The Resonant Peak of a Pickup, What is it? and Does it Matter?
The Resonant Peak of a guitar pickup is one of these terms that we don't hear quite as often as DC resistance. The interesting thing is, The Resonant Peak is more or less the sum of all the other measurements. What do we Mean?
The DC Resistance tells us how many windings are on the coil based on the wire gauge and bobbin size. The Capacitance of the coil gives us an idea how it will process high frequencies based on the losses that happen within the coil. The Inductance is the overall ability of the coil to do it's job based on the previous measurements.
The Resonant Peak of the pickup is the frequency that the pickup can most easily reproduces based on all these other measurements. Guitar pickups, by design, and because of the gives and takes of electronic theory, do not reproduce all frequencies with equal efficiency.
What does Resonant Peak Mean For Your Tone?
It could be said that the resonant peak of a pickup is really the center of his tone. The trick is, when we put other components in front of or behind the pickup (pots, caps etc) the resonant frequency of the entire circuit becomes variable. (because the Pots are variable).
The Resonant peak of the pickup by itself with no other resistors (pots) or capacitors is more or less fixed. Since most people don't use a pickup by itself, the entire circuit really needs to be looked at together. This isn't to say it's not important. It can still be used as a baseline.
It is important to understand the interaction between the other components in the circuit. Watch the video below to get some ideas on how these interactions work.
https://youtu.be/ZCzZfKY2QM0