I recently reinstalled my Linux Mint Cinnamon 17.2 operating system and Audacity 2.1.1. Audacity appears to be functioning just fine. But when I tried to reinstall the LF_rolloff_for_speech.xml plugin, Audacity has not recognized it. Here’s what I have done:
I unzipped the plugin and, opening the folder as root, I copied the file into:
/usr/share/audacity/plug-ins (which didn’t get recognized)
/usr/share/audacity/nyquist (which didn’t get recognized)
/usr/share/audacity (which didn’t get recognized)
I rebooted in each case. Presently I have copies of the file in all three locations. I have installed this plugin two or three times in the past, with no problem. However, I believe this is one version newer of Audacity, than before. I had 2.1.0 if I recall correctly. And, I am using Linux Mint Cinnamon 17.2 instead of 17.1. I don’t know if this might make a difference.
LF_rolloff_for_speech.xml is not a plug-in. It is a preset for the Equalization effect.
What you need to do is to import it into the Equalization effect.
Open the Equalization effect (You will need to have some audio selected to be able to open the Equalization effect).
Click the “Save / Manage Curves” button.
Click the “Import” button.
Navigate to where the LF_rolloff_for_speech.xml file is and select it, then click the “Open” button.
The curve has now been imported into the Equalization effect and will be available as a preset curve.
Click the “OK” button to confirm and close the curve manager window.
To use the effect, ensure that you are in the “Draw Curves” mode and select “LF rolloff for speech” in the “Select Curve” options.
Ideally this curve should be used with the “Length of Filter” slider set to maximum.
Unfortunately the handling of presets is a bit buggy in Audacity 2.1.1 (it is being converted to the new style of effect and will hopefully be fully operational in the next Audacity release). The main problem with it is that it does not remember its last used settings, so you have to select or create the curve that you want to use each time that you use the effect. The imported curve should be remembered correctly (you only need to import it once), but you will need to select it each time.