This is the upper frequency graph of just the NX Center response in my room. I measured from 40hz to 13000hz and applied 1/6th smoothing.
Here is the lower frequency end of the same graph. In my room the NX-Center has decent output down to 60-70 hz or so. I use my processor to low pass at 80hz anyway so this is a fine response for my room.
I have to tweak the phase (distance) and PEQs on my sealed Rythmik 15’s and adjust all the sub levels since stuff got moved around. That will take a while to get just right to my liking but its close. I really have not had much time with the NX-center and no time at all with all the levels and subs adjusted.