Humbucker Series vs Parallel Output Loudness Level

[pablogilberto]

Hey Gnuts!

I wanted to ask your insights regarding the output level produced by pickups combo when they are in series or parallel.

For humbuckers, I understand that a coil split will result to a lower output since only 1 coil is active.
But for Series vs Parallel, I'm not sure why the output level of a Series pickup is much greater than the parallel?
Both coils are still active.

I know that series will increase the inductance and lower the capacitance (lowering the resonant freq) while the opposite is true for a parallel combo.
Is this the correct reason or I am missing something?

[blademaster2]

Human hearing is not a linear thing, of course. I have S-P switching on one of my pickups and it always surprises me how little the perceived volume actually changes between these selections.


You can hear it, but it is not a huge change despite the signal doubling.

[ziggystardust723]

- Hi Pablogilberto,
2 Bobbins HB in Series:
- 4k + 4k = 8k 0hms
> in Parallel (like 2 Stratos):
- 4k + 4k = 2k 0hms
> 0nly 1 Bobbin :
= 4k 0hms .
> 2 Stratos, Ex Neck & Middle:
- 6k + 6k = 3k..
when the Middle is RW/RP:
You can Add the 2 Bobbins in Serie:
- 6k + 6k = 12k
> For Middle & Bridge,
- But a lot of guys don't think to do this way..
- Bye, Ziggy (from France, 20h18)

[JohnH]

Apr 22, 2021 7:06:08 GMT -5 pablogilberto said:

Hey Gnuts!

I wanted to ask your insights regarding the output level produced by pickups combo when they are in series or parallel.

For humbuckers, I understand that a coil split will result to a lower output since only 1 coil is active.
But for Series vs Parallel, I'm not sure why the output level of a Series pickup is much greater than the parallel?
Both coils are still active.

I know that series will increase the inductance and lower the capacitance (lowering the resonant freq) while the opposite is true for a parallel combo.
Is this the correct reason or I am missing something?

The bulk of the volume is generated in the mid range, and its simply a matter of what voltage swing the pickups or coil combinations can produce. To picture this, imagine the coils, generating an ac signal, are analogous to 1.5V battery cells generating dc voltages.

one cell makes 1.5V
two in series makes 3V
but two in parallel still makes 1.5V, it just has higher capacity to deliver current and will last longer. But back to the pickup, its the basic voltage output that gets amplified to create volume.

The tonal differences are noticeable though, and at that point the dc cell analogy is not so useful.

[ziggystardust723]

Hi Pablogilberto,
Did you read.?
I'd Answer well to your Questions..
- Ziggy (France, 23h32)

[guitarnerdswe]

Regardless of any theoretical numbers, I definitely find parallel to be quieter than a split.

[gckelloch]

It depends somewhat on the impedance of the pickup as well as where the resonance peak is. AFAIK, typical ~8K Ohm/4.5H PAF's can lose some bass in parallel mode, and the resonance peak can then be above where the Steel core caused eddy currents reduce the high end enough so there is no significant peak, and the whole signal drops down a lot. Higher impedance/inductance Steel core HB's in the 6.5-8H range wound with thinner wire won't lose as much bass in parallel mode, and the peak can then ideally be in the 4~4.5kHz "bell tone" range, depending on the cable capacitance b4 the first gain stage.

[guitarnerdswe]

May 2, 2021 20:38:42 GMT -5 gckelloch said:

It depends somewhat on the impedance of the pickup as well as where the resonance peak is. AFAIK, typical ~8K Ohm/4.5H PAF's can lose some bass in parallel mode, and the resonance peak can then be above where the Steel core caused eddy currents reduce the high end enough so there is no significant peak, and the whole signal drops down a lot. Higher impedance/inductance Steel core HB's in the 6.5-8H range wound with thinner wire won't lose as much bass in parallel mode, and the peak can then ideally be in the 4~4.5kHz "bell tone" range, depending on the cable capacitance b4 the first gain stage.

Definitely explains why I don't like low output HBs in parallel. No low end, hi-fi high end.

[gckelloch]

As I said, the resonance peak of a low to med inductance (output is not the same as inductance) Fe core HB in parallel would generally be above the range of a typical 12" guitar speaker and more reduced due to how a Fe core pickup rolls off the high end, so it's actually not as bright sounding as a high inductance Fe core HB would be in parallel. "Brightness" is heard by human ears in the 2-5kHz range with a ~5dB sensitivity increase in the 3-3.5kHz range as seen in the F-M loudness curve. I'd go for something ~8H for the best results in series or parallel with an average ~360pF cable b4 the first preamp stage.

[guitarnerdswe]

May 3, 2021 19:39:51 GMT -5 gckelloch said:

As I said, the resonance peak of a low to med inductance (output is not the same as inductance) Fe core HB in parallel would generally be above the range of a typical 12" guitar speaker and more reduced due to how a Fe core pickup rolls off the high end, so it's actually not as bright sounding as a high inductance Fe core HB would be in parallel. "Brightness" is heard by human ears in the 2-5kHz range with a ~5dB sensitivity increase in the 3-3.5kHz range as seen in the F-M loudness curve. I'd go for something ~8H for the best results in series or parallel with an average ~360pF cable b4 the first preamp stage.

Sorry, I should have said PAF-style instead of low output.

[gckelloch]

Oh, that's fine. It's important to understand that output doesn't necessarily correlate to inductance i.e. a C8 magnet in a PAF type won't increase inductance but will produce more output at the same string distance than AlNiCo II. In fact, a C8 core pickup may well have higher output at the same distance, but considerably lower inductance than an AlNiCO II core pickup with the same coil.