I have an onkyo ht-r520 6 channell receiver, and want to add a couple of outdoor speakers to it. What is the easiest way? These speakers will be to set outside for anbient music, so durability is important moreso than the quality. Also want to add them INexpensivly. Can I do a simple in-line switch? If so, how does that work with a 6-channell system? Another prospect is wireless speakers, but in that case wouldnt all the speakers have to play? I would want the abiltiy to just play either the outside or inside ones. I dont forsee needing to play both at the same time. TIA!