Setting your pickup height too low would cause your pickup not to be optimized for your guitar.
Ceramic magnet single coil adjustment height.
Because the magnetic field or the part of the string being sensed by the pickup is soooo much smaller and more focused with a single coil even microscopic changes in pickup height make a perceivable sonic difference.
They rely on support often a foam strip placed underneath in the pickup cavity to push the pickups to the correct height.
By adjusting the amount of foam in the cavity you re able to determine the height of the pickup.
You see ceramic is easier to come by than alnico making it a cheaper magnet to make.
P90s blade style pickups ceramic magnets and lace sensors all have different suggested pickup height but it s up to the player to.
As far as pickup height is concerned humbuckers are a whole different animal from single coils.
Humbuckers can run a little closer to the strings gibson recommends 1 16th of an inch for the bridge pickup and 3 32nds of an inch for the neck because their magnets aren t as powerful as single coils.
Setting the pickup height too high can cause interference with your guitar strings 2 setting pickup height too low.
Most traditional single coil pickups only allow for height adjustment of the pickup as a whole but on the mfd pickups the pole pieces are individually adjustable.
Ceramic magnets are made of ceramic surprise.
If you position this at the same height as the original pickup chances are your guitar will be significantly louder at the bridge position than at other pickup settings.
Your magnetic field floats above the pickup and if your strings are out of the field you won t get a rich full tone.
By some players the ceramic magnets are given a bad reputation when compared to alnico which is probably due to their association with cheaper instruments.