To provide a system where the aperture area of a bass reflex duct and the horn shape of a sound guide are freely changed with a simple structure in the speaker system provided with a sound guide and a bass reflex duct.

Part of a housing 21 is provided with a baffle plate 21a, a sound guide 21b, and a bass reflex duct 21d, and they are formed integrally. The sound guide 21b and the bass reflex duct 21d extended outward from the baffle board 21a are respectively terminated at openings 21c, 21e and directed in the same direction. A housing cover 23 being parts of the housing 1 covers a housing main body. The speaker 4 is fixed to the baffle board 21a and a cabinet 25 with a rear box being its part is fixed to the housing 21. The shape of a barrier 6 that parts the sound guide and the bass reflex duct and that acts like a sound guide control member can be changed so as to change the shape of the horn and the aperture area.