Headphones are a type of portable speaker that, along with earphones and buds, have become synonymous with our technological experience.
They blast our favorite music, allow us to listen to the latest podcasts without disturbing the rest of the subway, and allow for some crazy 8D sound experiences. But how do headphones work?
The answer is that, while they are technological marvels with teams of people working to improve the technology on a daily basis, they are essentially just tiny speakers that take electrical signals and transform them through a voice coil into Jack Johnson’s sweet tunes.
VIDEOS: How Do Headphones Work?
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HEADPHONES ARE BASICALLY JUST TINY LOUDSPEAKERS
To comprehend the inner workings of your headphones, consider them to be small-scale loudspeakers. Their goal is the same: to convert electrical signals into corresponding sound waves.
However, it is a little more complicated than that; the engineers who design these tiny little speakers must consider the speaker’s close proximity to the ear. This necessitates much lower input levels; we’re talking milliwatts here, not watts.
The size is the primary distinction between your loudspeakers and your headphones. Unlike loudspeakers, which must produce sound for rooms, halls, and open-air concerts, headphones should only produce enough sound for your ears.
So, while they are very similar, smaller versions of the same thing, the technology required to make them do what they do differ slightly.
There is a minor distinction between loudspeakers and headphones in terms of protective casing. The purpose of the loudspeaker box (or enclosure) is to amplify the sound and protect the speaker. Similarly, the “cover” of your headphones is designed to amplify, protect, and fit.
These are wearables, and comfort is in high demand. Loudspeakers typically have openings at the front and back to allow free movement of air, which produces the best sound. There are two types of headphones: closed-back and open-back.
Open-back speakers produce the best sound and are commonly used in recording studios. They can, however, be less discrete. Someone who wants to listen in private should opt for noise-canceling headphones with a closed back.
WHAT ARE THE MAJOR HEADPHONE COMPONENTS?
There are three very important components in your headphones. Different types of headphones may have additional bits and pieces, but without these three, no sound is ever coming out:
1. The Magnet
Magnets form the basis of your headphones. The coil is moved by two tiny magnets, one fixed and one electromagnet that moves. This movement is primarily responsible for the production of sound.
2. The Coil of the Voice
Electrical signals are fed into the coil, causing it to become more or less magnetic depending on the current. The coil is then attached to the diaphragm (imagine your own diaphragm, which allows air to move in and out of your lungs), and as the coil moves, so does the diaphragm.
3. The Diaphragm
The diaphragm is a thin, semi-rigid membrane that is attached to the coil. When the coil moves, the diaphragm moves, creating vibrations and producing sound.
Housed inside the driver assembly, these three parts are responsible for generating the sound. Understanding exactly how the driver works can be complicated.
HOW DO HEADPHONE DRIVERS WORK?
The driver serves as the operation’s central processing unit. When an electrical signal travels through the cord and into your headphones, it first arrives at the driver unit. In headphones, there are three main types of drivers:
- Driver with dynamism
- Magnetic planar driver
- Driver by electrostatic attraction
The dynamic driver is the most commonly used driver in headphones.
1. Dynamic Driver Unit (Moving Coil Drivers)
The dynamic driver unit is one of the most common and least expensive types of driver. It operates with three major components: a permanent magnet, an electromagnetic coil, and a diaphragm. The dynamic driver unit generates movement through electromagnetism and magnetism, which results in sound.
The coil becomes an electromagnet when it is magnetized by the fixed neodymium magnet. The coil generates a magnetic field after receiving electrical signals from the audio file. The magnet’s push and pull are determined by the flow of current.
This causes rapid backward and forward movement, which pushes and pulls on the diaphragm to which the coil is attached. Sound is produced when the air around the diaphragm is displaced. The louder the sound, the more air that is displaced.
Because of the friction created, dynamic driver units are excellent for producing bass sounds. However, there are some disadvantages. For one thing, audio is prone to distortion. This can be fixed with great engineering, as it is often found in high-quality headphones.
2. Planar Magnetic Driver Unit
While the planar magnetic driver unit is very similar to the dynamic driver unit in many ways, there are some significant differences. To begin with, rather than using magnets to move the coil, wiry magnetic conductors cover one side of the diaphragm.
Furthermore, an array of magnets hidden behind the diaphragm is used to detect electrical current as it flows through the conductors. The magnetic field changes as the electrical signal moves in and out of the conductors, causing the diaphragm to interact with the magnets, causing vibration and, eventually, sound.
