9.How to use the JM21 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 JM21->Pair new device to complete the connection.

What can be done if the JM21 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 JM21 to start the connection.

What Bluetooth codecs does the JM21 support? And how to switch the Bluetooth codecs?

The JM21 supports LHDC, LDAC, aptX-HD, aptX, AAC and SBC which can be switched on Settings->Audio->Wireless playback quality menu. Note that it needs to be disconnected and reconnected to enable the new codec after changing it.

What can be done if the volume is too low when the JM21 is connected to AirPods?

1. Go to System Settings-Audio and find the Bluetooth volume adjustment mode.

2. Switch the volume adjustment mode to Sync Bluetooth volume.

3. Disconnect and reconnect the Bluetooth device.