Looks like it should be mandatory: https://en.wikipedia.org/wiki/SBC_%28codec%29 https://en.wikipedia.org/wiki/SBC_%28codec%29 As of A2DP version 1.3, the Low

Looks like it should be mandatory: https://en.wikipedia.org/wiki/SBC_%28codec%29 https://en.wikipedia.org/wiki/SBC_%28codec%29 As of A2DP version 1.3, the Low Complexity Subband Coding remains the default codec and its implementation is mandatory for devices supporting that profile, but vendors are free to add their own codecs to match their needs.