MIUI is Xiaomi's custom skin for Android, and incorporates a default audio app called MiSound. This may be handy; however, it has historically lacked an equalizer (or EQ) to adjust music playback to taste or genre. However, developers familiar with this OS' latest version claim to have found one in a new update.
https://www.notebookcheck.net/Xiaomi-may-be-working-on-an-inbuilt-equalizer-for-MIUI-11.448622.0.html