This time, I will explain the envelope that I mentioned last time.
What is an envelope in the first place?
but this has nothing to do with the envelope I’m talking about. When I checked the etymology, there was nothing to make me say, "Oh, I see!"
Just remember, "an envelope is an envelope".
Specifically, think of it as "the volume from the start of the sound until the sound disappears."
↓ Such as this
There are various ways of interpreting envelopes, which can be said to be the character of a synth. However, there must be a "standard" to some extent, and among the many standards, the most common is "ADSR".
It's a difficult name, but it's just an acronym.
Attack ：Attack. The sound begins.
Decay ：Decay. After the peak, the sound drops until it stabilizes.
Sustain ：Sustain. The length or duration of the stable sound.
Release ：When the sound decreases to a stop.
To put ADSR more correctly,
Attack Time：Time to get up. Attack time.
Decay Time：The time it takes to decay and settle. Decay time.
Sustain Level：The volume at which the sound keeps going. Sustain level.
Release Time：Time until the sound stops. Release time.
(Everyone should have complained that Sustain is the only one called a "level"!)
To be honest, ADSR is not something you can see in the diagram. However, if you fiddle with the envelope as you did last time while looking at this diagram, you may feel like, "Oh, I see."
This sensation is the moment from when you play with the synth, and it feels “fun!” And this is the origin of the word “synthesis”. "Synthesis" is the search for a good sound while tasting it, and thinking "I'd rather add a little more salt ..." or "Let's add some sugar as a secret ingredient."
I would like to explain more, but this time was a new bit of information. If I explained it at once, you’d get full. So I decided I’ll explain the uses of the envelope next time.
Finally, I’ve made pictures of the envelope following the 5 classifications I mentioned in 2nd period. Please listen to each sound while looking at the pictures to get a solid image of each. If you can understand these, you will have grasped half of synth sound creation. (If I drew the figures exactly according to the actual parameter values, it would be hard to imagine, so I’ve slightly simplified them.)
Now, let’s enjoy controlling Envelopes with these feelings! Bye.