How Do Wah Wah Pedals Change Your Guitar Sound?

In this video we look at how a wah wah pedal changes your guitar tone using a spectrum analyser. Wah Wah pedals act much like a band pass filter that can be shifted up and down the frequency spectrum. With a spectrum analyser we can see this effect visually.
Any questions or comments welcome.
All the best
Paul.

[drumkommandr]

Holy damn dude you're the only one on YouTube who can actually answer the question

[csselement]

Came here thinking it is likely a sweepable band pass filter and now it’s confirmed 👍

[patrickmurphy]

Just what I was looking to understand better about what a wah pedal does. THANK YOU

[BenjaminGriffin-dl]

Thank you for keeping it simple and straightforward Paul. Great video!

[aakaravaev]

That is amazing! Thank you, man! Finally explained.

[JulianA-trpt]

Something with some time averaging and other adjustments is great for analyzing filters like this. I use Voxengo Span VST in Reaper DAW.

I send white noise out from my DAW/interface line out, to a pedal, then back into the interface, with monitoring enabled but master send disabled (otherwise you'll create a feedback loop). This allows live data to appear on the return track VST.
I've used it to adjust wah's for maximum sweep, as they usually have a big dead spot on the top or bottom. You can absolutely pinpoint the filter's frequency peak this way.

I'll add, even on a stock 70s unit with big rubber bumpers, removing the bumpers is not needed, and adjusting the gear/rack and tweaking the potentiometer position is usually enough to achieve 100% sweep. I imagine those who adjust it backwards for "more bass" are mostly just limiting the harsh toe-down treble, while creating a huge heel-down dead zone. The potentiometers vary, though.

[mrpres]

Very scientific and excellent video! Thanks for sharing this

[jarredhager]

I love your videos man, they are always EXACTLY what I'm looking for

[ricardocontreras]

A comment after 3 years?...sorry for that. (and for my english). Thanks for your video. You don't know how useful for teachers and students your work it is. It's almost impossible to find a technical explanation about wah effect. Thanks again and keep on ...please

[hman]

So it changes the EQ so to speak. Thanks dude, excellent video

[guillermocorreatedesco]

Hello Paul, Which software you use to analyse the spectrum? RegardS!

[sauravghosh]

I liked the damn video. Thanks for the info. Very helpful.

[captainjackrana]

i always wondered what does the wah do internally.. thank you for this explanation

[edsonmarquezani]

I would like to know what is the Q parameter, then. The width of the band, I guess?

[TeleCaster]

I have 3 Wah's, they all affect the tone very differently.

[nickf]

Yes it was interesting. Love the wah pedal. One thing I don't like is how it changes the basic sound of the guitar signal when using the drive channel. I want to preserve the distortion sound as much as possible, just make it go wah. Otherwise, it is too harsh, treble on toe down and mud on heel down. I know thats how they work, but how do I preserve my original signal sound as much as possible??

[DavidRoyal]

Great Video! One Question: did you use your Computer as an Oscilloscope?

[mjrp]

In short: it’s a band-pass amplifier. Isn’t it?