A plasma speaker has no cone, no voice coil and no suspension. The diaphragm is the arc itself. Every conventional driver moves air with mass. A cone bonded to a coil accelerates inside a magnetic gap and drags the surrounding air with it. That assembly has inertia, and inertia smears transients and caps high-frequency response. A plasma speaker deletes the moving mass entirely. The mechanism is thermoacoustic rather than mechanical: - A high-voltage supply, typically a flyback transformer switched by an IGBT under a 555 astable or TL494 PWM stage, sustains an arc across a small electrode gap. Dry air breaks down near 3 kV per millimetre, after which the ionised channel turns conductive and the voltage across it collapses. - The channel runs at several thousand kelvin. Audio is impressed on the carrier by modulating pulse width or switching frequency, which modulates the power dumped into that channel. - Rapid heating and cooling expands and contracts the air around the arc, radiati...