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I have two primary data sources for this table, 1) my own measurements labeled as "self", and info from vendors labeled "vendor". In the case of a "vendor" source, only the type of pickup, magnet type, metal types (steel, AlNiCo, brass, etc.), DC resistance and inductance, is known. If atleast this much is not known, I have not included the data here.
Because vendors often provide inductance, but not bode plots or capacitance values, the values for capacitance and damping for "vendor" sourced data is estimated based on the average measured values of pickups with the same physical layout and metals. If you sort by "vendor", you can see these estimated "dB" and "pF" values, and they are derived from the non-vendor data of this same table. Since these capacitance and damping values tend to be close for a given type of pickup (within about 10%), and are proportionately small in relation to the pickup's inductance, the resulting EQ data and plotted curve that is derived with the inductance and these estimated values is adequate for approximation and comparison.
The two columns that are likely of most practical use are
Loaded Res. Freq. (pF) w/470pF and
Inductance (H).
- The
Loaded Res. Freq. (pF) w/470pF will indicate how bright and clear the pickup tends to be. The 470pF capacitance simulates the effects of a typical guitar cable.
- The
Inductance (H) strongly suggests the voltage output that can be expected, and along with capacitance, determines the resonant frequency.
Though, due to lower magnetic reluctance, if a pickup has steel poles, it will likely be 2dB to 3dB louder than a similar pickup with AlNiCo pole pieces, regardless of the inductance or magnetic strength.
Both inductance and capacitance factor in to the resonant frequency, but the inductance is the dominant value.
- Note that the DC Resistance does not correlate strongly with either output or frequency response. It mostly indicates how many turns of wire a pickup has on the bobbin(s), for a given gauge of wire.
- Note that "Self Res. Peak (dB)" is a "raw" value, and is only applicable if your guitar has no volume or tone pots, and the pickup is wired directly to the output jack. The Loaded peak is more realistic.
- Note that "Self Res. Freq. (kHz)" is a "raw" value, and only applicable if you were somehow using no guitar cable. The "Loaded Res. Freq." simulates typical cable capacitance.
Helmuth Lemme has a good article on the significance of these value in determining how a pickup will affect the amplified sound of the guitar
"Pickup Measuring Technique"
It's also important to consider that
wider pickups cause greater comb filtering of high frequencies, so it's best to compare pickups with the same foot print. The bode plots comparing a Fender single coil and a PAF type humbucker would be misleading, since they don't align under the guitar strings in the same way.