Allegro 5 api
#include <allegro5/allegro_audio.h> ALLEGRO_MIXER *al_get_default_mixer(void)
Return the default mixer, or NULL if one has not been set. Although different configurations of mixers and voices can be used, in most cases a single mixer attached to a voice is what you want. The default mixer is used by al_play_sample(3alleg5).
al_reserve_samples(3alleg5), al_play_sample(3alleg5), al_set_default_mixer(3alleg5), al_restore_default_mixer(3alleg5)