docs/src/configuration/audio.md
On most setups, audio should be Just Working™. If you have specific needs or something's not working, you might need to touch some of the config values.
-b/--backendorbackendin the config file.
There are different audio backends available to choose from. See spotifyd --help to get the available names.
--deviceordevicein the config file.
Instead of using the default device, which can sometimes be different to what you'd prefer, you can ask spotifyd to use a specific audio device. The interpretation and available values depends on the backend you're using.
aplay -L to get a list of possible devices.pactl list short sinks to get a list of possible names.
-B/--bitrateorbitratein the config file.
To reduce bandwidth usage or increase quality, you can play with the bitrate.
--volume-controllerorvolume_controllerin the config file.
In most cases, leaving this at the default (softvol) should be fine.
If you want your spotifyd volume to be synchronized with an output device's hardware volume, you can set this to alsa or alsa_linear. In both cases, you might also want to set the mixer device to set which device's volume should be changed.
If you want to prevent the user to be able to adjust the volume, set this instead to none.
For more interesting but less relevant audio options, have a look at spotifyd --help or the example config.