The title pretty much sums it up. My client decided to add another pair of speakers to his deck on his own, ran the wire himself back to the in-wall control box which we just happened to pass through with a 16/4 feed to the amps. Now I hafta make it work... Don't need a lot of watts (residential) and an auto-on with signal would be really handy. Had I not already purchased one pair of 4 ohm outdoor speakers I'd get two pair of 8 ohm speakers,or I'd be looking (and may still have to go) in that direction. A new wire is not practical or even possible, which precludes the idea of a four channel amp. Any suggestions for a suitable amp?