al_set_mixer_frequency - Allegro 5 API

       Set the mixer frequency (in Hz).  This will only work if the mixer is not attached to anything.

       Returns true on success, false on failure.

       al_set_mixer_frequency - Allegro 5 API

al_get_mixer_frequency(3alleg5)

Allegro reference manual                                                         al_set_mixer_frequency(3alleg5)

              #include <allegro5/allegro_audio.h>

              bool al_set_mixer_frequency(ALLEGRO_MIXER *mixer, unsigned int val)