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.
However, because the pump still has to produce head or pressure, the pump can only be slowed by 10%, which actually makes the pump use more energy than a properly sized pump without a VFD. Still others will make a big deal about how the motor amps are reduced as the RPM is reduced with a VFD.