Decoding Sound: A Comprehensive Guide to Headphone Technology

Whether we're enjoying music, audiobooks, or TikTok, headphones have become an essential modern accessory to our daily lives.

The ubiquitous demand for headphones means that there are many different kinds available, including (but not limited to) over ear headphones, studio headphones, in-ear headphones, wireless headphones, open headphones, and closed headphones .

Various types of headphones incorporate distinct technologies; for example, noise-cancelling headphones integrate additional technology to reduce ambient noise, adding an extra layer to the headphone experience.

In essence, headphones operate on a principle similar to speakers and the reverse of microphones—they convert electrical energy into sound by utilising magnets to vibrate the air, creating audible sound waves.

Digital audio, which is represented by 1’s and 0’s, is stored within a device, and when the playback is initiated, these digital data are processed through a digital-to-analog converter (DAC), transforming them into electrical signals.

These signals then traverse the headphone wires and reach the headphones themselves - and this is how headphones produce sound. 

The Driver Unit

Inside the headphones, the electrical signal encounters a driver unit, which can be of several types: dynamic, planar magnetic, electrostatic, or balanced armature. The driver comprises a permanent magnet, electromagnetic coils, and a diaphragm. The crux of headphone functionality effectively revolves around the utilisation of magnets—two in each earcup. One remains static (sometimes referred to as ‘permanent’), while the other, an electromagnet, oscillates. When the electrical signal reaches the earcup, it activates the electromagnet, which rapidly alternates its polarity in sync with the incoming sound pattern. This polarity shift causes the electromagnet to vibrate, interacting with the stationary magnet. These vibrating electromagnets are linked to a diaphragm, a thin membrane. As the electromagnet vibrates, so does the diaphragm, initiating air vibrations, commonly known as sound.

Dynamic Driver Unit

The dynamic driver unit operates through three primary components: a permanent magnet, electromagnetic coils, and a diaphragm. The fundamental aspect of headphone functionality centres around the utilisation of magnets, with two present in each ear cup. One remains fixed (permanent), while the other, an electromagnet, is mobile. Upon receiving the electrical signal in the earcup, it is directed to the electromagnet. This component swiftly alternates its polarity based on the pattern of the signal or the sounds being reproduced. The polarity shift causes rapid attraction and repulsion between the electromagnet and the permanent magnet, inducing vibrations. These vibrating electromagnets are linked to a diaphragm, a thin membrane. As the electromagnet vibrates, the diaphragm follows suit, initiating air vibrations—what we perceive as sound. Distinct frequencies vibrate at varying rates; hence, the electromagnet adjusts its vibrations accordingly to produce high or low tones. Adjusting the volume intensifies or diminishes these vibrations, impacting the intensity of the air's vibration.

Planar Magnetic Driver Unit

The planar magnetic driver unit operates in a manner akin to the dynamic driver unit, yet with notable distinctions. Instead of employing magnets to mobilise an electromagnetic coil, extremely thin magnetic conductors resembling miniature wires are distributed across the diaphragm. Unlike the single permanent magnet used in dynamic drivers, an array of magnets is positioned behind the diaphragm to facilitate proper responsiveness when an electrical current passes through the conductors. As the electrical current traverses the conductors, inducing a change in polarity, the diaphragm engages with the permanent magnets, leading to vibrations and the generation of sound. This type of driver unit is sometimes referred to as the Orthodynamic driver, a term coined by the Yamaha marketing team.

Electrostatic Driver Unit

Another common variant of drivers is the electrostatic driver unit, which is renowned for its association with some of the most esteemed headphones ever manufactured.

A distinctive feature of electrostatic headphones, setting them apart from other types, is that instead of utilising magnets to move the diaphragm, the diaphragm itself is the moving component. In electrostatic headphones, the diaphragm is crafted from an exceedingly thin sheet of electrically charged material, positioned between two conductive plates—one positively charged and the other negatively charged. When electrical charges course through these plates, the electrically charged film oscillates, influencing the surrounding air and producing sound. Some enthusiasts posit that electrostatic headphones deliver superior sound due to the exceptionally thin and lightweight nature of the electrically charged film. Unlike dynamic or planar magnetic headphones, it is believed that electrostatic headphones do not impart the same coloration to the sound. However, it's worth noting that electrostatic headphones often come with a substantial price tag, frequently reaching multiple thousands of dollars.

