I was able to eliminate nulls with placement which (easy enough) was to put them the corners next to the KEFs What I'm dealing with now is an uneven frequency response according to REW despite my best effort of placement.
I measured 3 different locations and blended the graphs to setup the subs.
Here's a quick description of the measurements:
20-70Hz, consistently in 85-90SPL
70-135hz, SPL dives to 75
135-200, recovers up to 85ish.
I'd like to even out the frequency response.