Judging by the genres represented in my iTunes library, I listen to a wide variety of music, from alternative, blues, and country to R&B, reggae, and rock, with a bit of electronica/dance, hip-hop/rap, and jazz in between. I don't always adjust iTunes's equalizer, but when I do, I find it helps. For the last year or so, however, I've switched from using iTunes to Spotify for the majority of my listening pleasure. I love Spotify's seemingly limitless library and its ability to load in a fraction of the time it takes iTunes, but one thing that's missing is an equalizer. Thankfully, Ghacks pointed me toward Equalify, a free but Windows-only app that adds a 10-band equalizer to Spotify.
You won't find Equalify listed among Spotify's apps in the Spotify app itself. Instead, close Spotify and install Equalify from its Web site. Then open Spotify again and you'll see a small EQ button to the right of the search bar. Click on the button to open Equalify. After clicking the on-off button to enable the service, you can adjust any of the 10 sliders. And from the Preset button, you can select and modify 14 presets. You can also save your own presets if you find an arrangement that works best for your audio setup.