Today I decided to talk about pickup. Yes, everything about pickup, especially on how they function overall. Keep in mind, this is mostly my personal opinion, don't consider my post to be the most correct one, but I'll try my best to provide the best information for you as far as I can.
Introduction to PICKUP101
Here's a short lecture about how pickup works. A pickup is an electronic device that captures the sound of the string of a guitar. It's generally an inductor: a certain length of wire being wrapped into a coil with a magnet on the center of the wrap(imagine a roll-type sushi :p). It has electro-magnetic properties that enables it to capture the string vibration(that also has electro-magnetic properties). When a string vibrates, it disturbs the electro-magnetic field property on the area and this disturbance is being carried by the pickup as a current to the entire signal chain until it ends on the amplifier or PA or whatever is the last destination of the signal path and turns that current into sound.
Pickup comes in different flavors
Just like an ice cream! In terms of coil size: single coil and dual coil(humbucker). In terms of output level: vintage or low, medium, high. In terms of form: the usual coil pickup and the not-so-usual acoustic piezo. In terms of external power requirement: passive and active. And so on, there goes the list.
In depth discussion of coil size
Let's start with the coil size explanation. Single coil pickup usually has a lower output compared to a humbucking pickup. It can create a more acoustic-like tone with some high end clarity that doesn't come out when you're using a humbucker pickup. However, you'll usually get a 60-cycle hum when you use a single coil pickup: that's why people created humbucker pickup. A humbucker pickup doesn't usually have that sparkly high end clarity and acoustic-like tone, but it has a very warm response and will generate a fatter tone compared to single coil.
A humbucker pickup will easily drive the amp faster compared to a single coil pickup because of its relatively high output. A single coil will clean up saturated amp better compared to a humbucker due to low output. A humbucker pickup will easily get muddy because of it's extra warmness, a single coil pickup will easily get harsh on the highs due to its high treble power.
Output level mythbuster: High Output vs Low Output
Now let's talk about how different pickup output levels function on different situations. A vintage(low) output pickup has less wiring turns, weaker magnet and of course weaker sound. A high output pickup has more wiring, stronger magnet and of course higher output that will drive an amp easier toward its saturation level.
Lots of people think that high output pickup is the best. That's not always the case by the way. A high output pickup is very prone of string pull that causes less sustain; it has more wire turns so it has more resistance thus creates muddiness; it has a very high output so you can never get a clean tone out of it without roll-backing the volume knob.
It seemed that high-gain pickup replacement is very popular nowadays with the increasing interest in metal and hard rock music. People with that interest will usually fall into the trick that higher output means better. Well, low output pickup can also do a good job or even sometimes better job at driving an amp into saturation with more definition and clarity although probably less gain compared to a high output pickup. This will help the lower output pickup to easily cut through the mix and sound better during a live performance or a gig.
However, low output pickup doesn't always mean the best. When a single coil pickup is plugged straight into a super clean amp, it definitely has more dynamics which means it follows how hard or how soft you pick the string. Although this is good for some type of music, this can cause some problem especially during recording because you get different output response for different string picking power. But that's easily solvable with a compressor unit; nonetheless, this only happens only when you play on a clean setting.
Active vs Passive pickups
Active pickup: requires battery or external power to operate....Arghh, this one is pretty tough to explain! There's no right or wrong here, an active pickup can bring lots of possibilities to achieve certain tonal range that's not reachable with a passive pickup. Some artists swear that they can get a better clean sound using an active pickup, some even swear that an active pickup help them get better and consistent high-gain sound.
But really, it all depends on how good is the pickup. A low quality active pickup will result in super muddy tone with very low sustain and too much gain. I don't have too much experience with an active pickup but basically even a good active pickup doesn't have the same dynamic that can be achieved through a passive pickup.
So if you need more consistencies rather than dynamics, I think active pickup is the only way to go. Get a good one and you'll deal less with muddiness and all the bad stuffs there. I personally still prefer a passive pickup because the type of music that I play requires wide range of dynamics.
Pickup positions
Let's say I have one pickup and I'm now deciding to put it either on the neck, middle or bridge position. If I put it on the neck, it'll have the highest output level, but with the highest amount of muddiness. Put it on the middle, it'll be bright and glassy; put it on the bridge, it'll be very bright but it'll lose a lot of output level.
That's why people recommend higher output pickup on the bridge and lower output pickup on the neck and middle. This theory is not always true, I mean you can always put pickups of different output level to whatever position you like, but with this kind of setup, you'll get a leveled output level from all position which is good for sound volume consistencies.
I personally like a single coil on the neck, you'll get the best tone ever with a little bit sacrifice on playability. I also like a full size humbucker on the bridge to level out the power of the neck pickup. I don't really care about the middle pickup but as long as I have a single coil in the middle pickup, I'll survive.
Go check out some good pickup manufacturers
Seymour Duncan, DiMarzio, Fender, EMG, Fishman, etc...I personally use lots of DiMarzio pickups, I'm also about to put a Seymour Duncan into one of my existing guitar. I'll post more stuffs once I got that Duncan into its place haha!
Cheers and God bless :)