These drivers are typically found in high-end open-back headphones. The diaphragm is frequently larger and heavier due to the multiple magnets. These aren’t your typical jogging headphones. They produce clear sounds with almost no distortion and good bass response at home or in a recording studio.
3. Electrostatic Driver Unit
Finally, we have the electrostatic driver unit, which is often considered the holy grail of headphone driver units due to its impressive technology. Whereas in other drivers, magnets move the coils, which causes the diaphragm to move, the diaphragm itself moves in this driver.
The diaphragm is made of an electrically charged thin sheet sandwiched between two oppositely charged conductive plates. The electrically charged diaphragm vibrates as the electrical signal passes through the plates, displacing air and producing sound.
Because the technology that powers this driver is limited, it also comes at a high cost. They are mostly used by professionals and are better suited for occasional use in a studio.
However, the sound quality is incredible, and we can only hope that, as with all technological advancements, this will soon be the future of all headphones.
HOW DO IN-EAR HEADPHONES (OR EARBUDS) WORK?
These tiny buds function in much the same way as headphones, with the main difference being their size. All of the same components are present, but they are much smaller, which is understandable given that everything must fit into your ear.
What’s great about earbuds is that even if the components aren’t of the highest quality, you don’t need to produce a lot of sounds because it’s only traveling the length of your ear canal. They are typically teardrop-shaped, allowing for a snug fit in the ear.
The sound is usually clear, and any external noises are muffled by the earbud. Most earbuds have a hard plastic casing and are classified as closed-back earphones. Some may have vent holes that allow some outside noise in.
The mechanism is very similar to that of the larger headphones. An electrical charge is transmitted through the cord to the driver.
The coil in the driver becomes magnetized and moves in response to the magnetic pull and push of the signal. As the coil moves, it pulls on the diaphragm, causing sound waves to be produced.
Because of their small size, earphones are easier to transport than headphones. Though headphones provide better sound, earphones clearly win in terms of convenience. It’s simple to toss into a bag and pull out when needed.
When it comes to comfort, headphones frequently outperform. Earphones, despite their small size, do not always fit your ear. Fortunately, there are hundreds of designs to choose from, and you will eventually find your perfect fit.
HOW DO OVER-EAR AND ON-EAR HEADPHONES WORK?
Now that you have an idea of how loudspeakers work, you can apply that knowledge to over-ear headphones. While we don’t recommend trying this at home, we’ll quickly put on a pair of headphones and walk you through each step.
When it comes to headphones, the first thing you notice is the headset and the poofy ear covers. They’re beautiful, but that’s not where the magic happens. By removing the pads, you gain access to the inner workings of your headphones.
Everything is contained within the headphone (both over and on-ear) enclosure, including the driver and battery. As we discussed earlier in this post, the diaphragm is the main component that generates sound. The diaphragm can also resemble a cone, which is why it’s called a cone.
Sound is produced as the diaphragm is pushed and pulled. Depending on the driver unit, the pushing and pulling action can be produced in a variety of ways.
There are two units that provide the best sound quality. The Planar Magnetic Driver Unit is a more advanced version of the traditional dynamic driver unit. Instead of magnets, this rectangular-shaped driver unit contains an electric conductor-covered diaphragm.
This is then pushed and pulled by an array of magnets surrounding it. The diaphragm receives the electric signal, which causes it to change charge and vibrate. Genius.
The Electrostatic Driver Unit is a close second. This small powerhouse has the most distinctive design on the market. The diaphragm is as light as air and is made of an electrically charged material.
The diaphragm is sandwiched between two perforated metal plates, and when an audio signal is directed to these plates, a magnetic pull occurs, causing the diaphragm to vibrate uniformly. Of all the drivers, this produces the smoothest sound with the least distortion.
When you listen to music through your earphones, it’s all about electric signals, magnets, vibrations, and displaced air to get you to the sweet sounds you want to hear.
HOW DO OPEN-BACK HEADPHONES WORK?
Open-back headphones have the same inner workings as normal headphones, but the difference comes in with the casing. Instead of being a closed unit, the unit is open on both sides, allowing for free flow of air and improved sound and acoustics.
This design prioritizes quality and is frequently more comfortable. It’s an excellent choice for those who work with sound and must wear headphones for extended periods of time. Comb filtering is not possible due to the open back (sound engineers sing hallelujah).
For greater comfort, open-back chairs typically have larger cushions. The back of the headset is open, which prevents comb filtering and allows sound to travel both ways easily and normally with little isolation, while the headband applies very little pressure to your head.
