Yamaha RM-CR Reference Manual page 16

[For macOS]
Open the [Sound] preferences, and then confirm that [Yamaha RM-CR] is selected on the [Output] and [Input] tabs. Otherwise, click
[Yamaha RM-CR].
NOTE: Adjust the microphone sensitivity (input volume) as necessary. The adjuster is available on the [Input] tab.
RM-CR Reference Manual
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