Set up external speakers for stereo or surround sound in Audio Midi Setup on Mac
Set up external speakers connected to your audio device for stereo or multichannel output, such as 5.1, 6.1, or 7.1 surround sound. For audio devices with multichannel setups, select the speaker used to play each channel.
Tip: Make sure the speakers are connected to your audio devices. Also make sure your audio devices have any required software installed, are connected to your Mac, and are turned on.
In the Audio MIDI Setup app on your Mac, select the audio output device in the list, then click Configure Speakers.
If you’re using an interleaved device with more than one audio stream, select the audio streams you want to use with your speaker configuration. If the stream you select provides enough channels for the speakers you’re configuring, you can’t select additional streams.
Choose the type of output you want to set up from the pop-up menu.
If your setup has five front speakers and two rear speakers, choose 7.1 Surround. If your setup has three front speakers and four rear speakers, choose 7.1 Rear Surround.
For each speaker in the configuration, choose a channel from the pop-up menu below the speaker.
Click the speaker to hear a test tone.
For surround-sound setups, the test tone for each speaker should be the same volume when heard from the listener’s vantage point. You can adjust the volume for each speaker channel in the Audio Devices window.