Invented in the 1800s and still widely used today, conventional moving-coil drivers feature a coil of wire inside a magnet glued to a stiff cone. Current passes through the coil and electromagnetism creates force that vibrates the coil, along with the stiff cone to which it’s glued. Electrostatic drivers operate based on a completely different, more advanced principle. They work by placing a static (non-moving) electric charge on an ultralight film floating between two perforated metal plates. Static cling and repulsion cause the entire film to move by itself when audio voltages are applied across the plates. Because there is no physical contact or interference from coils or stiff cones—and because the film is so thin—electrostatic headphones produce a superior sound, characterized by a lack of coloration and distortion. But since they require a high-voltage power supply and are more expensive, they have historically been less accessible than their moving-coil counterparts.