This might help you understand... it is from an old Hybrid post I responded to:
The problem when you overwind a PAF style 42 guage wire pickup(59 Model, Seth, EVH, etc.) is that it starts getting garbled sounding above about 9k just as MJ has informed you...
To achieve a more beefy tone and retain clarity, you need to step to a thinner wire and wind more turns... ala the Custom models which use 43 guage wire coils wound to just above 14k which is the optimal range for tone with that wire...
The next step is the JB & Distortion which are wound up to about 16k with 44 gauge wire which is the optimal range for THAT wire.
Each wire has its "sweet spot" for tone and response and they all end up with about the same size coil... each wire also produces a unique set of harmonics
The comprimise when producing a "hot" pickup is that you lose some of the articulation and dynamic response of the PAF and start to suffer from compression due to the signal travelling through a greater length of thinner wire. There are benefits and comprimises with each unique design.
With the Hybrid you get a blend of the different gauge wires qualities... also, each coil has a different resonant peak so the combination is less "peaky" or "one notey" than a standard humbucker. The mis-matched coils also cancel less harmonics so the tone is more complex and posseses some qualities exclusive to single coil pickups.
The coils are actually not very mis-matched since they have roughly the same amount of copper on the coil... you can't just use the resistance reading as a balance indicator
The difference in resistance readings is because a 59 coil is wound with 42 gauge wire and a Custom coil is wound with 43 gauge wire which is thinner and electronically more resistive, add the additional turns it takes to fill the coil and your resistance reading is going to be a lot higher than a 42 gauge coil... the key factor is that they have about the same amount of copper on the coil which is what reacts to produce sound when the magnetic field is stimulated by the vibration of the strings.
An example of a widely mis-matched humbucker is the FRALIN UN-BUCKER which has coils of the SAME gauge wire wound pretty far apart... the resistance measurement may only be 1k or so, but that is with 42 gauge wire which will produce 2 coils with a big difference in the amount of actual copper... I tried one of those and did not like it at all... the resonant peak produced by that 3.5k 42 gauge coil was shrill sounding to my ears.
I hope I have explained this in understandable terminology...
There is a consistant misunderstanding on the forum of how pickups work... ESPECIALLY in regards to resistance measurements... different gauge wires produce a different responses, harmonics and tone... that is why there are different models made with 42 gauge(59 Model, JAZZ, APII, etc), 43 gauge(Custom) and 44 gauge(JB,Distortion, etc...)
Seymour has nailed the optimal winds for wire each of the standard gauge & type and that is why his pickups are generally regarded as the best... the majority of all the different models available are just variations of magnet type/size, coverd/uncoverd, potted/un-potted and different polepieces.
Hybrids made using Duncan coils are the best pickups I have ever heard...
The finest Bridge pickup being the Alnico 59/Custom Hybrid... the JB/Custom is also very cool for more modern tone...
The Neck pickup of choice is the 59/Jazz Hybrid...
DiMarzio has patents on this type of design so you will not be seeing them in the Duncan lineup anytime soon.
