Um, no. Humbuckers are indeed a pair of single coil pups, but the hum cancelling is accomplished by winding one of the pickups in the opposite direction and reversing the polarity of its magnet(s). That makes them pick up a signal from the string in the same polarity with each other, but any ambient hum is picked up in reverse polarity by the second coil, hence the cancellation or "bucking" effect.