In-ear monitors use one of two driver technologies — balanced armature and dynamic. In this article, we’ll discuss the technology behind these two designs and the pros and cons of each.
Balanced Armature Drivers
Balanced armature drivers are primarily used in hearing aids, but they also see extensive use in modern in-ear monitors. Most balanced armature drivers are tuned to sound good in a specific frequency range, and this is why many in-ear monitors contain multiple drivers. A crossover splits the sound signal into multiple frequency bands, and sends different frequency bands to each driver.
In a balanced armature design, an electric current is passed through a coil that is wrapped around an armature. The coil is suspended between two magnets, and the changes in current causes attraction between the coil and magnets.
Variations in the magnetic field moves the armature thousands of times per second. The in-ear monitor’s diaphragm is connected to the armature, and this movement produces sound that we can hear. A balanced armature is “balanced” because “there is no net force on the armature” when it is centered magnetic field.
Unlike dynamic driver designs, balanced armature drivers to not displace air in order to generate sound. There are upsides and downsides to this. Balanced armature in-ear monitors typically provide better isolation because there is no need for a vent to move air. On the contrary, balanced armature drivers lack the superior bass frequency presentation of dynamic driver designs.
- Drivers can be optimally tuned for specific frequency ranges.
- Smaller than dynamic drivers.
- Better treble performance than dynamic drivers.
- Faster response and more detailed sound.
- Bass response is not as good as dynamic drivers.
- Single driver designs are not as good as dynamic drivers.
- More expensive than dynamic driver designs.
Popular Balanced Armature IEMs
Dynamic driver technology is implemented into a variety of products including loudspeakers, headphones, and in-ear monitors. Unlike balanced armature designs, dynamic drivers are designed to cover the entire frequency range. While this often results in less detail from a scientific point of view, many people find dynamic drivers to be more natural sounding due to the absence of a crossover sending specific frequency bands to different drivers.
In a dynamic driver design, the diaphragm is attached directly to a voice coil. When a current is applied, the voice coil moves between two permanent magnets causing the diaphragm to move and produce sound. Dynamic drivers are sometimes called “moving coil drivers”.
Dynamic drivers are often vented and move air by design, and this results in a much better representation of bass frequencies compared to balanced armature designs. Because of their superior bass response, dynamic driver in-ear monitors are often used by bassists and drummers.
- Sound signature is more coherent
- Better bass response
- More durable and cheaper than balanced armature drivers
- Not as detailed as balanced armature drivers
- Larger than balanced armature drivers
- Not as popular as balanced armature designs
Popular Dynamic IEMs
Both balanced armature and dynamic driver designs have their pros and cons. It’s hard to definitely say which one is better because they both excel in different situations. In summary, balanced armature drivers typically offer a more detailed sound. Dynamic drivers offer a more coherent and powerful sound, and are often described as “warm-sounding”. Some companies also offer hybrid models that combine the defining qualities of both balanced armature and dynamic drivers.