The Output Module in the Audio tab under RV Preferences lists audio interfaces that RV can choose between to handle audio, and is specific to operating systems. Each operating system has its own platform specific option, but fairly recently we created a Qt based cross platform setting named Platform Audio. We encourage you to use this option for Output Module.
The Output Format and Rate configuration is an important setting, and you should choose a reasonable format and rate for the audio contained in the sources you most commonly review. Most of the time this is 32-bit float and either 44.1 or 48 kHz.
Using “Keep Audio Device Open When Not Playing” will help reduce slow down and pops when looping playback or when starting and stopping frequently. However, in some Linux distributions this can conflict with other applications using the audio system. Using “Hardware Audio and Video Synchronization” may help keep your media synced during playback, but could introduce small delays for the two systems to line up when starting playback.