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.
It's recorded with a wah wah in the low position used as a filter. That was the first time we did anything like that. It was Chris's idea; he wanted to get that weird tone that you can't really dial in on an amp. But if you use the wah wah as a filter, it gets an incredibly weird sound.