Whats interesting about wah-wah pedals
A simple effect turned into a distinctive and emotive foot pedal
Everyone knows the distinctive tone sweep a Wah-Wah pedal gives when you hear it featured in a song. It’s a great example of Onomatopoeia not by chance, but because the effect is made to mimic our own vocal abilities. I remember putting my mouth around my first cellphone’s speaker, opening and closing my mouth to distort the audio to get a wah-wah effect. It was amusing to influence the sound and emphasize certain notes on my ringtones. It turned every song into a reggae tune if I wanted. I later put together that depending on how much space my mouth had, it changed how much space the sound could resonate in. When my mouth was large the lower tones were more noticeable and a smaller space reduced the lows and increased the mids/highs.
This concept is what band-pass filters do and is essentially what a wah-wah is, with a similar frequency range as a human could produce. Band-pass filters have a band width and a frequency center. The frequencies within the band are passed through (and sometimes amplified) while the other frequencies are reduced (and sometimes muted). When you put your heel down on a wah-wah pedal you are moving the band to the lowest frequency, while the toe down position would put the band at the highest frequency. As a standalone effect with no easy way to control the main parameter this wouldn’t be nearly as interesting but could serve a purpose for developing a unique tone. What makes the wah a wah is how you sweep the band up and down the frequencies letting certain ranges through at the right moment and without too much effort.
The foot controller of a wah-wah is essential to its being and is such a simple modification that it makes me wonder why more pedals don’t utilize the same concept. If you pictured the wah pedal with a simplified design it would only have one knob that controls the frequency center, left is lower and right is higher frequencies. You would have a difficult time to control the band-pass filter in real time. So it was the engineers at Warwick electronics who had the task of allowing a saxophone player control the band pass effect while as they played. This was going to be an effect used by the musician in real time and not through post-production magic. What they did was modify an existing volume pedal to control the wah’s tone potentiometer (the part that sits underneath the knob) allowing for the player to use the effect while playing an instrument. The volume pedal design works by turning a potentiometer on its side and attaching a board to it allowing down/up movement to replace the left/right knob turns. Using gear ratios you can control the full range with minimal foot movement, making it second nature to the musician.
The pedal hasn’t changed much at all since the original design and the popularity blew up when Jimi Hendrix showed everyone what was possible with it. I can’t think of a reggae show I’ve been to that doesn’t have a wah-wah in heavy use. I imagine once you add it into your setup you won’t want to take it out because pumping the pedal adds live characteristics that most pedals can’t. I wouldn’t be surprised if carpel tunnel of the foot and ankle led to development of the auto-wah pedal.
Check out Hendrix making it all look so easy with his one handed playing and rocking the wah-wah: (jump to 0:55 to skip the banter, Medium/Embedly doesn’t support Youtube start times as far as I know)