Balanced Armature Drivers

A balanced armature driver, often referred to as balanced armatures (BAs), is a distinctive type of transducer that is utilised in certain headphones and in-ear monitors. Operating on the principle of electromagnetic induction, these drivers feature a miniature armature suspended between two magnets. As an electrical current courses through the armature's coil, it moves back and forth between the magnets, producing sound. Notably compact in size, balanced armature drivers are favoured for their efficiency, making them particularly suitable for in-ear applications where space is at a premium. Their precision in delivering accurate and detailed sound, particularly in the mid to high-frequency ranges, has earned them acclaim in the realms of music monitoring and audiophile-grade audio equipment. However, their bass response is sometimes perceived as limited compared to dynamic drivers, prompting some IEM designs to incorporate a combination of both driver types for a more balanced sonic profile. Commonly found in professional monitoring equipment and hearing aids, balanced armature drivers continue to be valued for their compact design and high-fidelity audio reproduction.

In-Ear Headphones: Compact and portable, in-ear headphones fit snugly into the ear canal, providing a lightweight and discreet audio solution ideal for on-the-go use.

Studio Headphones: Designed for audio professionals and enthusiasts, studio headphones deliver accurate and detailed sound reproduction, often with a flat frequency response for critical monitoring during music production.

Wireless Headphones: Offering the freedom of movement without tangled wires, wireless headphones use Bluetooth technology to connect to devices, providing a convenient and cable-free listening experience.

Over-Ear Headphones: With larger ear cups that enclose the ears, over-ear headphones provide immersive sound and typically offer better noise isolation, making them suitable for extended listening sessions.

Noise-Cancelling Headphones: Equipped with technology that actively reduces ambient noise, noise-cancelling headphones are ideal for creating a quiet listening environment in noisy surroundings, such as during travel.

Sports and Fitness Headphones: Designed for active lifestyles, sports headphones are often sweat-resistant and feature a secure fit to stay in place during physical activities like running or working out.

Gaming Headphones: Tailored for gamers, gaming headphones often feature surround sound capabilities and a built-in microphone, enhancing the gaming experience with immersive audio and clear communication.

Consider the following key factors when selecting your next pair of headphones…

What do you need them for?

First things first, you should have a think about how you plan to use your headphones. Whether it's for jogging without worrying about them falling off, or enjoying quiet moments on a crowded plane, your usage scenario should determine (or at the very least, narrow down) your choice among the various types available.

Headphone Type

Next, it’s time to consider the whistle and bells. You can choose between the reliability of a wired connection, ensuring a consistently strong signal, or the freedom of wireless, allowing you to move unrestrictedly. Many wireless models also come with a wired option for versatile use. You’ll also need to decide between closed headphones, which offer a sealed environment for an immersive experience, and open headphones, which allows your music to interact with the surrounding environment for a more natural sound. There are no wrong answers here, this is very much a personal preference. 

Reputable Brand & Authorised Dealer

Are the headphones from a trustworthy brand with a proven track record? Brands that undergo rigorous testing and evaluation can provide assurance of quality and performance. Similarly, purchasing your headphones from an authorised dealer helps ensure authenticity and reliability. Acquiring the manufacturer's warranty, service, and support further safeguards your investment, ensuring assistance long after the purchase. 

Whether you’re after headphones ​for immersive studio sessions, on-the-go adventures, or both, MiniDisc will be able to help set you up with the perfect match for your optimal audio enjoyment. You can head over to the MiniDisc website to browse a wide range of high quality headphones. Can’t find what you’re looking for? Don’t be afraid to get in touch with us directly via the MiniDisc Contact Us page.