Patent ID: 8098876

Claim:
A speaker comprising: a frame; a magnetic circuit that is formed in a radial center of the frame and has a magnetic gap; a voice coil that is inserted in the magnetic gap of the magnetic circuit, the voice coil including a bobbin having a radial cross-sectional area; a damper that is fixed to the frame and the voice coil; and a vibrating plate that is fixed to the frame and the voice coil; wherein an opening is provided in the bobbin of the voice coil; wherein the opening has an area equal to 0.3% or less of a radial cross-sectional area of the bobbin of the voice coil; wherein a joint is formed between a top of a coil part of the voice coil and the bobbin; wherein a clearance gap is formed at the joint between the top of the coil part of the voice coil and the bobbin; and wherein the clearance gap is blocked by a coating material.