Has anybody actually tried these things? They are individual pickups for each string. They look almost like a black rubber cork with a metal post in the center. The idea sounds like it has potential. With a little experimentation you could position each one in the exact right spot for each string to produce the tone you are looking for. Plus I can envision a small board with individual pots and caps in the control cavity to allow tweaking each string's output individually with a final overall tone control on the front of the bass. Of course that kind of tweaking power is way beyond my ability to make use of, but the idea is kind of cool. Question is, what do they sound like?