Wah-wah pedal
A wah-wah pedal, or simply wah pedal, is a type of effects pedal designed for electric guitar that alters the timbre of the input signal to create a distinctive sound, mimicking the human voice saying the onomatopoeic name "wah-wah". The pedal sweeps a band-pass filter up and down in frequency to create a spectral glide. The wah-wah effect originated in the 1920s, with trumpet or trombone players finding they could produce an expressive crying tone by moving a mute in, and out of the instrument's bell. This was later simulated with electronic circuitry for the electric guitar when the wah-wah pedal was invented. It is controlled by movement of the player's foot on a rocking pedal connected to a potentiometer. Wah-wah effects may be used without moving the treadle as a fixed filter to alter an instrument’s timbre (known as a “cocked-wah”[1]), or to create a "wacka-wacka" funk-styled rhythm for rhythm guitar playing.[2]
An auto-wah pedal uses an envelope follower to control the filter instead of a potentiometer.
Uses[edit]
The main use of the wah-wah pedal is by rocking the pedal up and down. By doing this motion, the pedal reacts by sweeping through the peak response of a frequency filter up and down in frequency to create a spectral glide.
A different function of the pedal is to use it in a fixed position, which changes how an instrument sounds by selecting a certain frequency range. A guitarist using the wah in this way selects a position on the pedal and leaves the pedal there. Depending on the position of the pedal, this will boost or cut a specific frequency. This can be used for emphasizing the "sweet spot" in the tonal spectrum of a particular instrument. One electric guitar player to use the pedal in this way was Jimi Hendrix, who revolutionized its application by combining a Fender Stratocaster with stacked Marshall Amplifiers (in both static and modulated mode) for lead and rhythm guitar applications unheard of before then.
Another famous style of wah-wah playing is utilizing it for a percussive "wacka-wacka" effect during rhythm guitar parts. This is done by muting strings, holding down a chord and moving the pedal at the same time. This was first heard on the song "Little Miss Lover" (1967) on "Axis: Bold as Love," by the Jimi Hendrix Experience.
The "wah-wah" and "wacka-wacka" effects are often associated with the bands on 1970s TV variety shows, like those of Sonny and Cher, Flip Wilson, or Donny and Marie Osmond; or with the soundtracks of pornographic films, the sound referenced in TV commercials for Axe body spray as "bow chicka wow wow."