There should be an Equalizer for the Desktop version of Spotify.
Since Spotify's mobile apps now have an EQ setting, this should be implemented on the desktop version, too! The EQ should come with various presets but also the ability to save your own custom settings.
Hey folks, we know the idea for an equalizer in the Desktop app is a popular request. While we're marking this as 'Not Right Now' please know we're continuing to watch the kudos and comments here in the Community and we're bringing them back to Spotify. Keep an eye here for any updates, thanks!