ADSR effect

What is Envelop & ADSR

The envelop of a sound describes the way the amplitude varies over time. How it gets louder & softer overtime. The envelop is mostly divided into 4 sections – Attack, Decay, Sustain, Release. Combinedly named ADSR. Together, they make up the ADSR envelope. An ADSR envelope determines how a sound unfolds over time.

ADSR controls all sounds, it effects in any kind of sound creates in any sources, in any genre. It most commonly found on VST synths, hardware synths and samplers.

Attack

This is the time it takes to go from generating the sound until it reaches the full amplitude. It’s the initial run-up of level from nil to peak. There are two types of attack. Short Attack & Long Attack. Short Attack takes shorter time to reach the pick. Like Drum sounds, plenty of others in this genre. Long Attack needs longer attack-time. Example Sound creates by a bow.

Decay

This is the time it takes for the level to drop to the sustained level, when the attack time is over. A lower sustain and medium decay emphasizes the initial punch. Higher sustain and longer decay creates a sound overpowering and big. It is the time taken for the subsequent run down from attack to sustain level.

Sustain

The amplitude almost stabilizes in this level. In sustain,  during the main sequence of the sound’s duration, until the key is released. In this level, the sound maintains, when a note is on hold.

Release

It’s the time taken to go from sustain level to complete silence. The release is the ‘Tail’ of the sound. Depending on the sound that you are working with, & the location of the sound has been recorded at, the release contains some natural reverb of acoustics of the location. Long release time will you give you some nice long tails. Tails on sounds will give the relative track some added texture and space without applying effects right away.

The ADSR slope can be seen as

fade in – drop in level – sustain level – fade out.

Changing the envelop of a sound can drastically change the way we perceive it. ADSR opens a whole world of sound creation possibilities. A common feature on many synthesizers is an AD envelope (attack and decay only). This can be used to control the pitch of one oscillator. In shaping the dynamics AR ( attack & release only) used to be in practice.