Gear & technology
Electrostatic
Also called electrostat, e-stat
An electrostatic driver moves an extremely thin, charged membrane between two perforated plates using high voltage rather than magnets. It needs a special energizer or amplifier, and is known for speed and delicacy in the treble.
The membrane weighs almost nothing, so it starts and stops faster than any dynamic or planar diaphragm. The cost is complexity: the driver needs a bias voltage of several hundred volts, so electrostatic headphones such as the Stax Lambda series plug into a dedicated energizer rather than a normal Amplifier.
Full-size electrostatic speakers, such as Quad and Martin Logan panels, apply the same idea at room scale, often with a conventional woofer for the Bass that a thin panel cannot move.
Some IEMs list electrostatic tweeters; these are small drivers driven through a transformer inside the earpiece, and products with them are usually described as Hybrid or tribrid.