I have a Denon2802 and it says I can add a rear speaker to my setup. My question is can I add 2 of them? The bad thing about buying speakers is you have to buy in pairs. I have a Panasound 855 running all 5 right now. So my plan would be to run the center and mains off of the panasound and let my Denon do the surrounds. The thing is there's only one set of rear back wire plugs for surrounds. Can it be done or do I need a higher model?