How to create an envelope follower in Reaktor 6 Primary and set your synth to automatically follow the amplitude of drums.
An envelope follower is a device that converts the amplitude envelope of an audio input into a control signal. Once we have that control signal, we can use it to control whatever we want. We can make the amplitude of an oscillator follow the amplitude of the input, or we could move the cutoff frequency of a filter, panning, etc.
Building the envelope follower is rather straightforward, just two steps: of rectifying and then low-pass filtering. In this video I walk through the process, and then show a few different applications.