MBP: aptx or aptx-hd via bluetooth?

[ducatiti]

I just noticed that when my Bluetooth headphones are connected, it is using aptx (holding option and clicking on Bluetooth connection).

That being said, would this be aptx or aptx-hd? My headphones are capable of aptx-hd but I'm not sure if I am using its full potential.

Thank you.

 

[ducatiti]

Also, is there a way to force the MBP to use AAC instead of aptx? I just find the volume and sound quality is not that good with aptx.