When Meizu's mobile phone is talking, you can hear the sound when you turn on the speaker, but you can't hear the sound when you turn off the speaker. Why?
The volume can be adjusted through the volume key on the side of the phone. It is worth noting that the volume is the same when the phone is in different states. For example, the media volume is adjusted when playing games, and the system volume is adjusted when the phone is in standby mode. Enter Android Optimization Master - Quick Settings - Sound Display Settings - Phone volume control, you can control the ringtone volume, notification volume, media volume, alarm clock volume, call volume, system volume