Set Custom Audio Balance for Mono in macOS 13

macOS 13 Ventura allows you to set a custom audio balance while outputting mono sound. By combining the system's accessibility mono audio feature with the master balance slider, you can sum stereo channels into a single mono track and adjust the volume independently between your left and right speakers or headphones.

How Mono Audio Balance Works in macOS 13

When you enable mono audio in macOS, the operating system combines the left and right audio channels into a unified signal sent to both outputs. Adjusting the balance slider does not alter channel content; instead, it shifts the relative volume of this combined mono signal between the left and right sides. This setup is particularly useful for users with unilateral hearing loss who require full audio content delivered at different volumes to each ear.

How to Enable Mono Sound and Adjust Balance

You can configure both settings natively within macOS 13 System Settings:

1. Click the Apple menu () in the top-left corner of the screen and select System Settings.
2. In the sidebar, select Accessibility, then click Audio in the right-hand pane.
3. Toggle the switch next to Play stereo audio as mono to the On position.
4. From the left sidebar, navigate to Sound.
5. Under the Output section, ensure your desired output device (e.g., Internal Speakers, Headphones) is selected.
6. Locate the Balance slider below the output volume controls and drag it left or right to set your preferred volume offset.

The changes take effect immediately across all system sounds and media playback.

Advanced Customization

The native balance slider applies globally to the selected output device. If you require per-application balance control, independent equalization alongside mono downmixing, or precise decibel-level balance offsets, third-party audio routing utilities such as Rogue Amoeba's SoundSource provide deeper mixer-level configuration for macOS 13.