A wah that follows your playing instead of a pedal or a clock. A resonant peak rises up the spectrum as you play harder and falls back as you play softer: the funk wah that tracks your dynamics.
An envelope follower listens to the level of the input, and that level moves a narrow, boosted band up from a resting frequency. Nothing runs on a timer, so the sweep only happens while you play, and its shape is the shape of your playing: a hard pick snaps it open, a soft one barely moves it.
The face groups the six controls into two strips.
Sweep
Shape + Blend
Auto Wah is a mono audio effect. It suits clean electric guitar best, but anything with clear dynamics works. Start from the Default preset, play a funky rhythm part, and adjust Sensitivity until your hardest notes open the filter all the way.
An envelope follower measures the input's level, and that measurement sets a resonant peak's centre frequency. Loud pushes the peak up toward Base Freq raised by Octaves, quiet lets it fall back to Base Freq. Nothing here runs on a clock, the sweep exists only while you are playing, and its shape is the shape of your dynamics.
The three remaining controls split cleanly between the detector and the filter. Sensitivity offsets the level at which the follower tops out, which is how you match the pedal to how hard you actually play; Q and Peak Gain shape the peak itself, deciding how narrow it is and how far it protrudes.
Web Audio has no envelope-follower node, so the browser preview builds one: a waveshaper rectifies the input, a one-pole lowpass at about 8 Hz averages it, and the result drives the filter's detune through a scaling gain. That is a genuine audio-rate follower, not an AnalyserNode polled from an animation frame, which would update only about once every 16 ms and smear exactly the transients a wah exists to track. Driving detune rather than frequency also makes the sweep exponential for free, so the same octave span sounds the same wherever Base Freq sits.
Describe what you want to make. Build it with the Studio agent.
A low-pass filter driven by an LFO.
A resonant low-pass filter for shaping tone.
A compressor with visible gain reduction.
