The driver is the most important component of any headphone, speaker, and IEM. They are the heart of your audio device since they are the ones responsible for sound reproduction. They are one of the key factors that determine whether a headphone/IEM will sound good or not.
Learning the concept behind these drivers is very important because they can determine what kind of sound an IEM or headphone produces. Of course, there are other factors such as shell acoustics and driver tuning that greatly affect the overall sound. However, knowing the most basic aspect of the building blocks of IEMs will greatly help you have a better grasp of their characteristics.
Also, if you’re new to the hobby, you might have heard confusing terms such as BA drivers, hybrid configurations, etc. That is because there are multiple types of drivers and with different kinds of capabilities and sound signatures.
In this article, we will be tackling the two most common drivers used in modern IEMs. We will be talking about balanced armature (BA) drivers and dynamic drivers (DD drivers). We’ll be going over their anatomy as well as their general sound characteristics. And also, we’ll find out if one driver type is superior to the other.
Balanced Armature Driver vs. Dynamic Driver
Balanced Armature Driver (BA)
The first type of IEM driver that we will be discussing is the balanced armature (BA) driver. You will commonly see this type of driver in most modern Universal IEMs and Custom IEMs (CIEMs). Balanced armature drivers were originally meant to be the successor to dynamic drivers due to their increased efficiency and more advanced technical capability.
The concept behind these drivers is that an electric coil is passed around a piece of metal called an armature. The coil around the armatures moves back and forth between the magnets, transmitting the movement to the drive rod and diaphragm.
The air is then moved in the chamber of the output nozzle and is released. The air does not move back and forth, allowing it to sound clearer compared to dynamic drivers.
Additionally, balanced armature drivers are small and lightweight, meaning you can fit more than one BA driver inside an IEM. This concept is called multi-driver IEM. Each balanced armature driver handles a specific frequency spectrum. And since the task of reproducing the entire frequency spectrum is handled by multiple drivers, the overall sound is significantly improved.
But with that said, balanced armature drivers aren’t perfect. They have their own sets of weaknesses. One of them is their bass response.
Compared to dynamic drivers, balanced armature drivers have a hard time keeping up. Yes, they can still sound thumpy and hard-hitting, just like dynamic drivers. However, the fullness and quality usually still can’t match dynamic drivers.
Another weakness of BA drivers is that they are prone to sibilance in the upper frequencies. This means that certain high-frequency sounds or the “S-Region” in vocals can sound harsh.
Of course, these can vary wildly since there are different manufacturers of balanced armature drivers. Some common manufacturers include Sonion and Knowles. These will also depend on the manufacturer’s tuning and implementation of the drivers.
Good performance in upper mids and highs.
Can use multiple balanced armature drivers in one IEM.
Small and lightweight
Bass response is considerably weaker than dynamic drivers.
Prone to sibilance
Another popular driver type that you often see in IEMs is the dynamic driver. Dynamic drivers are widely used in audio equipment because of their affordable price and wide availability. They are common in IEMs, headphones, earbuds, and loudspeakers.
Dynamic drivers used to be the only driver type used for IEMs. But with the advancements in technology, the balanced armature was developed as a smaller, lighter, and more capable alternative. Balanced armature drivers temporarily replaced dynamic drivers in the market.
However, manufacturers soon found out that they can use dynamic drivers alongside multi BA driver IEMs. They also found out that there are a lot of things that can be done with dynamic drivers to achieve a unique sound.
But before we dive into those, here’s the concept behind these drivers. The dynamic driver has a diaphragm that is directly connected to the magnetic coil, which moves when signals pass. This is why the Dynamic driver is also called the “moving coils.” The diaphragm vibrates when a varying current of an audio signal passes through it, this causes it to produce sound waves.
Compared to balanced armature drivers, dynamic drivers have better bass impact and sound more natural. This is because the diaphragm is connected to the coil.
When the coil moves back and forth, the diaphragm directly gets the same impact, like a rubber band snapping to a piece of paper. The movement of the coil and diaphragm displaces air around it, producing the bassy sound.
Since dynamic drivers produce better bass, they are used with IEMs that are specifically tuned to focus on the low end. They are also used in conjunction with balanced armature IEMs to help produce the better low end.
And as we mentioned earlier, manufacturers discovered different ways to modify the dynamic driver sound and help fix its shortcomings. Some of these modified drivers include graphene-coated and beryllium-coated dynamic drivers.
Of course, dynamic drivers have their own set of weaknesses. The most common downside to dynamic drivers is that they are generally inferior to the mids and highs compared to balanced armature drivers.
This is why a lot of single dynamic driver IEMs tend to have a V-Shaped tuning. Of course, this isn’t always the case and will highly depend on the manufacturer. After all, we have several high-end IEMs that solely use dynamic drivers, such as the Sony IER Z1R.
Creates good bass response
Not very good with upper frequencies.
Distortion sound in the music
In conclusion, neither of these driver types is superior to the other. Both dynamic drivers and balanced armature drivers are very capable options for IEMs. They both have their fair share of weaknesses, but they are overall very excellent performers.
When shopping for your next IEM, instead of basing your decisions solely on the driver type used, we highly urge you to try them out and see how the manufacturer implemented the drivers. After all, two identically driver models can sound completely different on two different IEMs.
Of course, knowing the general characteristics will tell if a headphone is capable of producing a specific frequency well. But at the end of the day, it is the overall sound signature that an IEM produces that you should be more concerned about.