How to Adjust Master Volume in Audio MIDI Setup

Before you start

Audio MIDI Setup is a built-in macOS utility for viewing and configuring audio devices. It runs locally on the Mac and does not require an online service. The master volume controls shown in this window depend on the selected audio device and its driver, so the available options can change when you switch devices or connection types.

Connect the audio device you want to adjust before opening Audio MIDI Setup. For external interfaces, speakers, or microphones, use the manufacturer's current driver or the class-compliant connection supported by macOS. Close any apps that may be using the device if you plan to change the output format or sample rate.

Step-by-step instructions

Open Audio MIDI Setup from the Utilities folder inside Applications, or use Spotlight to search for it. In the sidebar, select the output device that you want to control. The sidebar may list devices under headings such as Built-in Output, external interfaces, or aggregate devices.

Look for the device controls on the right side of the window. If the selected device supports hardware or driver-level volume control, you may see a master volume slider or a channel volume section. Move the slider to change the output level. On some devices, the control may be labeled Volume, Master, or Output.

A master volume slider is not available for every device. Some audio hardware does not expose volume control through Core Audio, or the driver disables it. In that case, use the physical volume control on the device, the volume buttons on the Mac keyboard, or the output volume in the app playing the audio.

Select the output device and open the device settings if you need to change its output stream. The Format menu may show options such as 44.1 kHz, 48 kHz, 96 kHz, or higher, depending on the hardware. Changing the sample rate affects how the Mac sends audio to that device, not the listening volume directly.

For a device with multiple output channels, the channel table can show separate level controls for each channel. Adjusting channel levels changes the balance or output from that channel. Make a note of the original values before changing them if you want to return to the previous configuration.

Check the output

Play a short audio file or a test sound while Audio MIDI Setup is open. The level change should be audible immediately if the control is active. Move the slider gradually and listen for clipping, distortion, or sudden jumps in loudness. If the macOS output volume is also available, check whether it is set too low or muted.

Open System Settings and select Sound, then Output. Confirm that the expected output device is selected and that the system output volume is at a usable level. Audio MIDI Setup shows device routing and format controls, but the main listening level may still be controlled by macOS or the connected hardware.

If the device supports an input signal, check the Input tab or the input section for the selected device. The input level is separate from master output volume and should not be changed as a substitute for output level. A high input level can add background noise to recordings even when the output sounds correct.

Common problems and next steps

No volume slider appears in Audio MIDI Setup. This usually means the selected device does not expose a Core Audio volume control. Set the level from the device itself, from macOS Sound settings, or from the app that is currently playing or recording audio.

The slider moves but there is no change in loudness. The device or driver may not apply the control, or the Mac may still be using another output device. Select the correct device in System Settings and check whether the physical output or interface has a separate monitor level.

Audio is distorted after increasing the level. Reduce the output volume and lower any boosted channel levels. Distortion can also occur if the sample rate does not match the device format or if the connected speakers or headphones have their own gain set too high.

The output changes back after restarting or reconnecting the device. Some drivers restore their own saved volume state. Set the preferred level on the hardware or in the manufacturer's control app, then check whether macOS and the app retain the same output device and volume after a restart.