A speaker comprises: a magnetic circuit composed of a pot yoke, a magnet, and a pole piece; a diaphragm shaped conical, defining an outer periphery and an inner periphery, and having a surround half-rolled and fixedly disposed at the outer periphery and a voice coil bobbin with a voice coil wound thereon fixedly disposed at the inner periphery; a spider having an outer diameter equal to or larger than the outer diameter of the surround; a frame having the magnetic circuit fixedly disposed at its central opening; and a spacer ring fixedly disposed inside the frame, and having a surround edge receiving portion adapted to fixedly receive the entire outer edge of the surround thereon.