Dynamics expander

Good morning.
I’m using Audacity 3.1.0 and W10 v19043.
Sorry for the question, I kindly ask where to find a plugin that expands the sound dynamics (reverse process of the compressor).

I found a [u]simialr thread[/u] with some suggestions.

Or, the Noise Gate is downward expansion and the Clip Fix effect seems to boost the peaks even if you don’t have clipping.

Note that you can’t “accurately” reverse the compression and limiting on commercial recordings - You don’t know the compression settings, the various tracks may have been compressed before mixing, multi-band compression may have been used, and with limiting it’s impossible to know the original peaks.

GoldWave ($60 USD after free trial) has a compressor/expander effect with presets such as “boost loud parts” and “reduce quiet parts”. If you do try GoldWave note that it’s “confused” about the definitions of compression & expansion… Start with the presets (which are correctly described) and ignore the compression/expansion checkbox, at least until you figure-out what it’s doing.

Thank you for the link.

There is a free plugin which expands bass & treble (Mac&PC)…
[ It’s called an exciter, but it’s an expander. Dials go up to 10 but IMO 0 to 1 is the useable range ].

The paid-for (~$60) “Gentleman’s” version of TDR Nova plugin has multi-band expansion
Everybody (Mac&PC) should grab the free version of TDR Nova, (no strings attached).

A simple one-line Nyquist command that can be used in the Nyquist Prompt effect (see: https://manual.audacityteam.org/man/nyquist_prompt.html)

(mult (rms *track*) *track*)

The overall gain is less that 1 (makes everything a bit quieter), so you will probably want to apply the “Amplify” or “Normalize” effect after.

I’m getting a silent failure on stereo tracks with that code. [It works on mono tracks though]

Dynamic-Mirror.ny on mirror (envelope-follower) will do something similar on mono & stereo tracks,
and offers some control with attack/decay times …

Are you using an old version of Audacity?
It works for me with stereo tracks on Audacity 3.0.2 or later - I’ve not tested earlier than that, but it may require modification for older versions:

;version 4
(defun expander (sig)
  (mult (rms sig) sig))

(multichan-expand #'expander *track*)

Sorry for my ignorance, I’m not so experienced, how to install the Dinamic Mirror pluging.

https ://manual.audacityteam.org/man/[u]nyquist_plug_in_installer[/u].html

After installing you then have to enable it in the plug-in manager before it appears in the effects menu