You can either choose a default playback quality on your various apps but also change the quality while listening to your music
Webplayer and desktop app:
Go to your profile by clicking on the top right of your screen, then on the tab “Music Playing” to select your default listening quality.
While playing a track, you can change the listening quality in the player at the bottom of the screen. Your new default listening preference will also be changed in your account’s settings.
Click on My Qobuz on the bottom left of the screen and then go to your settings by clicking the cogwheel icon at the top-right. Go to the streaming tab to choose your default listening quality. You can distinguish between your preferences for listening on Wi-Fi and mobile data.
You can also change the listening quality while playing your music.