Parabolic loudspeaker

[1] The parabolic loudspeaker has been used for such diverse purposes as directing sound at faraway targets in performing arts centers and stadia, for industrial testing, for intimate listening at museum exhibits, and as a sonic weapon.

Limitations of parabolic reflector loudspeakers include the fact that they are comparatively large and bulky, and that they have a fixed beam width with no ability to broaden or narrow the coverage pattern without changing the curvature of the dish.

In some loudspeaker designs, a hole is cut at the center of the parabolic dish, or damping material placed, such that no sound is reflected directly at the speaker driver.

[1] The first use of a parabolic reflector in directing sound energy as a weapon was the Luftkanone designed by the German military during World War II.

The system for creating a shock wave of sonic energy relied on the combustion of methane and oxygen, with a frequency range of 800–1500 pulses per second.

Modern sonic weapons such the Long Range Acoustic Device (LRAD) rely on multiple loudspeaker drivers for increased sound power, and may array them in a flat plane rather than on a parabolic surface.

[2][9] In 2002, Meyer Sound produced the SB-2, a bi-amplified loudspeaker which uses a parabolic dish as the front face of the enclosure.

The narrow directionality of the parabolic loudspeaker and microphone aid in reducing the amount of stray sound that could skew test results.

[12][13] Each unit of the Holophones system consists of a parabolic dish with a limited band loudspeaker at its focal point, with controllable radiation angle.