The null spot is to the side of the listening chairs. I have to be closer to the rear speakers than the front so I can't go with a 360 degree arc, me in the middle equi-distant arrangement.Believe me I have tried every spot short of suspending them from the ceiling. I was hoping for a solution from someone with a similar system using CLS for rear speakers. The sound is very detailed and engulfing as it is with the speakers behind me, equally distanced to the side and rear wall as the front speakers are.Thanks to all.