Enable AAC and aptX Bluetooth Codecs on Mac
#1 Download Bluetooth Tools
To start, you'll need to have a developer account, click the link to download the appropriate tool to manage your codec libraries Mac Developer Tools. Search for “Additional Tools for Xcode”, the latest version is 9.0.
Extract the dmg and search for “Bluetooth Explorer.app”. Move it into your Application Folder within your Mac.
Bluetooth Explorer
Run the Bluetooth Explorer and then go to Tools -> Audio Options. Enable AAC by clicking on “Enable AAC”. You can also move the AAC bitrate up more to the right if needs be. I moved mine up to 320, which is the furthest. I also enabled "Force use of aptX".
#2 The Terminal Way
Open your terminal add run the following command.
sudo defaults read bluetoothaudiod
If “Domain bluetoothaudiod does not exist” appears, that means you have not set any options. To enable aptX and/or AAC, you can use the following commands and then run the above default command to see if it updated correctly.
sudo defaults write bluetoothaudiod "Enable AptX codec" -bool true
sudo defaults write bluetoothaudiod "Enable AAC code" -bool true