Without headphone drivers, you can't hear any sounds coming from a headphone. It is one of the vital components of a headphone that converts electrical signals to sound waves that you can easily hear. But there is more than one kind of driver inside a headphone.
The types of drivers vary in size from as small as 8mm to as large as 50mm. But the size does not dictate the efficiency of a headphone driver. It's the technology used that makes some drivers better than others. Some headphones may also have multiple drivers to manage a variety of frequencies
- 1 What is a headphone driver?
- 2 The headphone driver types list
- 3 Balanced Armature Drivers
- 4 Dynamic Driver
- 5 Electrostatic drivers
- 6 Planar magnetic drivers
- 7 Magnetostriction of the bone conduction driver
- 8 FAQ
- 9 Wrap Up
What is a headphone driver?
What are drivers in headphones? A headphone driver is a simple speaker that moves air. As air is driven into the speaker, pressure waves are created which results in sounds that pass through the ear structures. A driver is one of the most important components in a headphone or speaker which changes electrical energy to sound energy. Drivers are also known as transducers or motors and are a crucial component of headphones and loudspeakers.
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The headphone driver types list
Aside from size, drivers also vary in their core technologies. Each kind has a special way of creating a sound which explains the many different types of audio output systems. Let's find out more about the five different kinds of drivers present in headphones.
Remember the following kinds of headphone drivers:
- Balanced armature
- Dynamic or the moving coil driver
- Electrostatic drivers
- Planar magnetic drivers
- Magnetostriction of the bone conduction driver
Balanced Armature Drivers
Of the five types of headphone drivers, the balanced armature driver is the smallest. This type is commonly used in in-ear devices as well as hearing aids. The name of this driver says it all: it has a magnetic armature that is on top of a pivot. This rotates and moves between the two magnets.
When the armature is at the center of the magnetic field, there is zero net force acting on it. This is the point when the magnetic armature is balanced. As an electric current is fired to the coil around the armature, the force created will move the armature. When this happens, the diaphragm also moves and produces sound.
What a balanced armature driver does to sound
Despite the needed amount of force to keep the armature balanced, this is still an easy and efficient technology. Some headphones use many armature drivers like the 1MORE Triple-Driver, an in-ear headphone device. With multiple armature drivers, there is a specific range of frequency for every component: a driver handles the bases, while others work using specific frequencies.
Balanced armature drivers are very efficient despite their size and produce amazing treble responses. However, balanced armature drivers are the most expensive. When balanced armature vs dynamic driver, balanced armature headphones are very costly.
Dynamic drivers are very common in everyday use headphones. The driver is fixed, made from very durable, powerful neodymium which is needed to produce a static magnetic field A dynamic driver will work with electric currents passing through the voice coil and moves in a back and forth manner. This component moves according to the signal it receives. The coil is connected to a thin membrane that amplifies all vibrations which is the sounds that you hear from a headphone
Dynamic drivers are very affordable which is why it’s used in traditional, cheap headphones. The component is lightweight and very compact and is very durable even when the headphones are frequently used. However, dynamic drivers are unable to produce the best sounds
What dynamic driver does to sound?
The basic technology behind headphones has not changed for decades but has been greatly improved. Nowadays, dynamic drivers are able to produce better sounds but may still suffer to limited bandwidths because of factors like distortion, resonance, and power compression. Also, the sound quality delivered by dynamic drivers may vary according to the type of headphone materials.
Despite these drawbacks, dynamic drivers are much easier to use and will not need an external amplifier to produce the best feedback sounds.
Electrostatic drivers function using a different technology compared to regular dynamic drivers. Electrostatics work by placing static electrical charges on a very thin film that’s located between two metal plates. As the signals pass through the plates, the film will move back and forth because of the natural electrical movements of attraction and then, repulsion. This is the same thing that happens in a condenser microphone but is done in reverse.
Electrostatic drivers are common in high-end headphones. These are expensive compared to dynamic drivers and will need a dedicated amplifier. This additional requirement adds to the cost of using this kind of headphone.
