Change the sound output settings on Mac
You can play sound through your computer’s internal speakers, your display’s speakers (if it has speakers), or through speakers, headphones or other equipment plugged into your Mac or available wirelessly through AirPlay.
On your Mac, choose Apple menu > System Settings, then click Sound in the sidebar. (You may need to scroll down.)
Click Output on the right, then select the device you want to use in the list of sound output devices.
All sound output devices available to your Mac are listed, including the computer’s internal speakers, devices plugged into your computer’s sound port (), USB speakers and AirPlay devices.
For any device plugged into the computer’s sound port, choose Headphones.
Do any of the following to adjust your sound output settings:
Adjust the volume: Drag the Output volume slider.
If you have Sound in the menu bar, you can turn the volume up or down from anywhere.
To set a volume for alert sounds, drag the Alert volume slider in Sound Effects. The alert volume is relative to your computer’s volume, so if you lower the computer’s volume, alert sounds also play more quietly.
Stop sound output: Select the Mute tickbox.
Adjust the balance: Drag the Balance slider.
Depending on your Mac and the devices you use, you may be able to set other volume options using the Audio MIDI Setup app.
If you use apps that have volume controls (for example, Music or iMovie), their settings can only be equal to or less than the computer’s output volume. They don’t override what you choose in Sound settings.