How Do Planar Magnetic Headphone Drivers Work?
Headphone drivers are arguably the most important component of any audio product, and if you want to dive into the world of headphones it’s important to know all of the different drivers and how they can influence the sound that an audio products puts out.
This article is part of our series on headphones and headphone drivers. You can always check out our overarching article on headphone drivers in case you’re interested.
What are Planar Magnetic Drivers?
Audio drivers need to find a way to ‘set the air in motion’ (this is incredibly simplified) and create sound waves, and they do this by vibrating a thin and flat piece of material in accordance with the audio signal that it receives. Generally, drivers do this by applying an electric signal (i.e. an audio signal) to a coil of wire inside the driver that’s connected to a diaphragm that sits in between magnets, thus making it electromagnetic. This then causes a push/pull interaction between the coil and the magnets, in turn vibrating the diaphragm which then creates sound waves.
Planar magnetic drivers operate on that same principle, but rather than using a coil to press against the diaphragm, they use a flat array of conductors that have been applied to a very thin film. In other words, the ‘coils’ sit directly on the diaphragm that’s positioned between two magnets. When an electronic signal is applied to the conductor array it becomes electromagnetic, leading to that aforementioned push/pull interaction between the conductor array and the magnets on both sides.
Planar Magnetic Drivers – Pros and Cons
One of the inherent drawbacks of traditional dynamic drivers is that there are a lot of mechanical parts that come into contact with each other, which can cause distortion at higher volumes (since higher volume = larger vibrations). Due to the fact that there’s less potential contact between individual components in a planar magnetic driver, it is much less likely to distort.
Due to the very thin and responsive diaphragm, a planar magnetic driver is also very responsive because it can quickly react to changes in the audio signal, which is a bonus if you’re listening to music with lots of changes and layers.
Overall, planar magnetic drivers provide incredible sound quality, but they come at a cost, both literally and figuratively. They are more expensive to produce, and due to the large magnets inside the drivers they’re also heavier and bulkier than some other drivers. They also require quite a bit of power to function properly, meaning that you will often need an amplifier to properly drive planar magnetic drivers.
Conclusion – Planar Magnetic Drivers
Planar magnetic drivers are drivers that you’ll traditionally start to see in higher tier audio products due to their cost and due to the fact that they often require amplifiers to drive them, making them less suited as a ‘grab and go’ type of driver. Planar magnetic drivers are known for their fantastic sound quality though, and critical listeners who are looking for a high fidelity listening experience will happily trade away some of that portability and ease of use for the sound quality that these drivers can provide.
