Do you need to change the speaker or headphones through which your Mac plays sounds? Changing the sound output device on your Mac is super easy—you'll just need to make a quick change in your System Preferences. Note: You'll need to have another output device connected in order to change to any option other than the default speakers.
Open your Mac’s System Preferences.
Click the Apple menu and select System Preferences.
The Apple menu is at the top-right corner of the screen.
Click the “Sound” icon.
The Sound icon looks like speaker.
This opens your sound settings.
Click “Output.”
This tab is at the top of the window.
Your output settings will appear.
Select an output device.
Choose the device you want to hear audio from in the list.
This highlights the device.
Customize your device settings.
Adjust the volume and balance.
Click and drag the white notch under “Balance” to adjust your balance settings, and the white notch under “Output volume” to change volume settings. Your new settings will take effect instantly.