Configure Audio on Arch Linux
Audio on Arch Linux should work out of the box unless the desired device is muted. The only thing that is required to get sound working is to unmute the desired channels and set the audio levels with ALSA. Optionally PulseAudio can be configured for multi application use.
Install ALSA
Install from official repository.
sudo pacman -S alsa-utils
Run ALSA Mixer.
sudo alsamixer
Hit F6 and select the sound card you plan on using. Use left arrow and right arrow keys to navigate to the channels that need to be modified. Press m to toggle between mute or unmute of the channel. For S/PDIF you just need unmute but for analogue audio you also need to unmute all desired channels as well as optionally setting the channel volume levels using up arrow and down arrow keys.
Install PulseAudio
This is an optional component that acts as a proxy to existing audio components. It allow multiple applications to output audio. This is desirable for Linux Desktops or standalone applications like Kodi or Steam. Don’t install it unless it is need as it can cause some issues.
Install from the official repository.
sudo pacman -S pulseaudio
Install multilib package from the official repository.
sudo pacman -S lib32-libpulse lib32-alsa-plugins
32-bit packages on a 64-bit system are only required for 32-bit applications most notably Steam.