If you cross power cables and audio cables at 90 degrees and keep power cables 4 to 6 inches away from each other you should have few problems.
As far as I know the only way to stop EMI considering it is EMF causing the problem is to use shielded cables and ground at only 1 end, preferably to the wall outlet screw not your equipment.
As far as I know the only way to stop EMI considering it is EMF causing the problem is to use shielded cables and ground at only 1 end, preferably to the wall outlet screw not your equipment.