I have an old Jazz bass copy that I want to put a real jazz bass neck pickup in. As the bass sits now the pickup cavity is 4x2 inch and 1 inch deep hole in the body where the pickup would go. Now do I just use a jazz bass pickguard as a guide and just mount the pickup by itself with nothing supporting it. Or should I plug the hole and route a proper pickup cavity. If I do this how deep should the routing be? What effect does not having wood around the pickup have?
I'd just leave the hole as it is and put it in. The pickup has mounting screws to support it. That's all it needs. Doesn't make a difference in sound, really. Plugging and re-routing would probably sound worse.