PURPOSE: To smooth reproducing characteristics in a wide range from a low voice range to a high voice range by using a dumper with cylindrical double construction consisting of an inside dumper made of synthetic rubber or the like having low viscous resistance and an outside dumper made of synthetic rubber or the like having high viscous resistance.

CONSTITUTION: The dumper 5 has coaxial double construction consisting of the cylindrical inside dumper 5A made of synthetic rubber or the like having comparatively low viscous resistance and the cylindrical outside dumper 5B made of synthetic rubber or the like having comparatively high viscous resistance. The thickness of the inside dumper 5A is formed larger than that of the outside dumper 5B. Therefore, a prescribed compression stress is previously applied to the inside dumper 5A after the completion of assembling. The brake of the inside dumper 5A is applied to a high voice frequency band having a comparatively small deflection and the brake of the outside dumper 5B is applied to a low voice frequency band having a comparatively large deflection, so that smooth reproducing characteristics can be obtained in the wide range from the low frequency range to the high frequency range.