9' ceiling. When I had 1 sub, no matter where I put it, the sub volume was different from chair to chair. You could hear a significant difference in bass volume, even between our 2 main chairs just 6' apart.
Think of a small pond with several stumps, boulders, and an irregular shoreline. The ripples from a stone dropped in the water bounce off the stumps & boulders, and off points on the shoreline at different times. So you have primary ripples and reflected ripples.
In some places the ripples have opposing directions and tend to cancel each other out. In other places the ripples move in the same direction and tend to amplify themselves. So different points in the pond see different intensities of ripples.
It is the same with sound waves in your room. 2 subs in different locations can even out the bass ripples, so people sitting in different chairs hear a similar intensity of sound.
Plus, 2 subs make it easier to rattle the windows, shake the floor, and thump you in the chest. Who doesn't want that?