How to set the system ringtone:
Enter the settings-sound and vibration/sound, vibration and silent key/sound-and you can set the incoming call ringtone, information ringtone, calendar reminder ringtone, notification ringtone, alarm ringtone and so on.
Custom ringtone setting method:
Enter I Music, press and hold the selected song in the music playlist, and choose to make ringtones. (Ringtones are saved in the "Make Ringtones" folder in file management. At present, there are only two formats that support ringtone production: MP3 and WAV.