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Beyond a certain price, headphones divide into two camps that work on genuinely different principles. Dynamic drivers use a voice coil attached to a cone or dome, exactly like a miniature loudspeaker. Planar magnetic drivers use a thin flat diaphragm with a conductive trace on it, suspended between arrays of magnets. The difference is not marketing; it changes bass behaviour, distortion, weight and, importantly, what you need to drive them. This guide sets out how each works and which trade-offs come with it.

How a Dynamic Driver Works

A dynamic headphone driver is a small moving-coil transducer. A cylindrical voice coil sits in a magnetic gap, attached to a lightweight dome or cone diaphragm. Current through the coil produces a force, the coil moves, and the diaphragm moves with it. The technology is over a century old, thoroughly understood and cheap to manufacture well.

Its defining characteristic is that force is applied at one place — where the coil joins the diaphragm — and must propagate outwards across the diaphragm's surface. At low frequencies the diaphragm moves as a piston and this is fine. Higher up, the diaphragm can flex rather than move as a unit, a behaviour called break-up, and controlling it is much of the art of dynamic driver design.

Dynamic drivers are typically efficient, which is why they work from a phone, and light, which is why the headphones can be comfortable for hours. Their bass extends well but tends to roll off gradually at the lowest frequencies, and distortion generally rises as excursion increases at high levels.

How a Planar Magnetic Driver Works

A planar magnetic driver replaces the coil-and-cone arrangement with a large, extremely thin membrane — often a few microns of polymer film — carrying a conductive trace distributed across its whole surface. Magnet arrays sit on one or both sides. Because the conductor covers the diaphragm, the driving force is applied evenly across the entire surface rather than at a single point.

That distributed drive is the technology's central advantage. There is no coil-to-diaphragm interface to propagate force through, and much less tendency to break up, so the diaphragm moves more nearly as a whole. The consequences show up as very low distortion, particularly at high output, and bass that extends flat rather than rolling off — planar bass often measures ruler-flat down to 20 Hz and below.

The costs are physical. The magnet arrays are heavy, so planar headphones typically weigh 350–600 g against 250–350 g for comparable dynamics, and clamping force and pad design have to work harder for comfort. They are also usually less sensitive, and their impedance behaves differently, which brings us to drive requirements.

The Load They Present

Low Impedance, Low Sensitivity, Flat Curve

A planar driver's impedance is essentially resistive and flat across the audio band — commonly 30–60 Ω with almost no variation — because it has no resonant voice-coil-and-suspension system in the electrical sense. That is excellent for frequency response, since the amplifier's output impedance cannot reshape it. But combined with sensitivity often in the 90–100 dB/mW range, it means planars demand real current: low impedance and low sensitivity together are the hardest combination to drive. A dynamic headphone's impedance, by contrast, peaks sharply at its resonance, which is exactly where a high-output-impedance amplifier will add unwanted bass emphasis.

What Each Does Well

Reduced to their strengths, the two technologies are complementary rather than ranked.

Planar magnetic excels at bass extension and control, at low distortion when playing loud, and at a certain evenness through the midrange that comes from a diaphragm behaving coherently. The bass in particular is distinctive: flat to the bottom, tight, and unusually free of the bloom that a resonant system can add.

Dynamic excels at efficiency, weight and cost. A good dynamic headphone can be driven from anything, worn all day, and bought at a fraction of a planar's price for equivalent perceived quality. Dynamics also tend to have a more forgiving relationship with amplifier quality — though not with amplifier output impedance, as noted above.

What neither technology guarantees is tuning. The frequency response a manufacturer chooses matters far more to how a headphone sounds than which driver is inside it, and there are bright planars, warm planars, bright dynamics and warm dynamics. Driver type predicts a set of behaviours; it does not predict a voicing.

Electrostatic: The Third Option

A third technology sits alongside these two. Electrostatic headphones use an extremely thin diaphragm carrying a fixed electrical charge, suspended between two perforated plates called stators. Audio applied to the stators as a very high voltage creates a field that pulls and pushes the diaphragm.

Because the diaphragm is even lighter than a planar's and driven across its whole area, electrostatics achieve the lowest distortion and finest resolution of the three. The catch is that they cannot be driven by a normal amplifier at all: they require a dedicated energiser supplying hundreds of volts and the bias charge, which effectively locks you into a system purchase. They are also usually less capable in the deep bass than the best planars, since the diaphragm cannot move far. Worth knowing about, rarely a first serious headphone.

Practical drive rule: a planar with 96 dB/mW sensitivity at 40 Ω needs on the order of tens of milliwatts for comfortable listening and hundreds for headroom on dynamic material — more than most phones and many DAC dongles can supply cleanly. Check the amplifier's rated output into the impedance you actually own, not its headline figure, and prefer an output impedance below about an eighth of the headphone's impedance.

Choosing Between Them

The decision usually comes down to how you listen and what you will drive them with.

Quick Reference: Driver Types Compared

PropertyDynamicPlanar MagneticElectrostatic
Drive mechanismVoice coil at one point on the diaphragmTrace distributed across the diaphragmCharged film between stators
Typical weight250–350 g350–600 gLight, but needs an energiser
Impedance behaviourPeaks at resonance; varies with frequencyFlat and resistive, often 30–60 ΩCapacitive; special amplification
SensitivityUsually high — phone-drivableOften low; needs currentRequires a dedicated energiser
Bass characterExtends well, gentle roll-offFlat and extended, very controlledLeast extended of the three
Distortion at high levelRises with excursionStays very lowLowest
Cost for the performanceBest valueHigherHighest, system purchase

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