Controlling Volume with AirFlyUpdated a year ago
To control the volume on the AirFly SE, press the Volume Buttons up or down. To MUTE AirFly SE, double-click the Volume Down button. The light will blink amber continuously to let you know the Volume is muted. Double-click Volume Down again to unmute AirFly SE and return it to the previous volume setting.
AirFly Pro and AirFly Duo do not have volume control. Just like any Bluetooth transmitter, the volume is controlled by the source device. So just set the volume where you want it on the device from which you're transmitting (i.e. the device into which it's plugged). Interesting note: even most Bluetooth headphones that have volume control are actually controlling the volume of the source device.