You can actually see used A2DP codec in iOS device's console.
Step-by-step guide:
- Connect your iOS device to your Mac, answer Trust on the iOS device if you haven't done this before.
- Open Console.app.
- Select your iOS device on the left sidebar.
- Type
bluetooth
in the top-right search bar, press Enter and selectSubsystem
instead ofAll
: - Now, start playing to your bluetooth headphones on the iOS device (codec activates only when you output sound).
- Press
Cmd+F
and search forStarting a2dp send thread
in your console messages: - You'll see used codec in
codec:
field. Values are the same as specified in Bluetooth specs (example). Basically0 = SBC
,2 = AAC
.
Was very surprised, though, that a pair of headphones I just bought from very adored and award-winning manufacturer (not Sennheiser) does not have AAC codec in them, despite having that in specifications (will not name them here, contacting their tech support for clarification).