Post by antigua on Mar 4, 2019 22:38:55 GMT -5
I saw a conversation on another message board about whether RW/RP wiring causes an audible difference aside from EM noise cancellation. Videos depciting crude demonstrations such as this one don't dispel the idea that there might be a difference.
As far as I know there is no clear reason why the two wiring modes should sound any different, aside from the lack of noise. One theory I saw that RW/RP might cancel microphonics as well as noise, and that the cancellation of microphonics might account for the difference, but that most likely doesn't happen. First, if this were the case, typical humbuckers would be averse to microphonics. Second, microphonics are just as likely caused by dynamic capacitances as grounded metal parts vibrate, and those voltages are not cancelled out by RW/RP coils, which is why humbuckers still feature shielding, despite the humbucking.
Another reason floated was that the RW/RP middle pickup will "push" on the strings while the neck and bridge pull at it, but it's obvious that the magnetic interaction between the magnets and strings are localized, and the guitar strings so magnetically unsubstantial, that the two outer magnetic fields will not impose any sort of repulsive force towards the middle.
Another possible reason they might sound different is a change in the parallel inductance. It's known that with a side-by-side humbucker, the coils relate in such a way that increased the inductance, as each coil is in the return path of the other, with a mutually favorable orientation. This experiment below with two Strat single coils (Fender Pure Vintage 56), each of about 2.5H inductance, shows the same behavior, even when spaced apart in a typical pick guard. These pickup are no RW/RP, but flipping one of the pickups over is effectively the same, since the pole piece polarity doesn't matter (or at least it shouldn't).
When the coils are set to non RW/RP, the overall inductance is about 66mH higher compared to non RW/RP. The meter shows a capacitance of 266pF, which looks reasonable for two Strat pickups in parallel. 266pF plus a standard test load of 470pF comes out to 736pF. Based on that capacitance and these inductances the peak frequency is 5.295kHz non-RW/RP, and a lower 5.157kHz with RW/RP. A ~140Hz difference might be audible at lower frequencies, but at 5kHz, only the highest, shortest lived harmonics would be impacted, and it's unlikely the difference would be clearly perceived, let alone clearly remembered. If the single coils pickups had a much higher inductance, of say, 5 henries or greater, the difference in peak frequency might more plainly audible, but that would be a very uncommon scenario.
There are subjective observations from the web "You lose some high end in positions 2 and 4 with an RWRP middle", "You get more mids or thicker sound, without the RWRP.". It seems to me that the inductance factor, which is a real measurable difference, would still not account for a clearly audible difference. The first comment would correspond to an increase in inductance and a lower resonant peak, but the second comment would be contrary to the fact. I'm open to the possibility that there might be a cause for difference that hasn't been considered, but I don't see it at this moment.
The LCR meter shows a capacitance of 266pF with the two pickups in parallel.
As far as I know there is no clear reason why the two wiring modes should sound any different, aside from the lack of noise. One theory I saw that RW/RP might cancel microphonics as well as noise, and that the cancellation of microphonics might account for the difference, but that most likely doesn't happen. First, if this were the case, typical humbuckers would be averse to microphonics. Second, microphonics are just as likely caused by dynamic capacitances as grounded metal parts vibrate, and those voltages are not cancelled out by RW/RP coils, which is why humbuckers still feature shielding, despite the humbucking.
Another reason floated was that the RW/RP middle pickup will "push" on the strings while the neck and bridge pull at it, but it's obvious that the magnetic interaction between the magnets and strings are localized, and the guitar strings so magnetically unsubstantial, that the two outer magnetic fields will not impose any sort of repulsive force towards the middle.
Another possible reason they might sound different is a change in the parallel inductance. It's known that with a side-by-side humbucker, the coils relate in such a way that increased the inductance, as each coil is in the return path of the other, with a mutually favorable orientation. This experiment below with two Strat single coils (Fender Pure Vintage 56), each of about 2.5H inductance, shows the same behavior, even when spaced apart in a typical pick guard. These pickup are no RW/RP, but flipping one of the pickups over is effectively the same, since the pole piece polarity doesn't matter (or at least it shouldn't).
When the coils are set to non RW/RP, the overall inductance is about 66mH higher compared to non RW/RP. The meter shows a capacitance of 266pF, which looks reasonable for two Strat pickups in parallel. 266pF plus a standard test load of 470pF comes out to 736pF. Based on that capacitance and these inductances the peak frequency is 5.295kHz non-RW/RP, and a lower 5.157kHz with RW/RP. A ~140Hz difference might be audible at lower frequencies, but at 5kHz, only the highest, shortest lived harmonics would be impacted, and it's unlikely the difference would be clearly perceived, let alone clearly remembered. If the single coils pickups had a much higher inductance, of say, 5 henries or greater, the difference in peak frequency might more plainly audible, but that would be a very uncommon scenario.
There are subjective observations from the web "You lose some high end in positions 2 and 4 with an RWRP middle", "You get more mids or thicker sound, without the RWRP.". It seems to me that the inductance factor, which is a real measurable difference, would still not account for a clearly audible difference. The first comment would correspond to an increase in inductance and a lower resonant peak, but the second comment would be contrary to the fact. I'm open to the possibility that there might be a cause for difference that hasn't been considered, but I don't see it at this moment.
The LCR meter shows a capacitance of 266pF with the two pickups in parallel.
