To access Spotify Equalizer on iOS, you can follow these steps:
1. Open Spotify app on iOS device, navigate to the Your Library tab in the lower-right corner and touch the Setting button at the top-right corner;
2. In the setting window, you need to select Playback and then you will see there is an Equalizer option. Please tap the toggle to turn on the equalizer;
3. You will see a list of preset equalizers for different types of music. You can start to adjust the music preferences to the right one with best sounds by dragging the little white dots;
4. When all settings are ready, just touch a preset to apply them, and you can get back to the home screen and listen to Spotify music in most suitable taste.