Guitars are a really interesting piece of equipment when you look at them from a scientific perspective. There are many scientific principles at play to make a guitar function in the way that it does, one is electromagnetism, and the other could be piezoelectricity if you’ve chosen to use piezo pickups.
Upon learning of the electromagnetic effect of the guitar’s pickups, a lot of people ask whether guitar strings are actually magnetic, and whether they would function properly if they weren’t.
Guitar strings are slightly magnetic, especially when they’re nickel-plated or contain ferromagnetic elements like iron or nickel. Nickel, especially, is one of the rare metals that are ferromagnetic at room temperature, which is one of the reasons guitar string manufacturers use it.
While guitar strings are slightly magnetic, they’re not magnetically charged in the way that actual magnets are. For example, get your hands on a magnet and actually put it next to one of your guitar strings to see how they’ll respond. Guitar pickups, which are just magnets wrapped with thousands of core wire, necessitate slightly magnetic guitar strings, otherwise, they wouldn’t work.
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Why Guitar Strings Need to Be Slightly Magnetic
As most guitarists know, acoustic guitars and electric guitars are quite different from each other in both size, shape, color, sound, and construction. For one, an acoustic is just a giant, hollowed-out piece of wood that has strings on it. This is part of what makes an acoustic guitar an acoustic guitar.
The instrument produces sound via the vibrating strings which are transmitted to and then amplified by the sound-hole of the guitar. This is an important part of the process, and it’s also one of the reasons why the type of wood an acoustic guitar uses is so important compared to an electric guitar.
Electric guitars are not the same way, in fact, according to Explain That Stuff in their article that I highly recommend checking out here, George Beauchamp’s original patent says it didn’t matter what type of wood the musical instrument was constructed with. The material type wouldn’t push it away from the “spirit” of the original idea.
The Importance of Electromagnetism for Electric Guitars
After a guitarist strikes a guitar string, it creates electricity due to the magnetic coil wrapped in core wire – also called a pickup. The pickups underneath the strings create a magnetic field in which the guitar strings vibrate. The ferromagnetic guitar strings vibrate within the pickups’ magnetic field, becoming partially magnetized in the process.
Faraday’s Law states that a continuously changing magnetic field creates electricity. How this relates to the electric guitar is that the vibrating strings are constantly moving, therefore creating an electrical current that travels through the pickups and is then amplified by a loudspeaker, also known as an amp. This is all made possible by the electromagnetic effect of the pickups’ magnetic field, Faraday’s Law, and the ferromagnetism of the guitar strings.
In this scientific paper, how a guitar works and how the strings vibrate to create sound is explored once again. Take note of the one section, in particular, which states that guitar strings are typically ferromagnetic on account of either the nickel (Ni) or iron (Fe) in them. On an unrelated note, the heavy metals present in guitar strings aren’t toxic, as I explained here, so don’t worry.
What is Ferromagnetism?
Ferromagnetism, according to Wikipedia, is the process by which particular metals like iron become permanent magnets, or, in other words, become attracted to magnets. Ferromagnetism is the strongest type of magnetism and it’s the process that’s responsible for the magnetism of many household items that people use today including accessories like fridge magnets.
For a metal to be ferromagnetic, permanent magnets have to remain magnetized even after the surrounding magnetic field has been taken away. Materials that are ferromagnetic will remain partially responsive to other metals even after the magnetic field (another magnet or material) has been removed.
Whether the magnetic field has been removed or not isn’t that important when it comes to guitar strings. The reason for that is the simple: the electric guitar strings are always overtop of the pickups, which are what is producing the magnetic field.
What About Nylon Strings and Acoustic Guitar Strings? Are They Magnetic?
Nylon strings like D’Addario’s Pro Arté (on Amazon) are not ferromagnetic, because they’re made out of nylon, and not ferromagnetic materials such as nickel, iron, or steel. Acoustic guitar strings, on the other hand, are slightly ferromagnetic, but not as much as electric guitar strings because they’re typically coated with phosphor bronze rather than nickel or iron. Nickel and iron are more ferromagnetic than phosphor bronze.
