Spotify offers a range of audio qualities to users who may be looking for the clearest audio possible or audio that sips data rather than gulps it. Unfortunately, you can't separately set the audio quality while streaming on mobile data — it uses the same audio quality setting as streaming on Wi-Fi. So before you crank your streaming audio quality up to "Extreme", consider how much you intend to use Spotify with a data connection, such as in the car or while working out.
To set your quality, go to
My Library and tap the
gear icon in the top right corner; the audio settings are about halfway down the menu.
If you're looking for good audio quality without kissing your data caps goodbye, there's still some good news, if you can plan ahead. You can set the audio quality for downloaded music separately from streaming audio quality. Unless your phone is already lacking storage space, I recommend setting downloaded audio quality to Extreme and loading up for listening while on the go.
Source : https://www.androidcentral.com/top-5-spotify-tips