While they provide all of these additional benefits, they are often much lighter than cheaper models due to the use of higher-quality materials.
One of the disadvantages of open-back headphones is that noise cancellation is nearly impossible, making them unsuitable for use in noisy environments. Next, if you’re a recording artist, some of the noise may bleed into your mic if you turn it up too loud.
HOW DO NOISE-CANCELING HEADPHONES WORK?
We all know about the wonders of noise-canceling headphones, but how exactly do they work?
First of all, we need to understand there are different levels of noise-canceling tech out there. Essentially, there are two types: passive and active.
1. Passive Noise-Canceling Headphones
These are similar to earmuffs in that they act as a physical barrier, preventing any external sounds from reaching your ears.
2. Headphones with Active Noise Cancellation
While still providing a physical barrier (improved to eliminate specific high-pitched sounds), active noise-canceling uses technology to allow your microphone to pick up any low-frequency noises and neutralize them before they reach your ear. I know, it’s incredible.
HOW DO WIRELESS HEADPHONES WORK?
Wireless headphones are fantastic because they provide complete freedom – but how do they work? The mechanics of how the sound is produced are essentially the same, but how does the electric signal reach the driver unit?
Modern wireless technology enters the picture – the audio signal is actually transmitted via wireless technology such as Bluetooth, radio frequency (RF), or infrared (IR).
HOW DO BLUETOOTH HEADPHONES WORK?
Bluetooth headphones can play music wirelessly. They communicate with Bluetooth-enabled audio devices via radio waves. Bluetooth Headphones can be used with your smartphone or any other smart device. Bluetooth headsets can detect radio waves from up to 50 meters away.
You will be able to pick up the Bluetooth headphones as soon as you turn on the Bluetooth on your smart device. The headsets must be in a discoverable mode to enable the pair function, but once paired, you will not have to do so again.
To pair successfully, you may need to enter a password; this can be found in your user manual or in your Bluetooth settings on your smart device. Surprisingly, Bluetooth devices typically connect via a license-free 2.4 GHz radio band.
HOW DO RF HEADPHONES WORK?
RF headphones function similarly to Bluetooth headphones, with the main difference being that they transmit at different frequencies. RF headphones use frequencies ranging from 900MHz to 3.2GHz. You’ll be able to pick up the frequency with RF Headphones at around 90 meters.
It is simple to use; simply connect the transmitter to your smart device via the AC adapter and turn it on. The RF headphones and transmitter should automatically pair. Once the devices are paired, the transmitter should illuminate with a blue light.
RF headphones are typically best suited for use with televisions; simply plug in the adapter and forget about it. Ideal for gamers and late-night binges.
HOW DO THE HEADPHONE WIRES WORK?
Headphone wires are not something we often think about, but neatly encased in protective rubber lies 6 wires, all essential in carrying your sound waves to your ears.
The six wires that connect to your TRRS jack are:
- Right audio (red)
- Right audio ground (green)
- Left audio (blue)
- Left audio ground (green)
- Microphone (yellow)
- Microphone ground (green)
A synthetic core is added between the wires to strengthen the cord. Headphone cables have come a long way, as evidenced by the cables. Your headphones have cables that power a control panel that allows you to play, pause, change tracks, and adjust the volume.
There are several types of headphone cables available on the market, including:
- Optical cables: Some cables are made of optic fiberglass for extra-fast transmission.
- Regular cables are made of ordinary copper wire that has been wrapped in protective plastic material. These are the most typical.
- Flat tangle-free cables: These cables, which are also made of copper and covered in protective plastic, are flattened to prevent tangling.
- Coaxial cables have a copper core, a plastic cover for insulation, and an additional fabric covering. Extremely long-lasting and high-performing.
- Fabric braided cables: These are hybrid cables that use different materials for conduction and insulation. They are high quality and long-lasting.
Headphones are becoming increasingly technical, and this trend is likely to continue; however, the fundamentals of how sound works will largely remain unchanged. If you have any questions about how headphones work, please leave them in the comments section.
FAQs On How Headphones Work
What is the science behind headphones?
When an electrical signal from a song or podcast pulses through the wires in a pair of headphones, the current changes, and the magnet moves.
How do headphones function with this phone?
Headphones function primarily in the same way that speakers do. They use vibrating magnets to convert electrical energy into sound. These magnets then create sound by vibrating the air around them.
How do earphones work in terms of sound physics?
The diaphragm sits between two perforated metal plates or electrodes. The current flowing through the electrodes creates an electric field, which causes the diaphragm to move between the plates.
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