Moving the couch is the only way to combat this? Bummer. I used test tones and it was very clear where the bass was and wasn't and my whole couch was in a null. 5 feet up was a peak but I don't really want to move up 5 feet. I'll give it a try with one or two feet and see what happens.

The center channel was in phase with the mains.

I may just add a sub to the corner with the leather chair.