Instead manufacturers refer to electrostatic amplifiers as energizers or drivers with STAX using the later terminology. Another term unique to electrostatic headphones is bias which references the ...

STAX SR-X1 Electrostatic Headphones (aka Earspeakers ... The new driver has a capacitance of 110pF and an impedance of 145k Ohms with a bias voltage of 580V DC. This results in a sensitivity rating of ...