Solution:
1.Xiaomi Karaoke Microphone supports volume adjustment function, short press the switch button (MIC volume adjustment & accompaniment volume adjustment), then volume up or volume down, different mode sound will also be different, you can also try to switch. (MIC volume adjustment & accompaniment volume adjustment), then volume up or volume down, different modes of sound will also be different, you can also switch to try.
2.the microphone is connected to the phone after the default for the phone's volume, in adjusting the microphone volume, you can adjust the phone's volume at the same time The size of the phone can be adjusted simultaneously.
Note: If the accompaniment volume vocal is small, you need to press the switch button to prompt "eliminate the original sound off" in order to hear the normal sound.

Does it help?