When purchasing an in-ear monitor, many consumers face a tough decision between balanced armature (BA) and dynamic drivers.
While the two types of drivers may sound similar (both send vibrations through your ear canal to produce sound), they each have their own unique traits.
Overall, the type of driver you choose largely comes down to personal preference and desired sound characteristics.
It is also important to keep in mind that not all BA and dynamic drivers are created equal — some can be better than others depending on specifications such as frequency response range, sensitivity, and impedance.
Dynamic earphones operate through a different process than most electronic devices — rather than using a fixed electrical circuit, they use a vibrating diaphragm and voice coil. The diaphragm is the part of the driver that actually moves to produce sound, while the voice coil causes it to vibrate by oscillating back and forth — this essentially produces an electric current that carries sound through the device.
Dynamic drivers are typically made from paper or plastic, and they come in one of two types:
either open-back or closed-back. Open-back earphones offer a wide, natural-sounding frequency response with minimal noise isolation; on the other hand, closed-back models can be used for monitoring purposes as their increased isolation helps block out ambient sounds on stage.
Dynamic drivers tend to offer a relatively balanced listening experience across all genres of music — hip hop, rock, folk, etc. T
hey are typically capable of producing a nice low end without significant coloration, and they also produce rich mids and highs that allow voices to sound clear and full.
Because dynamic drivers are less complex than their BA counterparts, you will generally find them at lower price points than universals with multiple balanced armature drivers.
Despite their name, dynamic models do not handle frequencies as high as some other types of earphones can produce.
This is due to both the vibrating mechanism itself (as it must be larger in order to push out the same amount of air) and because higher frequency pitches tend to tax any driver more heavily than lower ones.
Dynamic models also vary significantly terms of price/quality — cheaper ones use thin diaphragms and may not be capable of reproducing certain frequencies, while more expensive ones offer stronger bass and clear treble.
Balanced Armature Drivers
Balanced armature drivers work slightly differently than dynamic drivers — they actually sit perpendicular to the sound wave (instead of parallel like a dynamic driver), and pass through two transducers that face either side of the canal.
This basically creates a more efficient system that can reproduce both high and low frequencies with less power; on top of this, BA drivers are known for their accuracy in reproducing sound and providing excellent isolation from background noise.
However, because balanced armature designs require multiple pieces to function properly, they tend to be more complex than some other types of earphones.
Universals with multiple balanced armature drivers are capable of producing the widest range of frequencies, making them great for monitoring (with one driver handling treble and high-mid frequencies while another takes care of bass).
They also allow for more precision when it comes to frequency response — because each earphone can be tuned specifically to handle certain ranges, you typically get consistently smooth sound throughout the entire spectrum.
The level of noise isolation is also impressive since there are no ports that allow sound to escape around your ears; in fact, many models offer additional interchangeable tips that create even stronger noise cancellation by literally plugging up any empty spaces between the tip and canal opening.
Finally, balanced armature earphones tend to have a sleek, ergonomic design that rests comfortably in the ear without requiring any kind of loop or over-the-ear fit.
As their name implies, balanced armature drivers are more complex than other types of earphones.
The technology itself is still pretty new to this market (compared to dynamic drivers), which means you will be paying a bit more for universals with multiple BA drivers — they are generally priced at least $100 USD.
Even then, however, there are no guarantees when it comes to sound quality; many models will produce major frequency imbalances and sculpting issues across certain genres — some high frequencies may sound way too sharp and sibilant while others lack depth and clarity.
Another drawback is that balanced armature designs actually have a higher impedance than most other kinds of earphones.
In order to reproduce sound, they must be driven by more powerful amplifiers — this is why you will rarely find BA drivers paired with anything other than an iDevice or MP3 player.
Finally, balanced armature designs cannot produce the same amount of bass as models with multiple dynamic drivers.
This doesn’t matter much in genres like classical and jazz where it’s not really essential, but in genres that rely on a strong low-end response (hip hop, rock, etc.), universals with multi-BA drivers simply won’t be able to handle what your music asks from them.