Diagram of normal sinus rhythm as seen on ECG. In atrial fibrillation the P waves, which represent depolarization of the top of the heart, are absent.
The wah-wah pedal is based on a simple concept but its effect is far more dramatic. Using a powerful filter to sweep through a broad frequency spectrum, the wah pedal boosts and exaggerates specific tones. Creating sounds that range from thick, flubbery bass to scratchy, stinging treble.
Technique [edit]. The wah-wah effect is produced by periodically bringing in and out of play treble frequencies while a note is sustained. The word is derived from the sound of the effect itselfâin other words, it is onomatopoeic. The method of production varies from one type of instrument to another.