What is the Function of an Envelope Follower?
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- KVRAF
- 1927 posts since 30 Oct, 2003 from Frolicking in Dirac's Ocean
I realized I could have posted this in the getting started...but could some kind soul help me to understand the uses/purpose for an envelope follower...I've seen it on a few synths and play with them randomly but I'm not quite sure what its function/definition actually is. Tried googling but gave up cause I couldn't get to the root of what I was looking for. Anyhow...thanks!!
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- Pick Me Pick me!
- 10242 posts since 12 Mar, 2002 from a state of confusion
from wikipedia:
"Envelope follower is the name for a device used in musical electronic environments that detects the amplitude variation during time of an incoming sound and produces a control signal that resembles it. Usually it offers the possibility to modify the attack and the release stages of the input signal.
It can be useful to drive an amplification stage to modify the amplitude time variation (Envelope) of the incoming sound or to relate other sounds amplitude to it, but can be also used to modify certain parameters of other controllable devices (Filters, Wave shapers etc.) in relation with the incoming signal's amplitude."
http://en.wikipedia.org/wiki/Envelope_follower
"Envelope follower is the name for a device used in musical electronic environments that detects the amplitude variation during time of an incoming sound and produces a control signal that resembles it. Usually it offers the possibility to modify the attack and the release stages of the input signal.
It can be useful to drive an amplification stage to modify the amplitude time variation (Envelope) of the incoming sound or to relate other sounds amplitude to it, but can be also used to modify certain parameters of other controllable devices (Filters, Wave shapers etc.) in relation with the incoming signal's amplitude."
http://en.wikipedia.org/wiki/Envelope_follower
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- KVRAF
- 12235 posts since 18 Aug, 2003
An env follower follows the amplitude shape of the incoming signal and sends out a control value based on that shape. Often they'll have gates on them, so that the control signal only turns on above a certain value. They might also have an envelope that controls the rate at which the follower reaches the level it's following, which can make the output less jumpy.
It's sometimes worthwhile sticking a low-pass filter in front of an env follower, with a real low cut-off frequency (like 70 Hz). That way you smooth out the input signal by removing faster frequencies, but retain the basic amplitude.
It's sometimes worthwhile sticking a low-pass filter in front of an env follower, with a real low cut-off frequency (like 70 Hz). That way you smooth out the input signal by removing faster frequencies, but retain the basic amplitude.
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- KVRAF
- Topic Starter
- 1927 posts since 30 Oct, 2003 from Frolicking in Dirac's Ocean
Thanks VitaminD and shamann...I'm still not sure how it differs from a typical envelope or when it would be used but that's through no fault of yours...just my lack of depth of synth knowledge...I am going to meditate on your answers until I get it!!
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- KVRAF
- 12235 posts since 18 Aug, 2003
A regular envelope doesn't follow the amplitude of the incoming signal. On a filter like the Kjaerhus Classic Auto-Filter, the incoming signal triggers a modulation envelope which rises and falls according the attack and release controls you have already set.
In contrast, an envelope follower would have no set attack or release, its shape would only be set by the peak volume of the incoming signal.
In contrast, an envelope follower would have no set attack or release, its shape would only be set by the peak volume of the incoming signal.
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- KVRAF
- Topic Starter
- 1927 posts since 30 Oct, 2003 from Frolicking in Dirac's Ocean