- Apr 12, 2001
If you connect your Mac to an external display, you may find that the Mac's on-screen and keyboard volume controls are disabled. That's because HDMI, DisplayPort, and Thunderbolt connections carry a fixed volume digital audio signal, so the external device (in this case, a monitor) controls the sound level.
This can be frustrating if the volume controls on your external display are concealed in the bezel or buried in a fiddly on-screen menu. Fortunately, it is possible to re-enable your Mac's native volume controls and use them to adjust the sound level coming out of your monitor's speakers. The steps below show how it's done, although you will need administrator privileges to follow them.
Click here to read more...
Article Link: How to Use Your Mac's Media Keys to Adjust Speaker Volume on a DisplayPort, HDMI, or Thunderbolt Monitor