24. Why some tracks cannot be played through Bluetooth on the X1 2nd gen?

A: The below formats and sample rates are currently not supported when output through Bluetooth because of the incompatiblity. 

APE: Fast:     16bit-64kHz or above

                      24bit-48kHz or above 
         Normal: 16bit-48kHz or above
                      24bit-48kHz or above
         High: 16bit-48kHz or above
                   all sample rates at 24bit
        Extra High: all sample rates
        Insane: all sample rates

ALAC:    16bit-96kHz or above
              24bit-96kHz or above
              32bit-96kkHz or above

FLAC:     24bit-176kHz or above

M4A：48kHz or above (with HE-AAC codec)

OGG: 16bit-96kHz or above

WAV：24bit-172kHz or above
            32bit-96kHz or above
            all sample rates at 64bit

WMA: 24bit-88kHz or above


We will try our best to improve the Bluetooth function and make it more compatible in the future. Sorry for any inconvenience this might bring to you.
The above result applies to firmware v1.5.3.