Provided by: allegro5-doc_5.0.10-2_all 

NAME
al_attach_mixer_to_mixer - Allegro 5 API
SYNOPSIS
#include <allegro5/allegro_audio.h>
bool al_attach_mixer_to_mixer(ALLEGRO_MIXER *stream, ALLEGRO_MIXER *mixer)
DESCRIPTION
Attaches a mixer onto another mixer. The same rules as with al_attach_sample_instance_to_mixer(3alleg5)
apply, with the added caveat that both mixers must be the same frequency. Returns true on success, false
on error.
Currently both mixers must have the same audio depth, otherwise the function fails.
SEE ALSO
al_detach_mixer(3alleg5).
Allegro reference manual al_attach_mixer_to_mixer(3alleg5)()