I have picked up a really bad hum problem on two of my P basses. As long as I keep a finger on the strings, I am ok. Neither bass is shielded at all. My third shielded bass does not have the same problems. So I am checking out the one and notice it does not have the metal plate under the pickups. How important is this plate for reducing hum? I twisted the wires from the pickups togeather and wrapped them in tinfoil as a poor mans shielding. I then wired the pickups straight to the jack. The bridge ground already went straight to the jack. That didn't seem to help at all. Does the tinfoil mimic shielding (I have it wedged so it is grounded)? I could try switching to coax but I don't want to risk unsoldering and soldering the pickup end unless it would help.