PURPOSE: To improve the resistance to rolling and linearity and to attain ease of assembling by supporting a polygonal shaped voice coil bobbin to a frame with a dampler having plural quadrangular prisms possible for bending and making the number of corners of the polygonal shaped central support section of the damper coincident with that of the said bobbin.

CONSTITUTION: The quadrangular voice coil bobbin 5 is supported to the frame 3 by the damper 8 having plural flexible quadrangular prisms. The damper 8 consists of the quadrangular center support section 10 formed with a quadrangular hole 9 to which the quadrangular voice coil bobbin 5 is inserted and fixed, four flexible quadrangular prisms 12 connected to outer circumference of the center support section 10 via a folding section 11, and an outer support section 14 of quadrangular shape connected to the outer circumference of the quadrangular prism 12 via the folding section 13. Further, the outer support section connected to the outer circumference section of the quadrangular prism via the folding section is provided and the number of vertexes of polygonal shape of the cross section of the coil bobbin and that of the center support section is made coincident with each other.