How do I change USB Audio Class Mode?

USB mode:
A4 on – Puts the CXA in USB Audio Class 2 mode.
A4 off – Puts the CXA in USB Audio Class 1 mode.

Notes:
To save the setup settings and exit the setup menu, press the Speaker A/B button.
Pressing the Standby/On button while in the setup menu will exit this setup menu and will not save the setup settings.