When you’re playing around trying to figure out what speed to run an LFO, sometimes it’s fun to hear a slow pulse that gradually increases to a quick pulsing sound and then maybe grinds up into audio range.
Well, if you’ve ever done that with the speed knob and thought it sounded cool, you can imagine having another LFO Control the speed knob for you.
Imagine a hub cap spinning or a coin spinning in its edge. It’s rotation sound is periodic, but as it gets closer to stopping and it tips over, the rotation speed increases and the pulses get quicker and then more quick. You could simulate that manually, or use an envelope to increase the LFO speed. But if you wanted to hear that same cycle over and over if the rotation speed getting faster as time goes on, you’d use another LFO to control an LFO.