The structure of the electrostatic loudspeaker is the same as that of a capacitor. Here, the loudspeaker diaphragm can lie between the two electrodes
and be controlled by the electric field; however, it can also be one of the electrodes. In electrostatic operation, two electrodes with equal charge repel each other, while two electrodes with unequal charge attract
each other.If a voltage
is applied to the electrodes of an electrostatic loudspeaker, the voltage level is a measure of the deflection of the electrodes. A high voltage causes a large deflection, a low voltage causes a small deflection, and a reversed-polarity voltage causes a deflection in a different direction. The force acting on the electrodes depends on the electrostatic field constant, the plate area and is proportional to the square of the voltage.