4-wire pickups give you access to both sides of both coils in the pickup. This gives you total freedom to wire it up any way you want to. You can add switches to your control system to:
- Coil Tap: This shorts-out one of the coils, leaving a single-coil pickup. It also defeats the hum-bucking characteristic, sometimes causing noise problems.
- Parallel coils: This retains the hum-bucking properties of the pickup, while reducing the output level and producing a sound that is similar to a single-coil.
- Series coils: This is the classic humbucker configuration, with high output and typical humbucker sound.
- Centre Coil Split: This connection uses one coil from each pickup of a two-humbucker setup to create additional voicings, with the coils in-phase, or out-of-phase.
Go to the >DiMarzio< website, click on any of the humbucker links, and then click Installation to get detailed wiring diagrams. One of the reasons I like DiMarzio is the way they assume that their customers can make use of this kind of info, where the Seymor Duncan website takes the approach that their customers are clueless types who will be getting a tech to do the installation. That said, I have heard the JB - '59 setup being recommended by players who should know.[/font]