Guitar Pickups
How do I decide which pickup is right for me?
Depending on what sound you want to get out of you guitar, take the following into consideration.
Single coils pickups are naturally brighter than humbuckers and have their own distinct sound. The downside is that they will pick up hum from alternating currents which will travel with the signal from the string to your amp. This causes a much noisier effect when distortion is added. 250k potentiometers (or "pots") are commonly used for single coil pickups.
Humbuckers are wired in such a way that hum from alternating currents are cancelled out. An inherent feature of a humbuckers is that it has less treble and a fatter tone. Humbuckers also have a naturally higher output than single coil pickups. To compensate, 500k potentiometers are used for humbuckers because they will attenuate less high frequency.
Different magnet materials used in a pickup will give different tones. Alnico 2, alnico 5, and ceramic are the 3 most common types.
Alnico 2 magnets are the clearest signal of the three. They also have the cleanest sound.
Ceramic magnets are the least clear and dirtiest sound of the three. They are distorted and generate a rich palette of harmonic overtones.
Alnico 5 magnets are a good balance between alnico 2 and ceramic. They are best for players who switch between clean and distortion settings or just don't want either extreme.
String vibration is widest and most clear at the 12th fret and more distorted closer the bridge and nut. Because of this, common configurations are for a guitar to have a ceramic magnet pickup in the bridge position and an alnico 5 magnet in the neck position or to have an alnico 5 magnet in the bridge position and alnico 2 in the neck.
Neck pickups will have a lower output volume compared to the bridge. This is because the string movement is much greater at the neck. The pickup type doesn't always change. It is more common to have two humbuckers of the same magnetic type in one guitar.
Active pickups run off of batteries. The sound is usually compressed and equalized by electronically shaping the sound of the pickup. They have more output than passive pickups and will drive an amp's preamp stage into distortion easier.
In a guitar with three pickups, the middle pickup uses the neck pickup as the middle pickup as well, not the bridge. So it would be bridge/neck/neck. Most companies don't make a middle specific pickup.