Kodi Basic Sound and Audio Settings There are 2 different menus that you can use to modify audio settings: A. Kodi audio settings:
Audio output device: Here you can select which one of the audio outputs from your computer you will be using. Depending on what you select here, some settings further down might be enabled or not.
Number of channels: If your audio connection is digital, this represents the channels supported by the audio connection; if it’s analog, it will represent the number of speakers your system is using.
Output configuration: You can set this option to Fixed, Optimized or Best Match. This will let you know if properties such as sampling rate and speaker configuration will change during playback to match the source (which is done in Best Match setting); will be set at the start of playback and not change (corresponds to Optimized); or will be set by the value indicated in settings at all times (which would be the Fixed option).
Limit sampling rate (kHz): If you set fixed output, this indicates the sampling rate. If you are using SPDIF, this is the maximum sampling rate.
Stereo upmix: When enabled, it lets 2-channel audio be upmixed to the number of channels set in Kodi audio settings.
Normalize levels on downmix: Also can be called Maintain original volume on downmix. When enabled, keeps the volume of the stream, at the cost of compressing dynamic range. When disabled, volume will be lower but the dynamic range will be maintained. Keep in mind the dynamic range is defined as the difference between the quietest and the loudest sounds in an audio source; thus, you should enable this setting if the dialogue in movies is barely audible.
Resample quality: If you need to have audio sampled at a different rate than the source, this is the option you need to tweak; you can set it on Low, Medium and High, but the latter two will consume more computer resources.
Keep audio devices alive: Defines the time audio devices will wait before entering a suspended state. It also has Always (audio devices never suspended) and Off (audio devices always suspended) settings. This setting uses a lot of CPU resourses, so depending on your hardware it might not be available.