Electro-Harmonix Enigma Qballs Envelop Filter Bass Effects Pedal The Electro-Harmonix Enigma Qballs effects pedal is a powerful and precise envelope filter fine-tuned for bass frequency response. Sculpt your envelope to reveal a truly expressive tone, with a defined and unique signature. Enigma Qballs will deliver tight and smooth control over the complete 40 Hz to 3 kHz range, with a consistent and even sweetness. Envelope controlled filters are a unique type of sound modifier where the intensity of the effect is controlled by the user's playing dynamics. The volume and dynamic of the incoming audio signal is used to control a swept filter. As the volume increases or decreases so does the frequency of the filter. With 3 selectable filter modes, along with START, STOP, ATTACK, DECAY, Q and SENSITIVITY controls, Electro-Harmonix gives you many classic and modern Q sounds to play with to dial in vivid textures like never before. An analog distortion circuit was created specifically for the Enigma Qballs, and adds a dynamic edge to the filter's sound. Need some edge? Engage Enigma's analog distortion and dial in anything from subtle bite to dominating crush. You can even plug in an optional expression pedal to control the filter sweep with your foot. With the ability to adjust Q, sweep range, and filter type, Enigma Qballs bass pedal becomes one of the most versatile wahs available.