The driver is the part of a headphone that turns an electrical signal into moving air. Three designs dominate the market, and a fourth arrangement combines two of them in one shell. The driver type is printed on most listings, and it is one of the few spec fields that reliably predicts something practical: how much power the headphone needs, how heavy it is, and how it behaves at the frequency extremes.
Dynamic drivers: a coil, a magnet and a cone
A dynamic driver is a miniature loudspeaker. Current flows through a voice coil suspended in a magnetic gap, the coil moves, and a diaphragm attached to it pushes air. It is the oldest design in headphones and still the most common, because it is cheap to make, efficient, and good at moving enough air to produce bass.
Diaphragm area is the main lever. FiiO builds the FT3 around a 60 mm dynamic driver in an open-back cup at a stated 32 ohms and 110 dB sensitivity, while Moondrop specifies a 50 mm dynamic driver and 106 dB on the closed-back Joker. In-ear designs work with a fraction of that area, so the 11 mm dynamic driver specified for the Nothing Ear (a) has to rely on a sealed canal to generate low frequencies at all.
What changes for the listener: dynamic drivers are usually easy to drive from a phone, they produce bass without help, and their weakness is control. A large moving mass takes time to stop, which is the physical reason cheaper dynamic designs can smear low frequencies.
Planar magnetic drivers: the whole diaphragm is the coil
A planar magnetic driver replaces the cone and coil with a thin flat film that has a conductive trace printed across its surface, suspended between arrays of magnets. Force is applied evenly over the entire diaphragm instead of at one point, so the film stays flatter as it moves.
Two practical consequences follow, and both show up in the specifications. The first is weight, because magnet arrays are heavy. HIFIMAN lists the SUSVARA at 15.9 ounces, and Monolith builds the M1060 with wood cups around a planar driver. The second is sensitivity. The SUSVARA spec sheet states 83 dB, which is exceptionally low. A phone headphone jack cannot deliver enough voltage to drive that to a normal listening level, which is why planar flagships are sold alongside amplification.
Planar drivers have also arrived in ear-sized housings. SIVGA fits a 14.5 mm planar magnetic driver into the Nightingale in-ear monitor, quoted at 100 dB sensitivity, 20 Hz to 40 kHz, with a 4.4 mm balanced plug rather than a 3.5 mm one. The connector choice is itself a signal about the intended source.
Balanced armature drivers: tiny, precise, narrow
A balanced armature has no cone. A small metal arm sits balanced between two magnetic poles, and current through a coil tips it, driving a stiff diaphragm through a connecting rod. The moving mass is minuscule, so the design is fast and extremely efficient, and it can be made small enough to fit several units in one earpiece.
The trade is bandwidth. A single armature covers a narrower slice of the spectrum than a dynamic driver and moves very little air, so bass extension is limited unless the design compensates. Etymotic uses a single balanced armature in the ER3XR and publishes a range of 20 Hz to 16 kHz, which is narrower at the top than most dynamic in-ears claim and considerably more conservative than the marketing ranges printed elsewhere.
Hybrids: use each driver where it is strong
A hybrid puts a dynamic driver in charge of the bass and hands the midrange and treble to balanced armatures, with a crossover splitting the signal. Linsoul builds the KZ ZS10 Pro as four balanced armatures plus one dynamic driver behind a stainless steel faceplate with a detachable two-pin cable, and the five-armature-plus-one-dynamic CCA C12 follows the same recipe with one more armature per side. Hybrid arrangements have also reached true wireless sport models, where the listing will state a hybrid driver without saying how many units of each kind are inside.
More drivers is not automatically better. Every extra driver adds a crossover point, and a crossover is where the response can go wrong. Driver count is a manufacturing fact, not a quality claim.
Driver size is not a quality rating
Listings advertise diaphragm diameter because it is a number that sounds like more is better. It is not that simple. A larger diaphragm moves more air for a given excursion, which helps low frequency output, but it also has more mass and more surface area to control, which makes high frequency behavior harder. That is why a 60 mm dynamic driver and a 10 mm one are not competing at the same task, and why some in-ear designs hand the treble to a separate armature rather than asking one diaphragm to cover everything.
Enclosure matters at least as much. An open-back cup lets the rear wave escape, which reduces internal reflections but leaks sound in both directions, so it is unsuited to a shared office. A closed cup traps that energy and has to manage it, which is the design problem the closed-back Joker is built around and the reason its stated range stops at 22 kHz while the open-back FT3 claims 40 kHz. Neither figure is audible territory, but the difference tells you the two housings are solving different problems.
Weight is the other spec worth reading next to the driver type. A planar assembly is heavy by construction, and comfort over a long session is decided by clamp force and pad area rather than by driver technology.
What each type changes for you
| Driver type | Efficiency | Bass behavior | Usually needs an amp |
|---|---|---|---|
| Dynamic | High | Strong, less controlled | No |
| Planar magnetic | Often low | Extended and controlled | Frequently yes |
| Balanced armature | Very high | Limited without a vent | No |
| Hybrid | Varies by design | Depends on the crossover | Sometimes |
When the driver type means you need more than a phone
Sensitivity and impedance decide this, not the driver name by itself. If a headphone states low sensitivity, as the SUSVARA does at 83 dB, a phone output will run out of voltage before it runs out of volume, and the result is thin, quiet sound rather than distortion. That is the case for a dedicated source from the amplifiers category.
Scale the source to the load. FiiO publishes 2100 mW of output power for the desktop K9 Pro, which is aimed at demanding full-size headphones, while the pocket-sized KA15 dongle exists to give a laptop or phone a cleaner output than its own jack. If your headphones are efficient dynamic or armature designs, neither is necessary, and buying one will not make them louder in any useful way.
The short version: check sensitivity and impedance first, then read the driver type as an explanation for why those numbers look the way they do.
