For a better equalizer

One of the CoMETE project this year was to improve the current Equalizer.

Currently, the Songbird/Nightingale Equalizer only allow to fiddle with buttons and it’s pretty much it. I did in the past an add-on for Songbird to add basic presets support and recently Brice Santus from Evry added the ability to save your own presets in Nightingale.

For techies, your presets are saved in a XML file inside your profile folder, so you can easily copy it :)

For now, the improved equalizer is available as an add-on for testing purposes, but it’s going to be shipped by default on a future Nightingale version.

So please test it, report any bugs on the GitHub issues page, and also tell us how to improve it !