(EN) A small-sized speaker system having extremely excellent bass range reproduction capability comprises a speaker unit provided in a closed box and a sound guide through which sound radiated from the speaker unit is guided into the free space so as to cause compression and expansion of air in an extent greater than that in which the speaker unit is provided in a closed box of the same shape but sound is radiated directly into the free space. The f0 of the speaker system is 20 % or more lower than that of when the speaker unit is provided in a closed box of the same shape but sound is radiated directly into the free space.