<p>A loudspeaker unit (2) of a loudspeaker system (1) is fitted to a cabinet (4) . An absorbent (3) is disposed in a hollow chamber (R) inside the cabinet (4) and absorbs a gas inside the hollow chamber (R). A phase inverting mechanism (8) inverts the phase by resonating with a sound of a specific frequency radiated from the loudspeaker unit (2) into the hollow chamber (R) and radiates this sound to outside. The watertight means of the phase inverting mechanism (8) prevents invasion of moisture into inside the hollow chamber (R) from outside the cabinet (4) through the phase inverting mechanism (8).</p>