Why do some humbuckers have 4-wires and others have 2?
Humbuckers are known for their ability to cancel out unwanted noise and produce a warm, full-bodied sound. But compared to single coils, their sound is typically darker, with less chime and jangle on the top end.
Originally Gibson, who invented the humbucker, used a 2-conductor wire, typically a hot wire surrounded by a shielding ground sleeve. The two coils of the pickup are wired up, in series, at the pickup itself, with the hot wire connecting to one coil and the ground the other, to complete the circuit.
But at some point, some very clever folks figured out that if you moved the connection between the coils away from the pickup and into the control cavity, you could start to do some interesting things with tone.
And so they started experimenting with 4-conductor (really, 4 plus shield) wire. It meant that the start and end of each coil was connected to a separate conductor.
With 4-conductor wire you could still wire the two coils up in series by connecting the corresponding wires in the control cavity, but you could also do some different things as well.
You could, for example, you could choose to ignore one coil entirely, and just connect the other coil to your hot and ground connections, and voila, you have a single coil pickup instead of a humbucker. We call this a coil split, and when you wire in a push./pull pot, you can switch between these two options just by pulling or pushing on the knob. Down for traditional humbucker sounds, up for traditional single coil sounds.
The disadvantage of coil splitting is that you lose the pickup's ability to suppress hum, since the pickup is now behaving exactly like a single coil.
To solve this, you can also choose to still utilize both coils, but rather than connect them one after the other, in series, you connect them in parallel - both coils connect to hot and ground at the same points. The result is that the pickup is still humbucking, but the sound it produces is closer to a single coil than to a traditional humbucker. Pretty rad.
Because these mods offer so much broader sonic potential, we make all our pickups with 4-conductor wire - even if you're not adding any coil-splitting or series/parallel switches to the guitar now. You might want to add them later and having 4-conductor wire leaves that possibility open.
Check out all of the pickup and electronic options available with The Six today.