11. How to use the M17 as a Bluetooth transmitter?

It is similar to the mobile phone's. Here are the instructions.

1. Go to the Settings->Bluetooth menu to turn on the Bluetooth function.
2.Make the Bluetooth receiving device, such as Bluetooth earphones, enter the pairing state. (Please refer to the user manual of the Bluetooth receiving device about how to enter pairing state.)
3.Go to the Bluetooth device list of the M17->Pair new device to complete the connection. 

What can be done if the M17 fails to connect to Bluetooth earphones?
If it fails to connect to Bluetooth earphones for the first time, please make sure the earphones are under pairing state (the connection will fail if the earphones are under reconnecting state for the first-time connection). Go to the Bluetooth menu of the M17 to start the connection.

What Bluetooth codecs does the M17 support? And how to switch the Bluetooth codecs?
The M17 supports LDAC, aptX-HD, aptX, AAC and SBC which can be switched on Settings->Audio->Wireless playback quality menu. 

What can be done if the volume is too low when the M17 is connected to AirPods?
Go to Settings->About phone, and continuously tap the "Build number" 7 times. Go back to Settings->System->Developer options menu to turn off the"Disable absolute volume". Disconnect and reconnect the two devices through Bluetooth.