Loudspeaker diaphragm and loudspeaker including same

A loudspeaker diaphragm comprising:

• a cone including:
• a first outer periphery;
• an outer peripheral part along the first outer periphery;
• a first inner periphery having a circular shape;
• and
• an annular first section along the outer peripheral part, and the annular first section is thinner than a remaining portion of the cone other than the annular first section, and
• an annular edge including:
• a second outer periphery;
• a second inner periphery;
• and
• an inner peripheral part along the second inner periphery,
• wherein the cone has a surface curved from the first outer periphery to the first inner periphery,
• the first outer periphery is defined, when seen from a central axis of the first inner periphery, by smooth connection of three larger-diameter parts tangent to a first circle having a first radius, and three smaller-diameter parts each located between adjacent two of the three larger-diameter parts and tangent to a second circle having a second radius smaller than the first radius,
• in the cone, a shape defined by connecting together points at a same position on the central axis of the first inner periphery is more circular as the points approach the first inner periphery from the first outer periphery,
• the cone has a first side and a second side as a reverse side of the first side, the first inner periphery projects from the first outer periphery in the second side,
• a radius of the second inner periphery is smaller than the second radius, and
• the inner peripheral part of the annular edge is bonded to the first side of the cone at the outer peripheral part of the cone.