What is "Envelope"?

[samb]

On a pedal or I suppose anything, what does "Envelope" mean? I know the Moog MuRF pedal has an envelope knob. I just do not understand what it does. Can someone break it down for me?

[Texas Noise Factory]

If you look at old synths or envelope filters, you'll see on synths a knob that says ADSR which stands for attack, decay, sustain, and release. These knobs settings determine on a synth how long it takes for the sound to start, how long it sustains, how long the decay of the sound is and finally after you have finished hitting the note, how long it takes to go away. (release) On envelope filters you have a knob that says release or decay. this determines how long the effect will happen. short setting, quicker attack and release, and for a longer setting, a longer release. Hope that helps a bit. What pedal are you working with, or asking about in particular?

[samb]

I'm working with the MuRF Moogerfooger

[the_big_geez]

I'm going to take what TNF said one step closer to simplicity:

 

WHat he told you relates to how it is applied in technology, but the term actually derives from something more basic. It helps to understand the fundamental history.

 

Every sound has an envelope.

 

The envelope is what describes the sound from its beginning to its end. It's like a sound is all held together in time from it's start to it's end and can be all put in one place, and filed. Like it's in an envelope, in a folder, in a drawer, in a cabinet, etc... You can keep track of it, just like mail.

 

The basics of a sound envelope are Attack, Decay and Sustain. A perfect example of a soundwave as an envelope is a snare drum: It would look like this: /. The first ramp (/) is the attack; the second () is decay.

 

It's almost an on-off sound. It starts very abruptly, then reaches its peak and disappears almost as fast.

 

A different drum, like a floor tom might look more like this: /_. It comes on fast, dies fast, but holds for more time than the snare. The '_' indicates the sustain.

 

These are essential principles that must be known if you are using an analog synthesizer, for it you don''t know how the envelope of a saxophone differs from a snare drum, you will never even sound CLOSE to a saxophone!

 

(There's a bit more to it, but time and space don;t permit a full explanation)

 

Yeah, we've grown quite a way from analog synths that took up your whole dining room and had big knobs to control every facet of the sound, but the terminology and meaning still remains; no matter how you slice it, it's still physics! ANd if you twiddle the knobs the wrong way, they don't produce the intended effect! (This is true even among biological synthesizers! (wimmenz).

 

 

By understanding the above, you have scratched the surface of what those controls mean, and what to do with them.