With Custom Equaliser (EQ), you can use sliders to adjust five different frequency bands and save your preferred settings. You can also pick one of the presets, like 'Heavy bass' for a starting point. These settings do not apply to phone call audio.
Custom Equaliser
On a Pixel phone with Android 10+: Go to Settings 
On other Android devices: Open the Google Pixel Buds app 
- Tap Sound
Equaliser (EQ) settings
.
- Move the sliders to adjust each frequency or pick a preset from the list.1
.Presets
You can pick one of the following presets as a starting point to get audio that works for you.
- Default: Google-tuned to work best across all types of audio content
- Light bass: Reduces bass to highlight everything else
- Heavy bass: Boosts lower frequencies to put bass first
- Balanced: A more neutral sound that balances the instruments in all ranges
- Vocal boost: Makes vocals stand out
- Clarity: Boosts the highs for better understanding of the words in speech and more sparkle and brilliance in music
- Last saved: Restores your last saved equaliser setting
1Pixel Buds must be connected to the phone to activate this feature.