Android 6

The Android 6.0 Compatibility Definition enumerates the requirements that must be met in order for devices to be compatible with Android 6.0.

Audio formats

Android 6 requires support for AAC, MP3 but also FLAC, Vorbis and Opus. WAV is supported as well.

The minimal requirements are 16 bit/44.1 kHz.

Latency

One of the complains about Android audio has been the latency. It is to high for professional (recording) use. Android 6 addresses this.

USB

Android6 devices should support USB host mode.

The USB host mode MUST implement the USB audio class.

This is crucial if you want to use an external USB DAC.

 

References
Android 6.0 Compatibility Definition