I tried both on 0 first, then tried switching the rear 600 to 180, that really created a huge hump in the 40-60hz range. That flattest response came with all at 180, which confuses me because I figured that since the 350's are lined up with the front of the 80's it would be 0, maybe since I two up front spread out 1/3 from each side wall that messes with phase.
Yes, I currently have them daisy chained togethor receiver-350-350-600. I have not noticed any problem. Before I ran a seperate line for the 600 and I didn't notice any difference.
