I picked up an Onkyo TX SR600 tonight at the Crutchfield outlet in Charlottesville, VA. I have not completed the install yet, but I have been contemplating the following. I have noticed that people have been able to localize the rear channel in 6.1 surround. It has been suggested that maybe 6.1 surround rear channel may be less localizable if you use 2 speakers on the rear wall in series (because in parallel the impedance would be too low. I a have another suggestion. Use 2 speakers wired in series. Have the speaker wired out of phase. Think about it. Speakers wired out of phase are less localizable. With the speakers out of phase, would not the speakers be even less localizble. I will try this tomorrow or the Sunday. We will see how it sounds.