Envelope follower / ducker

Following on from this topic https://forum.audacityteam.org/t/noise-gate-with-a-sidechain/45569/9 a question was asked about creating an effect that does the opposite of an envelope follower.

Here’s the plug-in, which I have named “Dynamic Mirror” (it is used to mirror the dynamic of one track onto another track.
As yet there is no documentation, but from looking at Trebor’s animation in the other post, I think it should be fairly easy to work out what it does and how to use it. If anyone would like to have a go at writing some documentation for this effect, that would be very welcome. Such documentation can be posted as a reply, and would ideally follow the general format used for plug-ins on this wiki page: http://wiki.audacityteam.org/wiki/Nyquist_Effect_Plug-ins

Original version (obsolete):
dynamic-mirror.ny (2.8 KB)
Click Here to Download the Latest Version

Thanks Steve.
In ducking-mode that’s a lot easier to use than AutoDuck, IMO …
dynamic-mirror demo (ducking).gif

Glad you like it.
Feel free to write some documentation if you have time :wink:
Do the “range” controls make sense?

If I imagine the sliders running vertically : rotated anticlockwise by 90 degrees …
dynamic-mirror demo (following)_.gif

It’s a shame that we don’t yet have vertical sliders for Nyquist plug-ins. They would be very appropriate here.

If applied to a duplicate of the control track, dynamic-mirror can be used to compress & expand the dynamic range …
dynamic-mirror used to compress & expand.gif
It’s the Swiss-army-knife of plugins : follower, ducker, compressor & expander.

Interesting - gives me an idea for a new feature.
Currently, if only one track is selected, it throws an error. Rather than that, perhaps a more useful behaviour would be for it to apply the selected track’s envelope to itself.

Add de-essing to the repertoire …
de-essing with dynamic-mirror.gif
The excessively sibilant frequencies, (6.5kHz -12kHz in this case), are used to duck.

Updated plug-in.

In this version, if only one track is selected, the plug-in follows the amplitude of the selected track, and then applies that envelope to the same track.
If multiple tracks are selected, the plug-in follows the amplitude of the selected track, and then applies that envelope to all other selected tracks (but not the first track).
dynamic-mirror.ny (2.82 KB)

NB: If repeat effect, (“Ctrl”+“R”), is used to repeatedly apply version-2 of dynamic-mirror to one track only, the effect being applied will be different with each repetition, because the control-track is changing, (not necessarily a bad thing, but perhaps counter-intuitive).

If there is a control track and a duplicate track, and dynamic-mirror applied repeatedly, the effect will be exactly the same every time. Plus, with the original track present, there is the opportunity to mix to dilute the effect on the processed track.

I can see how that might look a bit strange, but it does what it says and “repeats the effect” (the “effect” is to follow the amplitude envelope and then apply that as a gain curve).
If you don’t want that, then (as you’re aware trebor), you can use a duplicate track as the “control track”.
Also, we don’t really want to be retaining the envelope in RAM after the plug-in has finished as it could be quite large.

That’s a good trick :slight_smile:

Reverb reduction …
reverb-reduction with dynamic-mirror.gif

Dynamics Processing

Dynamic Mirror
(dynamic-mirror.ny) download

Author: Steve Dalton

Is an envelope-follower : it applies the loudness-envelope of one track to the selected track(s) below it.
It can also apply the inverted version of the envelope of the control track to other track(s) below when in ducking mode, (so is a possible alternative to AutoDuck).

When only one track is selected Dynamic-Mirror will re-apply its envelope to itself, (or its inverse when in ducking mode). Applying in “mirror” mode, (i.e. envelope-follower mode), to self, causes dynamic-range-expansion. Applying to self in ducking-mode causes dynamic-range-compression.

If used on stereo-tracks, Dynamic mirror uses an average of the two track’s envelopes.
So for some applications* you will need to apply it to separately to each stereo track,
(* e.g. if you want a flat envelope ).

however, applying different envelopes to a stereo track can cause a strange panning effect.

I tried to use the plugin and tried to copy/paste an “envelope scheme” from a project to another but I did not understand how it works… can you help me please?
Thanks :slight_smile:

With this plug-in you need to select two tracks (one above the other).
The dynamic shape (envelope) of the first track is applied to the lower track.

See the animation near the beginning of this thread for an example.

Uhmm I tried the options in the first animations at the beginning of the thread but I didn’t obtain the desired result.
I attach an image as example, hoping that I could be more clear in my request. Sorry I am not so expert with the program
Thanks for your help!

To make it work:

  1. Click on the upper track so that the track is selected.
  2. “Tracks menu > Mix > Mix and Render”

Then try the effect again.

Just wanted to chime in and say super cool effect!
I was searching for that exactly “inverted mirror” to gate one track from another,my intention was to mix variations of the same sound together…works perfectly. Lots of other possibilities as well.I am suprised no such plugin exist in Vst,even an envelope follower is very rare…i guess people think compressors,expanders,gate are the same but you don’t get the precision we have here.