How to adjust the volume on the Leitner wireless when using a Mac Microphone: We can adjust the mic volume underneath the headset charging base with all Leitner wireless headsets (the lowest setting is best when paired via Bluetooth with SmartSet). Listening: If we are connected via USB to the Mac we can only adjust the listening volume on the headset. If we are paired up via Bluetooth to the Mac we can adjust the listening volume on both the headset and the computer.