Resonator
From Wikipedia, the free encyclopedia
A resonator is a device or system that exhibits resonance or resonant behavior. Many objects that use resonant effects are referred to simply as resonators. Examples of resonators are discussed in this article.
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[edit] Electromagnetic
A distributed parameter resonator of the distributed network type has capacitance, inductance, and resistance which cannot be isolated into separate lumped capacitors, inductors, or resistors. The time factor of propagation of wave energy in the network is appreciable. Resonators can be of the dielectric type or magnetic type.
A hollow conductor that uses resonance to amplify an electromagnetic wave is called a cavity resonator.
[edit] Automobiles
A resonator is one part in exhaust systems that works with the muffler to reduce noise, by making sound waves "cancel each other out"[1]. The "exhaust note" is an important feature for many vehicle owners, so both the original manufacturers and the after-market suppliers use the resonator to enhance the sound in some way - in particular so-called "ricers" use resonators on their 4-cylinder engines to give an exhaust note comparable to that of a V8 engine.
[edit] Musical instruments
Most musical instruments include resonators to enhance the sound of the instrument. In many keyboard percussion instruments, below the centre of each note is a tube, which is an acoustic cavity resonator, referred to simply as the resonator. The length of the tube varies according to the pitch of the note, with higher notes having shorter resonators. The tube is open at the top end and closed at the bottom end, creating a column of air which resonates when the note is struck. This adds depth and volume to the note. In string instruments, the body of the instrument is a resonator.
In Camille Saint-Saëns' Danse Macabre, a skeleton's dance is depicted by a xylophone. Since the instrument in Saint-Saëns' day did not have resonators, it is often performed with resonators removed (or covered). This makes sound of the instrument more brittle and bone-like.
The vibrato effect of a vibraphone is obtained by a mechanism which opens and shuts the resonators.
String instruments such as the bluegrass banjo may also have resonators. Many five-string banjos have removable resonators, to allow the instrument to be used with resonator in bluegrass style, or without in folk music style.
The term resonator, used by itself, may also refer to the resonator guitar.