Acoustic guitar strings like Elixirs (also from Amazon) need to be made from more acoustically resonant materials because there are no magnetic fields, coil wires, or electromagnetic principles used to amplify the sound. An acoustic guitar is just a big, hollowed out, piece of wood with a hole in it which acts as a loud speaker for the vibrating strings.
Nylon string and acoustic guitars work quite a bit differently compared to the electric guitar. Even the strings (more on that in this article) reflect this simple fact. The electric guitar, as it was noted already above a few times, utilizes several different scientific principles including electromagnetism and Faraday’s law, whereas acoustic guitars do not.
Acoustic guitars are called acoustic guitars, because the sound is amplified via air and space, rather than via electricity and magnetic fields. The same thing can also be said for nylon string guitars, and it’s one of the reasons why nylon string and acoustic guitars use completely different scientific principles in order to have their sounds amplified.
This is where piezoelectricity comes into play. One thing that’s worth mentioning right now is that it’s not (PIE-ZOH), it’s (PEE-YAY-ZOH). Now you don’t have to embarrass yourself the next time that you talk to someone about this.
Acoustic and Nylon String Acoustics Often Use Piezoelectricity Instead of Electromagnetism
Piezoelectricity, or “pee-YAY-Zoh”-electricity is a separate scientific principle that amplifies the sound of the strings via crystals, rather than electromagnetic fields, coil wires, and induction. It sounds like some insane voodoo or ridiculous pseudoscience, but it’s true. A good explanation of how piezoelectricity works is in the YouTube video below:
A barbecue lighter is a great way of explaining how piezoelectricity works because it’s an example of how pressure and tension work together with a piezoelectric crystal. As the video states, piezoelectricity is the scientific principle by which barbeque lighters work.
By applying a lot of pressure via blunt force to a magnetically charged material like a quartz crystal, you can actually create sparks (an electrical charge) that is then used to ignite butane. Barbecue lighters use a spring, a tiny hammer, and a piezoelectric crystal together in order to create fire.
By putting a lot of pressure on the button which loads the spring, the spring unleashes a ton of kinetic energy which then strikes against the piezoelectric crystal and sends a voltage up the lighter to produce a spark. If you take a look at the top of a barbecue lighter, you’ll notice there is a gap where the spark travels from one side of the steel capsule to the other.
This is actually done on purpose, because it gives the spark a chance to ignite the butane. When you press on the button, it sends a flammable gas up to the top of the lighter which is then ignited by the spark. This is the same mechanism by which acoustic and nylon string guitars use piezo pickups.
The piezoelectric effect is a term that’s used to describe the discovery made by scientists whereby certain naturally occurring substances like quartz, for example, are capable of producing electrical currents and voltage by having pressure or mechanical stress applied to them.
For example, you can create an electrical charge by slamming a piece of quartz with a hammer. As CSGuitars puts it in this video, while we can’t squeeze blood from a stone, you can squeeze electricity out of it. Interestingly, scientists have figured out a way to create electrical charges by implementing the piezoelectrical effect via transducers.
In other words, there are transducers where you can literally just squeeze it and it’ll produce an electrical charge. If you put one of these transducers underneath the bridge of a guitar and then strum the strings of the guitar, you can see that the vibrations from the strings actually change the voltage within the transducer, creating an electrical current and allowing the acoustic/nylon string to be amplified.
In other words, the piezoelectric transducer like KNA’s NG-1 (which can be found on Amazon as well) is capable of turning the vibrations of the strings into an audio signal which can then be amplified by a guitar amp. To simplify it, nylon and acoustic guitars commonly use the piezoelectric effect rather than an electromagnetic effect in order to amplify their strings’ vibrations.
YouTube Video Tutorial
All of the links down below take you to Amazon
1) D’Addario’s Pro Arté Nylon Strings
2) Elixir’s 11-52 Acoustic Guitar Strings