Effects Guide: What's What With Wah
A pedal board classic since its inception in the '60s, here's your guide to the wonderful world of wah.
By Ken Pearsall
Few effects in the guitarists’ arsenal are so instantly recognizable. Even your non-musician friends know what it is. When this new device was designed (quite accidentally, mind you) it was thought to mimic the sound of a trumpeter using a mute, so the original intention was to market it to trumpet and other brass players.
Thankfully, the decision was made to issue it for guitarists. And when the first production wah pedal came out in the 1960’s, guitarists put them to use immediately. “Whole Lotta Love" by Led Zeppelin, “White Room” by Cream, and of course “Voodoo Child (Slight Return)" by Jimi Hendrix just wouldn’t sound right without it. A lot of effects come and go through stages of popularity–chorus in the 80’s and heavy use of phasing in the 90’s seemed to define the era–but the wah has always been in constant use. Stevie Ray Vaughan, Steve Vai, and John Frusciante are just a few of the great players who have made the wah a part of their sound.
What is a Wah Pedal?
A wah is a variable equalization boost pedal. It was invented by trying to redesign a midrange boost feature on an amplifier. They wanted to change the on/off switch to a pot, which would have been cheaper to produce.
When they rotated the pot throughout it’s range, it made a very vocal-like “wah-wah” sound. This is paramount to the wah effect, as the classic sound is created by the change of tone from sweeping this pot, as opposed to just turning the effect on. This would be very hard for a player to adjust while playing however, so they housed it in an expression pedal for foot control.
A legend was born.
Wah pedals - "wah" and "wah-wah" are interchangeable - took the world by storm, even inspiring George Harrison to write the song “Wah Wah” about the wah pedal given to him by his friend Eric Clapton. (Clapton also once gifted him a '50s Strat.) You can hear them play this song together on the 1971 live album, The Concert for Bangladesh.
While all wah pedals are a little different, the basic effect stays the same. Engaging the pedal boosts a narrow range of frequencies (bandwidth) and allows you foot pedal control to sweep the frequency center of this boost to create the wah sound.
The main difference in the different sounds of wah pedals out there is the Q, or quality, of the boosted range. While some wah pedals boost these frequencies in a very sharp Q, which looks like a narrow peak and sounds more aggressive, other wah pedals have a wider bell curve Q, which lends itself to a smoother, more natural sound.
Quite a few wah pedals these days have a knob on the side to adjust this peak from sharp to narrow and all points in between.
Sweeping You Won't Complain About
The most common use of this effect is called "sweeping"; Playing while moving the pedal to create the “wah” sound.
This is the sound of Jimi Hendrix’s “Voodoo Child (Slight Return).” There are a couple ways to use this technique:
Sweeping Technique 1
You can sweep the pedal through it’s range in sync with the tempo of the song.
Sweeping Technique 2
You can sweep it after picking a note or chord to add emphasis and emotion to the sustain.
Usually you hear a combination of these techniques when used in popular songs. Jimmy Page’s guitar in the intro to Led Zeppelin’s “Dazed and Confused” is a great example of rhythmic wah. The fast rate of movement gives it an almost delay-like quality as the notes fade out.
Using a wah after picking to add emphasis or special FX has never been better exemplified than by Steve Vai on his song “Bad Horsie” from Alien Love Secrets. Amazing licks and wah control lend the horse sounds to the track, and the way he slowly sweeps up the pedal as he’s sustaining notes adds a taut drama to the track.
This sweeping effect can happen as slow or as fast as you can move the pedal. For an even quicker wah effect, you can use a stompbox known as an Auto Wah, or Touch Wah. This device reacts to the intensity of your picking (or, pick attack) to trigger the wah effect at a selected speed and can be used to wah up or down for every note even in extremely fast picking runs. Envelope Follower stompboxes are also very popular for effects like this, except that you normally also get to select filter type and other features. But the effect can be remarkably similar.
Can I Park Here?
Another popular use for wah is called “parking.”
This is when instead of sweeping the pedal, you engage the effect and pick one spot to leave the pedal at to emphasize a frequency range for your tone. Many players park their wah pedals and boost their signal for solos to really stand out from the band. Some leave it that way all the time.
Mick Ronson, David Bowie’s guitarist from the late-'60’s to the mid-'70’s, was very well known for this. Listen to “Ziggy Stardust” from the album Ziggy Stardust and the Spiders From Mars to hear this in action.
This use of the wah has become so popular and widely used that you can now buy regular stompbox pedals that do this exclusively. This is great for having the effect set up in advance and having an instant-on option instead of needing to engage it then find the sweet spot for your tone.
Where Does Wah Go in the Effects Chain?
Now that we know how to use a wah, we should discuss where in the signal chain it should be placed. The sound you get from your wah can change drastically depending on how you use it along with other pedals. Every guitarist has his or her own preference, and you will, too. There is no right or wrong, just different sounds that can be obtained.
One Option: First in Line
One method is to place it first thing in the signal chain. This allows you to use it in front of a distortion effect for instance, and use the boost of the wah to effect more distortion on the range you are boosting. This can be very interesting, and there are a ton of tone possibilities with this method.
Placing it as the first effect also keeps that classic wah sound, just as if you were using the pedal on it’s own. This does tend to add noise to the signal though, especially if you’re using a distortion pedal after it. While using it momentarily for sweeping it shouldn’t be an issue. This could be problematic if you are parking the wah though.
A Second Opinion: End of the Line
Placing the wah at the end of the chain tends to take a lot of the sharp peak off the boost. This is due to the wah no longer being driven by your guitar circuitry, and being fed from the output of other pedals. Most pedals have an output buffer which changes the impedance of your signal to prevent loss of treble on long cable runs (or effects chains) but this does affect the way the wah sounds. Some guitarists think it can sound smoother, and some think it sounds wimpy. What is certain is it can take on a sound more like a normal treble filter cut, and loses some of that edginess. This can be very beneficial for the parked wah sound, or if you’re going for a Tom Morello/Rage Against The Machine vibe.
No matter what genre, wah has a home in it. Whether it’s Chet Atkins or Kirk Hammet, bluegrass or new wave, punk or pop (or pop-punk for that matter), wah has been a part of it all. It will be a part of genres not yet invented, and long after we’re all gone.
It’s an absolute classic that can lend your music an instant sense of familiarity or an aggressive edge that grabs the listener and makes them take notice.