Adding volume control to unsupported devices

When connected to a Mac, many audio output devices fail to provide proper volume adjustment. Displays connected via HDMI or DisplayPort, as well as many other non-standard digital devices, simply offer no output controls. As a result, MacOS won't let you adjust the volume level for these devices, and the volume keys on your keyboard won't have any effect.

Our audio control utility SoundSource works behind the scenes to provide volume adjustments for all audio devices. This makes it possible to control the volume levels for any audio output, even those that don't allow it by default.

Basic volume control

When SoundSource is running, it's possible to adjust the volume level heard through output devices which ordinarily offer no volume control. Even when such a device is set as the system output, the slider in SoundSource's main window will adjust the levels heard through the device.

Just move this volume slider up or down to adjust the volume level heard through the device.

Make keyboard volume keys work too

Ordinarily, when using an audio device with no default volume control, pressing the keyboard's volume keys will result in no change to what you hear. Instead, this frustrating on-screen display is shown, indicating the volume level can't be changed:

From frustration…

With SoundSource's Super Volume Keys feature, this limitation is removed. Just activate Super Volume Keys in SoundSource, and your keyboard volume keys will work exactly as you expect, adjusting volume levels up or down.

…to success!

Activating Super Volume Keys

To turn on Super Volume Keys, open SoundSource's Preferences window, and turn on the Super Volume Keys checkbox. Your keyboard volume keys will then be able to adjust any audio device you set as the System Output.

Note: When you first activate Super Volume Keys, you need to perform a one-time authorization giving SoundSource access to control your Mac via the Accessibility controls. Read this article for full instructions.


When SoundSource is running, it provides full volume control for all your audio output devices. This includes the ability to use your keyboard's volume keys with any device. If you play audio through a hardware device that does not ordinarily provide volume control, SoundSource is here to assist.