Mr. Brody - Over the weekend I attempted to do the same thing. I bought a Nutone IMA-6604. However, when I brought the speakers home - was awating delivery of the main unit - I found the wiring did not match. The current wiring is a flat grey six wire imbedded wire with female end which plugs into speaker. The new motherboard requires a seperate six point connection. I contacted Nutone and found there is no wiring harness to make the adaption. The 6604 is the upgrade from the 6004. You can go to the Nutone site to find a dealer in your neighborhood. The other alternative to the rewire is to strip the wires bare. However, they are very small. I suggest you take one speaker off the wall (Just remove the two screws) and see what wiring you have. If you find a better solution, please post it here. I'm interested in upgrading but will not rewire the house nor take the chance of stripping the wire. BTW - the system w/6 indoor and one outdoor speaker ran about $1,350. No telling what a rewire would cost.
