You’ve probably seen the knobs on your virtual synths labeled ‘A’, ‘D’, ‘S’, and ‘R’. But do you know how to use them to fully control your sound?
These are very powerful knobs – they control the envelope, and therefore can change your sound quite drastically. Let’s take a look into how it works and how you can use it.
The first thing to understand is what the “envelope” is. It’s basically the “shape” of the waveform. In synthesis, it is the artificial change in the waveform over time.
A = Attack
Attack is the amount of time it takes for the waveform to reach full velocity after it has been triggered.
D = Decay
Decay is the amount of time that it takes the signal to fall back to the set sustain level.
S = Sustain
This is the level of the signal after the initial attack while the sound is still being triggered.
R = Release
Release is the time it takes for the signal to fall to zero after the trigger is released.
Now that you know what these do – how can you use them?
Depending on the synthesizer, you can apply these controls to the amplifier or the filters. If you apply it to the amplifier, you are controlling the overall sound level/output of the synth. This is good for global envelope adjustments.
If you apply it to the filters, you’re adjusting the timbre changes over time. This is how you can create the “pointy” synth that cuts off after the initial hit, for example.
The best way to learn about these and how you can adjust them to get different sounds is to simply play with them. Work with one at a time and try to hear the differences when applying attack to the amplifier and the filter. Move down the row and start developing your synthesis skills!