Superconducting voice coil - a route to increase efficiency of an electrodynamic loudspeaker

Loudspeaker is the most critical part of an electroacoustical chain, and construction and design are going in the direction of lowering distortion and increasing efficiency. Efficiency of a common loudspeaker is very low, below 1%. One way to increase efficiency of an electrodynamic loudspeaker is to use superconductors as the material for the voice coil. Standard characteristics of the electrodynamic loudspeaker, like vibration amplitude, output power and efficiency have been analyzed, when copper wire in the voice coil is considered to be replaced by superconducting single turn ribbon. It is evident an apparent increase of the efficiency in a broad frequency range. Basic conclusions have been experimentally tested on the copper voice coil with reduced electric resistance after cooling down to 130 K.