Abstract: A vibration system includes a vibration plate and an edge portion disposed around the vibration plate. The vibration plate has a first region and a second region that have shapes asymmetrical with each other. The vibration plate is configured such that a weight difference between the first region and the second region is equal to or smaller than a threshold value and besides stiffness at the edge portion is substantially uniform.

Abstract: A vibration system includes a vibration plate and an edge portion disposed around the vibration plate. The vibration plate has a first region and a second region that have shapes asymmetrical with each other. The vibration plate is configured such that a weight difference between the first region and the second region is equal to or smaller than a threshold value and besides stiffness at the edge portion is substantially uniform.

Abstract: Acoustic conversion efficiency is improved and a stable signal reproduction operation is ensured. Provided is a speaker device including: a magnet; a yoke attached to the magnet and at least one sub-plate that is separated from the main plate in an axial direction of the central axis; a coil bobbin formed in a tubular shape and changeable in the axial direction; a voice coil wound around an outer circumferential surface of the coil bobbin, at least a portion of the voice coil being disposed in a main magnetic gap formed between the main plate and the yoke; a vibration plate having an inner circumferential portion connected to the coil bobbin; and a magnetic fluid filling at least one sub-magnetic gap formed between the sub-plate and the yoke, wherein a through-hole positioned in the sub-magnetic gap filled with the magnetic fluid is formed in the coil bobbin.

Abstract: Acoustic conversion efficiency is improved and a stable signal reproduction operation is ensured. Provided is a speaker device including: a magnet; a yoke attached to the magnet and at least one sub-plate that is separated from the main plate in an axial direction of the central axis; a coil bobbin formed in a tubular shape and changeable in the axial direction; a voice coil wound around an outer circumferential surface of the coil bobbin, at least a portion of the voice coil being disposed in a main magnetic gap formed between the main plate and the yoke; a vibration plate having an inner circumferential portion connected to the coil bobbin; and a magnetic fluid filling at least one sub-magnetic gap formed between the sub-plate and the yoke, wherein a through-hole positioned in the sub-magnetic gap filled with the magnetic fluid is formed in the coil bobbin.

Abstract: Acoustic conversion efficiency is improved and a stable signal reproduction operation is ensured. Provided is a speaker device including: a magnet a yoke attached to the magnet and, at least one sub-plate that is separated from the main plate in an axial direction of the central axis; a coil bobbin formed in a tubular shape and changeable in the axial direction; a voice coil wound around an outer circumferential surface of the coil bobbin, at least a portion of the voice coil being disposed in a main magnetic gap formed between the main plate and the yoke; a vibration plate having an inner circumferential portion connected to the coil bobbin; and a magnetic fluid filling at least one sub-magnetic gap formed between the sub-plate and the yoke, wherein a through-hole positioned in the sub-magnetic gap filled with the magnetic fluid is formed in the coil bobbin.