While this improves the sound quality and bitrate of the songs you hear through mobile connections, the obvious disadvantage is that more data on your mobile plan is used, so this is a feature that perhaps users is limited IPhone with unlimited data plans.
This works to listen to music of the highest quality possible from Apple Music, iTunes Radio, iTunes Match and songs from an iCloud iTunes library.
How to enable high quality music playback on iPhone
- Open the Settings app on your iPhone and go to "Music"
- Scroll down to "Mobile Data" and move the "High Quality" switch to the "On" position. You may need to enable "Mobile Data Usage".
- Return to the music application and put a station or song as usual. Now the audio will play in the highest quality. Keep in mind that in modern versions of iOS the feature is labeled as "High Quality Streaming" and in older versions it appears as "High Quality on Mobile Phones".