How to Install Reverb in Audacity

Audacity is an open-source audio-editing program that I use on Ubuntu to lightly to edit some of my Shakuhachi recordings. It comes with a collection of filters which can be used for all kinds of effects – but on Ubuntu (and apparently all Linux distributions) it doesn’t come with a reverb filter which I like to occasionally use. Fortunately there is a reverb-filter which is also open-source and freely available – unfortunately installing it and using it causes too much unnecessary suffering.

Yesterday I had to go through this painful process again and fortunately I came across two simple solutions to both installation and using it – so I thought to make a note of it for myself for future reference.

Installation

LADSPA is some kind of standard protocol for audio filters (used by many other audio editing programs). The reverb effect is part of a large set of LADSPA filters which are installed as a set. Installing them should be as easy as downloading them and placing them in a certain folder – for the life of me I couldn’t figure out where that folder is. Most of the instructions I found seem to be for either outdated versions of either the filter set or Ubuntu.

I did however come across (here) an easy to use command-line installation which worked like magic (which I’m guessing means that the filters are somewhere in the official Ubuntu repositories). It installs an over-sized set of filters one of which is Gverb which is the one I was looking for:

sudo aptitude install vco-plugins tap-plugins swh-plugins rev-plugins omins mcp-plugins

Usage

The filter itself is a horrific set of of parameters which you have to be either a software engineer and/or a sound engineer to figure out.

I am neither – luckily I found these settings which worked great for me. If you have more refined audio-requirements then I do – you can probably use these setting as a good point of departure for exploring other variations:

• room size: 100
• reverb time: 3.5
• damping: .5
• input bandwidth: .75
• dry signal level: -1.5
• early reflection level: -22
• tail level: -22

I also came across this page (which I haven’t yet read) which seems to give some insight into what reverb is and how to about shaping it.

Previewing Tips

It really helps to be able to sample what the filter will do which is what preview does. Unfortunately the default configuration for preview is pretty useless – it’s too short ( just a few seconds) and starts at the beginning of the track. There are two things I did to benefit from a more useful preview.

First extend the duration of the preview to something like 20 or seconds. To do this simply go to “Edit -> Preferences -> Playback” and set the “Length of preview” to a longer duration:

Then before opening the filter select a portion of the sound-track you wish to preview:

WARNING: When you’ve found the reverb effect setting you like DO NOT click OK in the filter dialogue (see above) as that will apply the filter ONLY to the selected area (unless that is what you want). So far I have applied the effect to the entire track. To do this you need to close the filter dialogue (it will remember your settings), then select the entire track and re-open the filter window to actually apply it.

Sample Recording

You can listen to a sample recording I created with exactly these settings.