A wah effect guitar pedal applies a filter to the sound of the guitar, then smoothly raises and lowers the frequency of the filter as the guitarist plays. The wah effect features prominently on many recordings by guitarists like Jimi Hendrix and Eric Clapton. You can create your own virtual wah effect pedal using Ableton Live's built-in "Auto Filter" plugin, then apply it to digital audio that you've recorded or a MIDI instrument.
Launch Ableton Live. Open the project containing the audio track to which you want to add a wah effect. Click the track to select it.
Click the "Live Device Browser" icon. Open the "Audio Effects" section. Drag and drop the "Auto Filter" entry onto the track.
Click the "Bandpass" icon. Drag the yellow circle in the Auto Filter window to the left until the frequency readout displays "300 Hz."
Turn the "Amount" knob in the "LFO" section up to "30.0" and set the "Phase" knob to "0.00." Click the "Shape" drop-down menu and select the triangle icon. Turn the "Offset" knob to "180."
Click the music note icon next to the "Rate" knob, then click and drag the knob to change the speed of the wah effect. Start with a rate of "1/2," then try different rates until you get the desired wah sound. Tweak the other settings as desired to fine-tune the effect.
Some versions of Ableton Live include a built-in wah effect in the "Audio Effects Rack" section. For a manual wah effect, disable the LFO and sweep the filter manually as you record.