Please note, that your playback device supports a audio codec which exceeds the default SBC codec.
Byron wireless features Qualcomm® aptX™, Byron BTA features Qualcomm® aptX™ and AAC.
You can find the info which codecs are supported by your playback device in the data sheet of the respective playback device. Usually high-quality Andrdoid devices support Qualcomm® aptX™, whereas Apple devices support AAC. (All support SBC.)
Playback devices and Byron wireless and BTA agree automatically on the highest quality codec available.
Addionally, we recommend to raise the volume level on the playback device to the maximum and control the actual playback volume on the headphone only.