Abstract: A speaker diaphragm includes a protruding dome portion formed at a center portion of the speaker diaphragm, and an annular cone portion extending from an outer peripheral edge of the dome portion in a direction inclined with respect to a protrusion direction of the dome portion. The dome portion and the cone portion are, in a seamless manner, integrally formed of a sheet material made of magnesium or magnesium alloy, and an outer peripheral end of the cone portion at least extends to a substantially identical height position to a maximum protrusion position of the dome portion. An annular step portion for attachment of a cylindrical voice coil bobbin is provided along a boundary portion between the dome portion and the cone portion.

Abstract: A method is provided for manufacturing a speaker diaphragm manufactured using a sheet material made of magnesium or magnesium alloy and including an annular cone portion along an outer peripheral edge of a dome portion. The method includes a dome preformation process of forming a dome preformation portion; a cone preformation process of forming an annular cone preformation portion; and a shaping process of shaping the dome preformation portion into the dome portion by pressing, shaping the cone preformation portion into the cone portion whose outer peripheral end at least extends to a substantially identical height position to a maximum protrusion position of the dome portion, and forming, along a boundary portion between the dome portion and the cone portion, an annular step portion to which a voice coil bobbin is attached.

Abstract: Provided is a speaker diaphragm being able to reduce disturbance of sound pressure frequency properties of a high-tone range including an extremely high-tone range while reducing a manufacturing cost, a speaker including the speaker diaphragm, and the method for manufacturing the speaker diaphragm. A diaphragm 30 includes a dome portion 32 vibratably supported by a speaker body 11 through an edge 14 and protruding in a Z-axis direction, and an annular cone portion 34 extending from an outer peripheral edge of the dome portion 32 in the direction inclined with respect to the Z-axis direction. The dome portion 32 and the cone portion 34 are, in a seamless manner, integrally made of magnesium or magnesium alloy, and an outer peripheral end of the cone portion 34 extends to the substantially same height position as the height P of the maximum protrusion position of the dome portion 32.