LS Filter

LS Filter is a plugin for Audacity that was developed to help certain seasoned computer users such as music creators, sound engineers or hobbyists enhance their music projects by letting them select filters and adjust a bunch of parameters related to them in a quick, effortless manner.

Installing the plug-in might seem a bit difficult at first, since you have to move the DLL file into Audacity's "Plugin" folder, launch Audacity, access the "Effect" menu, select the "Add / Remove Plugins" option from the list, then select LS Filter from the list and hit the "Enable" button. However, it sounds way more complicated than it actually is.

Once you get it up and running, you'll notice that the main window comes with three slider bars and multiple buttons. The first slider bar lets you choose the filter type, the second one enables you to modify the cutoff frequency value while the third one lets you set the resonance level from 0.0 to 1.0.

You can also start playback from the same window, skip backward or forward, enable or disable this plugin, save the preset in order to use it later from the "Manage" menu and even enable a latency compensation by opening the "Options" window from the same "Manage" menu mentioned above.