You can find detailed information on audio bit-depth here. Having the bit-depth set to 24 bit will slightly improve audio quality.
Increasing Sample Rate without having a source that’s sampled at a higher rate won’t improve sound quality, in fact, it might degrade it.
Selecting more channels than the number of speakers you have connected won’t enable you to hear more sounds or hear the footsteps and positioning of enemies better in games. For a 5.1 audio system select 5.1 Speaker.
Under Speaker Configuration select the number of speakers that you have.In sound card application settings (Realtek HD Audio Manager, Realtek Audio Console):
