crushing day wrote: Ash did explain to me on the weekend why some pickups with higher DC ratings are weaker than others with lower ratings (resistance maybe?) ... but i can't remember now
Numbers like "15k" as often quoted for output are actually DC resistance. That tells you a bit about the combined effect of how much wire is wound on there and how thin it is. But that all means nothing when there's an ac current induced in the coil from a vibrating string.
The usual and very general rule of thumb is a higher dc resistance equals higher output, but its only 70% true. There are plenty of 12kOhm (12,000 Ohms resistance) pickups that will out grunt other 15kOhm pickups.
The difference has to include the magnet type, construction, proximity to the strings and pole peices, the polepeice type blah blah...
Some brands like DiMarzio give a voltage output figure which is better, but only applicable for the A string tuned to 220Hz and plucked with a standard force with standard pole height. Some pickups will be louder in the bass or treble or whatever.
The best measure is inductance measured in milli-Henries (mH) which only Bill Lawrence gives data for. Inductance is still not a perfect representation, but pretty reliable because it takes into account magnetic structure and frequency response almost regardless of pickup type.
Higher inductance = higher output = darker tone
Assuming you are considering pickups with identical construction, magnets and wire you can make the same guess based on resistance, but it won't apply linearly or accurately if you change the other parameters, like comparing a single coil with a humbucker or an alnico humbucker with a ceramic humbucker or a rail with a stack etc.
Taking all that into account, a 15k neck pickup in an invitation for muddiness in many cases.
