unfortunately I have to cross at a 90 degree several eletrical lines. I hope this does not cause any hum. There is no other way around it. I am running 12 gauge speaker wire cl3 rated. Anyone ever cross several lines of electrical wire and not have any hum. The electrical wire is in metal conduit and my speaker wire is in plastic blue smurf pvc. I guess my best bet is to actually try the equipment and see what happens. Do things like lights, apliances etc. have to be turned on to actually get a hum or is it just in general being in close proximity to those lines.