I am using the Zone 2 of a Denon 2307ci to power 5 pairs of speakers throughout my house. I am using a Dayton 10 location distribution module to do so. I have 1 dayton impedance matching VC (that I added) and the rest are Russound installed by the builder so I don't know if they are impedance matching and don't know how to tell but I do know they are less than a year old. Anyway, the problem is, in 2 of the rooms, only 1 speaker works. In the other 3 rooms, everything is fine. I have checked and double checked the connections and everything looks fine. The other odd thing is that I swear when I orginally turned them on after setting this up last week, both speakers in said rooms were working great. Now they are not. Is this an impedance matching problem? If so, how do I tell and if not, any suggestions on what to check next?