Proxy Audio Device

About

Proxy Audio Device is a HAL virtual audio driver for macOS that sends all output to another audio device. Its main purpose is to let you use macOS's system volume controls, such as the menu bar volume icon or the volume keyboard keys, to change the volume of external audio interfaces that don't support it. The project notes it may also be useful for other purposes.

It can be installed with Homebrew (brew install --cask proxy-audio-device) or MacPorts (sudo port install proxy-audio-device), or manually by moving the ProxyAudioDevice.driver into /Library/Audio/Plug-Ins/HAL. After installation, the Proxy Audio Device Settings app is used to set the proxy output device's name, the output device the driver proxies to, and the size of its audio buffer. Core Audio must be restarted or the system rebooted after installation or removal.

If the audio buffer is set too small, the driver may produce pops, crackles, or distortion, and increasing the buffer size is the suggested fix. Possible future work includes an indicator in the settings app for buffer overruns, support for proxying more than two channels of audio, and the ability to create more than one proxy device.