Envelope-filter effects - or envelope effects - are closely related to wah-wah or phaser-like effects but taken to a more extreme level. The most important of these is the auto-wah.
The auto-wah, through the adjustment of the controls on the pedal, acts on the peak of the filter to accentuate some frequencies while the rest are lowered in volume or even muted. The greater the amplitude of the signal entering the pedal, the greater the ability of the guitarist to accentuate or not accentuate the effect based on the dynamics in which he plays.
Among the most interesting auto-ah pedals you will find the BOSS AW3 and the Electro-Harmonix QTron in the shop.
