We’re going to take a look into what ADSR is and how it works. ADSR stands for Attack, Sustain, decay and release. Each element of ADSR determines the shape of a sound for lack of a better word. Producers will tweak the ADSR of different elements of a sound to make a synth sound like it is in motion. Without ADSR, most sounds will feel flat and constant.
Attack determines how quickly a parameter comes to its maximum designated point of modulation from the starting point. A fast attack will cause the parameter to almost instantly reach its maximum, while a slow attack does the opposite. A slow attack on the gain or volume of a synth will produce a slowly rising sound that progressively gets louder and the attack reaches its maximum.
Decay is what sets the level prior to the sustain of a parameter. Often decay is unused, but it is still an important part of ADSR. If you want a parameter to max out to a certain point and then drop down to a lower level before the sustain, then you would have the decay decline to a lower level.
Sustain determines how long a sound remains at it’s parameter value after the decay ends. A short sustain will quickly segue into the release. A long sustain will cause a sound to ring out until the sustain ends. The length of the sustain you choose will vary based on the desired effect.
Release will determine how a parameter phases back to the base point. A fast release should be used if the desired effect is an immediate stop after the midi information for a note ends. A slow release will cause the parameter to slowly return to the original starting point.
Overall that’s the simplest way to understand ADSR. Try using the ADSR in your favorite synths to see what kind of sounds you can get!