Library Player uses only one sound card, and uses the default sound card for audio playback selected in Windows settings. Before making any changes to your computers sound card settings, it is recommended that you first close any currently running copies of Library Player.
You can adjust audio levels on the computer's sound card using the Windows Volume Control – however when using the software within a broadcasting environment your staff will most likely adjust audio levels using a mixing desk.
Library Player's mixer (which you can access from the Playlist menu) does not change any settings for your computer's sound card, including the audio levels set in Windows Volume Control.