A sound-wave path-length correcting structure for a speaker system includes a sound source and a horn. The horn has a sound-wave path-length correcting throat portion. The sound-wave path-length correcting throat portion corrects a sound-wave path-length of a sound wave input from an inlet opening thereof in the sound path, and emits the sound wave from an outlet opening thereof. The sound path is defined by a first side surface with a concave curved surface and a second side surface with a convex curved surface that face each other with a space, and a third side surface and a fourth side surface that face each other with a space. The third side surface and the fourth side surface are formed so that their surfaces gradually widen as the surfaces advance from the inlet opening to the outlet opening of the sound-wave path-length correcting throat portion.