Gear & technology
Planar magnetic
Also called planar, orthodynamic, isodynamic
A planar magnetic driver is a thin, flat diaphragm with a printed conductive trace, suspended between magnets. The whole diaphragm is driven at once, instead of from a single voice coil as in a dynamic driver.
In a dynamic driver, a coil attached to the middle of a cone pushes it back and forth. In a planar magnetic driver, the current runs through a pattern across the diaphragm itself, so force is spread over its surface. The aim is a more even, controlled movement and a faster Transient response.
Planar headphones tend to be larger and heavier than dynamic ones. Many have a low Impedance but low Sensitivity, so a phone may not drive them well even though the ohm figure looks easy. The HiFiMAN Sundara and Audeze LCD-2 are typical examples.
Makers often cite low distortion and tight bass; whether you hear a difference from a good dynamic design is a matter on which listeners disagree. Most planar headphones are Open-back, which is part of why they are associated with a wide Soundstage.