Mac Keeps Switching Audio Output? How to Stop It Picking the Wrong Device

A Mac keeps switching audio output because macOS has no priority list. When a new audio device appears, whether Bluetooth headphones, a USB interface or a monitor's HDMI or DisplayPort audio, macOS often makes it the default output. You can stop it for Bluetooth headphones with a setting in System Settings. For everything else you either re-pick the device in System Settings → Sound → Output each time, or use an app with device rules, such as Soundish, to choose a preferred output automatically.

Why does my Mac change its audio output on its own?

macOS treats a newly connected device as the one you probably want. It doesn't remember that you prefer the desk speakers over the monitor. The usual triggers are:

• Bluetooth headphones or AirPods reconnecting when you open the case or wake the Mac.
• An external monitor being plugged in or waking from sleep. Most monitors expose an audio device over HDMI, DisplayPort or USB-C, even if they have no speakers.
• A USB DAC, interface or dock being connected or re-enumerated after sleep.
• A dock or hub that drops and re-adds its audio device when the Mac wakes.

The last two are why the problem often appears "for no reason" in the morning. The Mac woke up and the device list changed underneath you.

How do I stop it with the built-in settings?

There are three things worth trying before you install anything.

1. Set AirPods to connect only when you ask. Connect the AirPods, then open System Settings, click the AirPods name in the sidebar, and find Connect to This Mac. Change it from Automatically to When Last Connected to This Mac. This stops them grabbing your Mac's audio when they are really connected to your iPhone. Other Bluetooth headphones don't have this option.

2. Put the Sound control in the menu bar. Go to System Settings → Control Center → Sound and set it to Always Show in Menu Bar. Clicking it lists every output device, so switching back takes two clicks instead of a trip into Settings. Holding Option while you click the Sound icon is another quick way to reach the device list.

3. Check the monitor's own menu. Some monitors have an on-screen setting to turn off audio over HDMI or DisplayPort. If yours does, switching it off removes the device and the problem with it. Not every monitor offers this, so look in the display's on-screen menu under Audio or Sound.

If none of those help, it's because macOS really doesn't offer a "never use this device" or "always prefer this device" setting. It is not a setting you've missed.

Why does plugging in a monitor make my Mac go silent?

This is the most common version of the problem. You connect a monitor with no speakers, or one with poor ones. macOS adds its audio device and makes it the default output. Your music keeps "playing" but into a device that makes no sound.

To confirm it, open System Settings → Sound → Output. If the selected device is your monitor's name, that's the culprit. Selecting your speakers or headphones again fixes it until the next time the monitor reconnects or wakes.

A related problem is the monitor's volume keys doing nothing because there's no way for macOS to change the volume on that device. That is covered in Mac Sound Output Greyed Out? 6 Fixes That Actually Work.

How can I make the Mac pick the right device every time?

This is where an app helps, because the fix needs a rule rather than a setting. Soundish has output rules for exactly this case. A rule can pick a preferred device whenever it connects, and it can stop a monitor without speakers from becoming the default output. With a rule in place, you plug in the monitor and the sound stays on your speakers or headphones.

Some practical notes:

• Soundish lives in the menu bar and must be running for its rules to apply. If you quit it, macOS goes back to its normal behaviour and everything plays as before.
• Nothing needs installing. There's no driver and no restart. macOS asks once for permission to let Soundish capture system audio, and nothing is recorded or saved.
• It needs macOS 14.6 (Sonoma) or later, on Apple Silicon or Intel.
• It costs $14.99 once, after a 7-day free trial with no card, so you can check whether the rules fix your particular dock or monitor before paying.

If your real goal is different apps on different devices, such as music on speakers and calls on headphones, that is per-app routing rather than a default device. How to Change Audio Output Per App on Mac is the post for that. For a setup you want to switch between in one go, Mac Audio Profiles covers saving and restoring it.

What if the sound goes silent instead of switching?

If the output doesn't change and a USB interface or DAC just stops making sound, that is a different problem from the one above. I've been through it myself. A user's external USB audio interface went silent because the old Soundish engine mishandled 44.1 kHz sample rates, and the fix turned into a full rewrite. I wrote the whole story in The Support Email That Made Me Rewrite Soundish's Audio Engine. If your interface is silent, check its sample rate in Audio MIDI Setup (in /Applications/Utilities) before you blame the output switching.

Common questions

Can I set a priority order for audio devices on a Mac?

Not in macOS itself. System Settings → Sound → Output only lets you pick the current device, and the Mac decides what to do when a new one appears. Apps with output rules, such as Soundish, add the missing preference.

Why does my Mac switch to my monitor's speakers when I plug it in?

Because the monitor reports an audio device, and macOS usually makes a newly connected device the default. Pick your speakers again in System Settings → Sound → Output, turn off HDMI audio in the monitor's menu if it has that option, or use a rule that keeps the monitor from becoming the default.

Can I change the audio output for just one app on Mac?

Not natively. macOS has one system output at a time. Soundish lets you send individual apps to different devices, for example Spotify to the speakers and Discord to the headphones, while the rest of the Mac stays on the default.