Dynamic Decompression?

I've asked this in the past but never got a clear answer so here goes again...

Is there any software/filter/etc that would on-the-fly (preferred) or offline allow me to undo dynamic compression? Is this at all possible really? Obviously the distortion coming from this compression cannot be removed...

A dynamic range expansion filter is possible, but it won't restore the original since it's impossible to know the exact compression applied at each point in the track.

Here is a good example of a multi band compressor. If you watch the video you can get an idea of what happens and how difficult it would be to roll that back unless you have the original recording stems and software.

http://www.fabfilter.com/products/pro-mb-multiband-compressor-plug-in

In addition, there are many hardware compressors used that change sound in the analog domain, which would be impossible to roll back.

I found one, after doing some searching on this. I was wondering the same, some music is so compressed or clipped it's almost unlistenable, so why not try to decompress it a bit. And there is one that does an impressive job, 'perfect declipper'. It can declip and 'restore' some of the natural dynamics. There is a free plug in that has some peeps and advertisement every minute or so, but I was able to use it with Foobar. The results are quit interesting. I haven't tried it yet with the Red hot chili peppers' Californication or Jagged little pill from Alanis Morisette, to name some great but horribly mastered music. There are a lot of options to try, it's fun and worth the try.

I would LOVE to find such a device/program that worked!!!

I've asked this in the past but never got a clear answer so here goes again...

 

Is there any software/filter/etc that would on-the-fly (preferred) or offline allow me to undo dynamic compression? Is this at all possible really? Obviously the distortion coming from this compression cannot be removed...

There are plugins, for studio use, such as

Avid | Pro Expander

Most multi-track recording software bundles contain some kind of compressor/expander.

More commonly called and used as noise gates. Typical use case are for example drum microphone channels, to cut out background music and noise when drum is not being hit. Noise gate has some input threshold where it opens. Expander has more gentle curve. Expander has inverse input-vs-output gain slope compared to compressor.

Thx guys... Will try ...

Thx guys... Will try ...

Reaper would be a good choice. Its very powerful, but easy to use.

REAPER | Audio Production Without Limits

I've asked this in the past but never got a clear answer so here goes again...

 

Is there any software/filter/etc that would on-the-fly (preferred) or offline allow me to undo dynamic compression? Is this at all possible really? Obviously the distortion coming from this compression cannot be removed...

Stereotool has a couple of modules that try to ameliorate the effects of loudness-wars-mastering: Natural dynamics and Declipper (same as Perfect Declipper mentioned in previous post). It works live/on the fly as a VST plugin (Windows or OS X) or standalone application that you route audio to using JACK (OS X or GNU/Linux).

On 2/18/2016 at 8:52 AM, miguelito said:

Is there any software/filter/etc that would on-the-fly (preferred) or offline allow me to undo dynamic compression? Is this at all possible really? Obviously the distortion coming from this compression cannot be removed...

On 2/18/2016 at 2:00 PM, Jim Smith said:

I would LOVE to find such a device/program that worked!!!

(I realize this thread is presently bit old, but I think it's still right on topic, so I've chosen to revive it rather than just ignoring it.)

I've been using Fabfilter Pro-MB for some time now to reverse some of the effects of music track dynamic compression during mastering (but not mixing, of course).  I've found some interesting tidbits of information using it:

1) Dynamic expansion with a good multiband upwards expander (like Pro-MB) is possible if the dynamics of the music track haven't been completely crushed into oblivion. In DR Database terms, this means that if the music track has at least a 6-8 dB rating using the "TT Dynamic Range Meter" (the standalone version or as a plugin for foobar2000), you have a reasonable chance of a good listenable outcome using multiband expansion.  The maximum DR ratings that can benefit from expansion seem to be around 13-14 (dB-crest factor) on the DR Database scale.  Any tracks compressed to lower dynamic range values seem to be "lost causes".  It's much more productive to go on a hunt for a higher dynamic range version of the recording rather than trying to use a multiband expander.

2) The plugin settings used to expand tracks are usually most successful in increasing dynamic range in the higher frequencies of a track than the lower frequencies below ~100-200 Hz.  This means that the crest factor ratings of the tracks from the TT DR Meter may not change very much (due to the fact that crest factor is really measuring bass dynamic range, but not really higher frequency DR), but the tracks themselves will present a much more crisp and forward sound quality for dynamic transients--like ride cymbals, crash cymbals, bells/cowbells, glockenspiel, all handheld percussion instruments (particularly latin instruments), string attack transients, marimba/vibe strikes, drums, and human voice transients. 

3) The "steeliness" of string orchestras used in lush pop string arrangements and mass string orchestral scores (classical) will largely be suppressed if using the multiband expander carefully.  This was a big surprise.

4) Any human voices, particularly female voices, will begin to sound much more realistic and without typical harshness that comes with listening to recordings having compression applied during mastering.  This was the biggest surprise of all in my explorations using the expander.

5) The albums that respond most strongly and easily to multiband expansion seem to include those that had analog compressors applied during mastering (e.g., early-late 1970s albums), which apparently used continuously varying nonlinear compression curves without a sharp knee breakpoint/thresholding applied during mastering.

6) The music genres that seem to respond most strongly are funk, rock, folk, jazz (including smooth jazz), progressive rock with lots of drums/percussion, dance, and related genres.  Those genres that seem to respond with more difficulty include smoother music genres having lots of midrange energy (i.e., ambient, new age, classical string orchestras, etc.).

7) All tracks that have used multiband expansion need to be adjusted after expansion using parametric EQ demastering.

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It's clear to me that the use of a multiband dynamic range expander is now standard equipment for my typical demastering tasks that I perform on most of my incoming discs.

I don't recommend trying to do expansion "on the fly" (without review and adjustment of expander settings track by track) unless extremely mild expander settings are used, which leads to barely audible subjective differences in the compressed tracks.  Using an expander offline and taking a little time to get the setting right to get the best and most audible results is my strong suggestion in using these type of plugins.  However, the task only has to be done once for the music tracks--then saved for future listening, instead of having to set up a custom string of plugins and parametric EQ settings each time a music track is played.

Chris

On 7/26/2024 at 8:46 AM, Chris A said:

I've been using Fabfilter Pro-MB for some time now to reverse some of the effects of music track dynamic compression during mastering (but not mixing, of course). 

This is extremely interesting and I will give it a try at some point. Thank you for the info.