Horn speaker

Illustration of the sound wave propagation inside a horn speaker A schematic sketch of a speaker placed in front of a horn emitter His Master's Voice - a prototype horn speaker installed on Edison's phonograph Ultra-thin speaker as a work of art

Horn speaker - a speaker designed to improve the efficiency of its output by placing it at the inlet of the expanding tube.

Improving performance is achieved by adjusting the relatively high acoustic impedance of the diaphragm (rather rigid, generally made of paper, metal, plastic or similar materials) to low impedance open space. The tube acts as an acoustic transformer, where the impedance matching is better, the more the shape of the inner walls of the tube is similar to the exponential surface of the exponent - the figure determined by the rotating exponential curve. This condition is often not met, and usually the shape of the tube is simplified (eg to the shape of a cone or pyramid) or adapted to technological conditions, such as the shape of the speaker casing. Sometimes, to reduce external dimensions, the tube axis is not a straight line, only a broken line or a rolled curve (like a helicone or a tube).

The acoustics of the horn loudspeaker to the open space in terms of the lowest acoustic frequencies require very large structures, so horn loudspeakers are most often used where useful frequency response starts at frequencies of several hundred hertz (eg for human speech transmission in megaphones ), or in sets where other speakers are used to transmit the lowest frequencies; However, if the large size of the structure is not an obstacle (eg in cinema or stage sets), they are willing to be used for high efficiency.

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