A Wah Wah effect occurs by continually bringing in and out of play treble frequencies while a note is sustained. It is a modification of the vowel quality of a tone; that is, a type of spectral glide. Its name is an onomatopoeia: it mimics the sound it produces.
Wah Wah Effect: Its History
The first Wah Wah effect originated around 1920, when bass players discovered that they could produce an expressive crying tone just by moving a mute or a plunger in and out of the instruments bell. (Fun fact: after that, they began using the mute with the trombone as well.)
This effect developed accidentally. While engineers at Vox were working on a solid-state amplifier, a sudden circuit with odd audible effects came about. They began using it in an organ volume pedal chassis, as well as with brass instruments. Currently brass players frequently use these effects.
How It Works
Musicians produce the Wah Wah effect by foot-controlled signal processors that involve a bandpass filter with a variable frequency and a small bandwidth. The effect merges with the direct signal by moving the pedal back and forth and modifying the centre frequency.
Besides, an auto Wah Wah filter can let the low-frequency oscillator control the center frequency with parameters received from the input signal. A tremolo Wah Wah filter can produce a tremolo, which is the result of combining the effect with a low-frequency amplitude variation.
Wah Wah: Its Uses
To begin with, this effect is extremely expressive. Regardless, people associate it with diverse music genres. For instance, funk, soul, jazz, and rock have used this effect for decades. And, surprisingly, the peculiar sound of this effect has not changed over time.
Some Interesting Examples
Jimi Hendrix would use this effect by leaving the pedal in a specific location. As a result, his Wah Wah sound became a trademark of a funk and soul subgenre. Another case in point is Pink Floyd. This band employed the Wah Wah effect in the creation of the screaming sounds in their song “Echoes.” They produced this effect by moving the pedal back and forth as they connected the amp to the input and the guitar to the pedal’s output.