How to Use Audio MIDI Setup on a Mac

Before you start

Audio MIDI Setup is a built-in macOS utility for managing audio devices and MIDI devices connected to a Mac. It runs locally and shows two main categories: audio devices, such as microphones, speakers, headsets and camera inputs, and MIDI devices, such as keyboards and controllers. You can use it to choose an input or output device, change the sample rate, check levels and control how audio is routed.

Before opening the utility, connect the microphone, camera, interface or MIDI controller you want to configure and make sure it is recognized by the system. Many USB audio devices are bus-powered and should appear soon after connection. Devices that require a driver may need the manufacturer's current version for your macOS release. Closing apps that are using the device can help when you need to change formats or routing.

Step-by-step instructions

Open Audio MIDI Setup from Finder or Spotlight. One practical way is to open Spotlight with Command-Space, type Audio MIDI Setup, and press Return. You can also find it in the Utilities folder inside Applications.

If the Audio Devices window opens blank, choose Show Audio Devices from the Window menu. Use the sidebar to check that the connected microphone, camera or audio interface is present. Select an audio device to view its current input and output configuration.

To adjust an input device, select it in the sidebar and check the controls on the right. The Input tab shows available channels and an input level meter. Speak into the microphone or play audio into the selected input and confirm that the meter moves without staying in the red area. If the control is available, drag the input level slider to reduce clipping or raise a weak signal.

To adjust an output device, select the device and use the Output tab. The Master Stream section may allow stereo channels and output volume settings. Use the speaker icon to test routing while audio is not being recorded, and be ready to lower the volume because the test tone can be loud.

The Format menu controls sample rate and channel configuration for many devices. A match between the sample rate set here and the rate used by your recording or call application can prevent unwanted conversions. Common values include 44,100 Hz for ordinary speech and media, or 48,000 Hz when working with video call tools and video production.

To create one combined audio device from several microphones or interfaces, choose Create Aggregate Device from the Audio Device window's action menu. In the aggregate device settings, enable the required inputs and outputs and choose a clock source. Keep in mind that aggregate devices can change which device supplies timing, so the result should be checked after creation.

Check the output

The quickest verification is to leave Audio MIDI Setup open and watch the meter for the selected input device while you speak or play audio. A visible but controlled level usually means the device is being received by macOS. For an output device, play ordinary sound and confirm that the selected output does not play through an unexpected speaker.

For sample rate changes, compare the value shown in Audio MIDI Setup with the value selected in the app you are using for recording or a call. Some apps manage their own audio format and may still request a different rate. The utility also shows physical formats for some devices, so a mismatch can indicate that the connection needs to be re-selected.

Common problems and next steps

If a USB microphone is missing, reconnect it to a direct port rather than an unpowered hub, then close and reopen the utility. A device that appears in System Information but not in Audio MIDI Setup often needs the correct driver or privacy permission. On newer macOS versions, open System Settings, then Privacy and Security, and check whether the microphone is listed as available to the app you are testing. The controls shown here may differ by macOS version, so verify the path on your system.

If an input or output device is present but no sound is captured, first confirm that the device is selected in both Audio MIDI Setup and the calling or recording app. Raise the input level gradually while watching the meter, and reduce background noise such as fans or nearby conversations. When a device uses its own gain dial, set it to a moderate position before adjusting macOS controls.

For a device that appears disabled, select it and check whether another app is holding it at a different sample rate. Quit that app before changing the format. If audio can be recorded but not heard, check the output device selected in the same window and try the speaker test button. After changing a physical connection, reopen the relevant window so the utility refreshes its device list.

Use the Aggregate Device settings when a call or recording app can only choose one interface but you need audio from two devices. If timing problems occur, move the device that must provide the clock to the top of the subdevice list or set the clock source explicitly. After making changes, test with the application you actually intend to use instead of relying only on the system utility.