Guitar Pickup Polarity: What Reverse Wound Means

Magnet polarity and winding direction

Every magnetic pickup contains a bar magnet with a north and a south pole, and a coil of wire wound around it. The magnet's orientation, meaning which pole faces the strings, is one part of the pickup's polarity. The other part is the winding direction: the coil is wound clockwise or counterclockwise when viewed from the top. These two factors together determine the electrical phase of the pickup's output signal relative to another pickup. For more on how pickups are arranged in a guitar, see pickup configurations.

When a guitar has two pickups with identical magnet orientation and identical winding direction, they produce signals that are in phase with each other for a given string vibration. If one pickup is reversed in both respects, the string signal becomes inverted twice, returning to the same phase as the other pickup. This doubling of reversal is the key to hum cancellation.

How reverse winding cancels hum

Single-coil pickups are susceptible to electromagnetic interference from power lines, transformers, and other electrical sources. This interference induces a hum in the coil. The hum voltage is independent of the magnet's pole direction; it enters the coil simply because the coil is a loop of wire in a changing magnetic field. As a result, the hum appears identically in two pickups that are side by side, regardless of their magnet orientation. Understanding the difference between single-coils and humbuckers helps, so read single-coil vs humbucker.

Now consider a pair of pickups where one is wound counterclockwise and has the opposite magnet pole up. When both are selected, the string signal from the reversed pickup is inverted twice, so it aligns with the normal pickup's signal. The hum, however, is not affected by the magnet reversal. It is inverted by the winding reversal only, placing it 180 degrees out of phase with the hum from the other pickup. When the two signals are summed, the hum cancels and the string signal remains strong.

This principle is the same one used in some acoustic guitar preamps. For example, Martin's E1 electronics include a phase switch that reverses the signal 180 degrees to reduce feedback and increase bass response. While the acoustic preamp phase control is a user switch, electric guitar pickups achieve a similar effect permanently through internal winding and magnet orientation.

• The magnet's pole orientation determines the polarity of the string signal.
• The coil winding direction determines the polarity of both the string signal and the hum.
• Reversing both restores the string signal while flipping the hum, so the hum cancels when two pickups are on.

Why single-coils hum and how RWRP solves it

A single-coil pickup is essentially a wire coil with a magnet. The coil picks up the string's magnetic field changes, but it also acts as an antenna for electromagnetic noise. This is why a traditional Stratocaster in positions 1, 3, or 5 often produces a 60-cycle hum. The hum is most noticeable when you are not touching the strings and can be reduced by shielding, as explained in electric guitar shielding, but the classic solution is to pair a normal-wound pickup with a reverse-wound, reverse-polarity (RWRP) pickup.

When you select the middle and bridge pickups together, or the neck and middle pickups together, the two pickups are connected in parallel. The hum from each pickup is out of phase and cancels, leaving a cleaner signal. This is why many Strat-style guitars come with a reverse-wound middle pickup from the factory. It turns the 2 and 4 positions into hum-canceling combinations without adding any extra circuitry or humbuckers.

What to look for in a new guitar

If you want the quiet middle positions on a single-coil guitar, check the pickup specifications for a note like "RWRP" or "reverse wound/reverse polarity" on the middle pickup. This is common on many production guitars, but not universal. If you are buying a guitar with two or three single-coils, confirm that at least one pickup is reverse wound if you want hum-free combinations. Our best electric guitars guide highlights models with this feature.

For players who prefer humbuckers, note that a humbucker is itself a pair of reverse-wound, reverse-polarity coils inside a single housing. The same principle applies, but you do not have to worry about selecting two separate pickups. Guitars with coil-splitting can turn a humbucker into a single-coil sound, but the hum may return if the split leaves only one coil active. If you're on a budget, check the mid-range electric guitars for humbucker options.

When shopping for a new electric guitar, consider how you plan to use the pickup selector. If you often play in positions 2 and 4 on a three-pickup guitar, a reverse-wound middle pickup is a valuable feature. Browse our electric guitar recommendations to find models that list this specification.

How to identify reverse-wound pickups

Pickup manufacturers often mark the lead wires or the pickup base plate with colored wires and labels. A common convention is that red or white wires indicate the hot lead, while black is ground. The winding direction and magnet orientation are not always marked, but many aftermarket pickups include documentation. If you are unsure, you can test the phase relationship by tapping the pickup with a screwdriver while the guitar is through an amp, but this is more about experimentation than precise measurement.

For a new guitar, the easiest path is to read the product description. Many brands explicitly state "reverse wound middle pickup" or "RWRP" in the spec list. If the description does not mention it, you can contact the manufacturer or retailer. For vintage-style guitars, aftermarket pickup sets usually include an RWRP middle pickup as a standard pairing. If you're considering upgrading, see our guide on how to upgrade electric guitar pickups.

• Check the pickup's spec sheet for RWRP or reverse polarity.
• Look for wire color coding that follows standard conventions.
• Ask the seller or manufacturer if the product page is unclear.

Common misconceptions about polarity

A common misunderstanding is that reversing the winding alone cancels hum. That is not true: reversing only the winding flips the string signal too, so the two pickups would be out of phase and produce a thin, hollow sound. The magnet must also be reversed to bring the string signal back in phase. Only the combination of both reversals cancels hum without killing the signal.

Another myth is that reverse-wound pickups sound different. In fact, the tonal effect is neutral; the pickup uses the same magnet and wire as a standard unit. The difference appears only when two pickups are combined. If you install a reverse-wound pickup as the sole pickup, it will produce the same tone as a normal pickup of identical construction.

What to pick for your use

Questions

What exactly does 'reverse wound' mean on a pickup?

It means the coil is wound in the opposite direction compared to a standard pickup of the same type. Combined with a reversed magnet pole, it creates an out-of-phase hum signal while keeping the string signal in phase when paired with a normal pickup.

Is a reverse-wound pickup different in tone?

No. The magnet, wire, and number of turns are the same. The only difference is the orientation of the wind and the magnet, which has no effect on the isolated pickup's sound.

Can I add a reverse-wound pickup to an existing guitar?

Yes. Many aftermarket pickup sets include a reverse-wound middle pickup. You can also custom-order a pickup with the same specifications but reversed polarity. Installation requires basic soldering, and we have a guide on upgrading electric guitar pickups that covers the process.

Why do some guitars have a reverse-wound middle pickup but not the neck or bridge?

On a three-pickup guitar, the middle pickup is the one selected together with either the neck or bridge in positions 2 and 4. A single RWRP middle pickup provides hum cancellation in both combinations, so manufacturers only need to reverse one pickup.

Does a humbucker use the same principle?

Yes. A humbucker is essentially two single-coil pickups mounted side by side, one with opposite winding and magnet polarity. The two coils are connected in series, canceling hum while preserving the string signal.

Can I check pickup polarity with a multimeter?

You can measure DC resistance, but polarity is about phase, not resistance. To test polarity you would need to compare the output of two pickups using an oscilloscope or a simple pickup tester, which is beyond the scope of this article.