I have a guitar which has two pickups right next to each other. When either pickup is turned on, I can tap on the other pickup and hear sound. As I move the pickups away from each other, the sound picked up from the other pickup lessens. At about 1.5" inches away, the sound is no more.
So, it seems that the magnet from one pickup is picking up from the neighboring pickups coil. Ultimately, I'm not sure how much 'bleed' there is, however, I'd like to know if it's possible to place a thin strip of material between the pickups which will stop this from happening and not impact the sound of either pickup?