What do electrostatic drivers do to the sound?
The very thin membrane or diaphragm does not store or keep energy and has zero tolerance therefore it's free from distortion common in moving coil-type headphones and speakers. This technology is very accurate but is not practical to develop which is why electrostatic driver devices are only common in professional-quality audio equipment.
Planar magnetic drivers
What are planar magnetic headphones? Another name for planar magnetic drivers is orthodynamic drivers. Created by Yamaha, it is the technology used in over-the-ear headphones with an open-back design. Planar magnetic drivers are very thin and are common in expensive, professional-quality headphones.
Planar drivers work using the same principle as a dynamic driver which uses magnetic fields to create sounds. But instead of the voice coil moving back and forth a flat membrane, the diaphragm is moved by the magnetic field to produce different kinds of sounds.
However, the membrane must be evenly vibrated using larger magnets or by using multiple magnets. More components increase the overall weight and bulkiness of the headphone. You may also need to use an external amplifier to improve overall power and output.
What do planar magnetic drivers do to the sound?
Planar magnetic drivers create better, professional-sounding audio with no distortion, good bass response, and high transient response. However, there are some drawbacks. When it comes to planar magnetic headphones vs dynamic, planar magnetic models are heavier, bulkier, and not as compact and portable compared to headphones with a dynamic driver. Planar magnetic headphones are also more expensive.
Meanwhile, tech companies such as Oppo have developed planar magnetic headphones to solve some of these drawbacks. The Oppo PM 1 is a lightweight, low impedance headphone that’s just 395 grams which is just a small fraction of other planar magnetic models.
Magnetostriction of the bone conduction driver
A new headphone driver design called the magnetostriction driver bypasses the eardrum. It works by directing the vibrations to the inner ear through the bones of the skull. Also called bone conduction drivers, this technology is helpful if you need to keep your ears unobstructed during an activity.
A magnetostriction headphone helps people who are hard at hearing as sounds are sent through the bone structure. This kind will work underwater and thus are more efficient and more versatile than regular headphone drivers.
What do magnetostriction drivers do to the sound?
This type of driver makes sounds clearer and louder especially for people who need help with hearing and those who need to work or move with their ears unobstructed. However, sounds may not be as pure as regular headphones.
The cost of magnetostriction driver headphones will vary depending on their construction, components, and use. Those used for regular activities like jogging, running, and working out are more affordable than those developed for people with hearing loss.
Related: Harman Curve for Headphones
The following are frequently asked questions and their corresponding answers about headphone drivers
- Are there drivers for speakers?
Just like headphones, speakers have drivers. These are vibrating components that produce sounds that you hear. There are many types of drivers and almost all move air to make sounds.
- Which type of headphone driver is the best?
The best type of headphone driver depends on your needs. If you need in-ear monitors or hearing aids, a balanced armature driver is best but if you need a traditional headphone then a dynamic driver headphone is a good choice.
- Are bigger headphone drivers better than smaller drivers?
Indeed, bigger headphone drivers are capable of producing higher audio output but this does not mean that these can provide better sounds. In the case of 40mm drivers vs 50mm drivers, these are often used as headphone drivers. If you’re looking for the best driver, size should just be one of the factors to consider.
- Are 10mm headphone drivers better?
The ideal driver size will depend on the headphone design and not the size. 8 to 15mm diameter drivers are for earphones while 20 to 50mm drivers are for headphones.
Headphone drivers are crucial components of headphones and speakers. The type of driver determines the sound quality and the headphone use. Regular headphones and commercially available headphones use planar drivers. These may not be the best drivers but are the most affordable and are available in different styles and designs. Other types are for professional use and thus are more expensive than conventional headphones.
Graduated with a Bachelor of Audio Engineering and Sound Production. He has worked with a number of studios as a Recording Engineer, with over 10 years of servicing experience in both re-recording mixing and sound editing.