Balances Game vs. Voice audio. Turn left for more game sound; turn right to hear your teammates better.
Given that this manual is likely for a device released around 2016-2019, you might wonder if you should replace it.
Plug your A40 headset into the dedicated port on the front of the MixAmp. Windows Audio Settings:
To load these: Connect Mixamp > Open ACC > Click "Custom" slot > Adjust sliders > Save to device.