A panel speaker includes: a panel; a vibration actuator having first and second oppositely-facing surfaces, the first surface facing the panel; a screw that fastens the vibration actuator to the panel, the screw having a head that protrudes beyond the second surface of the vibration actuator; and a back chassis that faces the second surface of the vibration actuator. The back chassis has a protrusion protruding toward the vibration actuator in a portion of the back chassis that faces the head of the screw.

The present invention provides a coaxial speaker, including a frame, a magnetic circuit system, and coaxially arranged first sounding unit and second sounding unit. The magnetic circuit system includes a magnetic bowl and a magnet part. The magnet part includes a first magnet part and a second magnet part, and the first magnet part is arranged with a first channel. The second magnet part is arranged with a second channel. The support component encloses the third channel connected to the through hole of the first diaphragm, and the first channel, the second channel and the third channel are connected to form the sound channel of the second sounding unit. The sound from the second sounding unit is emitted from the through hole of the first diaphragm through the sound channel. The coaxial speaker of the present invention has a good treble effect.

The present invention provides a coaxial speaker, including a frame, a magnetic circuit system, and coaxially arranged first sounding unit and second sounding unit. The magnetic circuit system includes a magnetic bowl and a magnet part. The magnet part includes a first magnet part and a second magnet part, and the first magnet part is arranged with a first channel. The second magnet part is arranged with a second channel. The support component encloses the third channel connected to the through hole of the first diaphragm, and the first channel, the second channel and the third channel are connected to form the sound channel of the second sounding unit. The sound from the second sounding unit is emitted from the through hole of the first diaphragm through the sound channel. The coaxial speaker of the present invention has a good treble effect.

A semiconductor wafer has formed within it a plurality of piston tops of equal area. Each of the piston tops includes a thin flat region from which a majority of the thickness of the original semiconductor wafer may have been removed. A first one of the piston tops has a lower thickness than a second one of the piston tops. The second piston top has at least one hole in it, the volume of the hole corresponding to the difference in thickness between the first and second piston tops, such that the masses of the first and second piston tops differ by less than the variation in thickness between them.

A semiconductor wafer has formed within it a plurality of piston tops of equal area. Each of the piston tops includes a thin flat region from which a majority of the thickness of the original semiconductor wafer may have been removed. A first one of the piston tops has a lower thickness than a second one of the piston tops. The second piston top has at least one hole in it, the volume of the hole corresponding to the difference in thickness between the first and second piston tops, such that the masses of the first and second piston tops differ by less than the variation in thickness between them.

The invention relates to a mobile loudspeaker apparatus for playing back sound. Mobile loudspeaker systems are often disadvantageous in that they have a poor sound quality or require equipment for a good sound quality that is not easy to transport. A loudspeaker apparatus which firstly provides a good sound quality and secondly is also easily transportable is desirable. Previously, these two requirements were often mutually exclusive. By way of a bistable membrane, or a membrane that is stable in more than two states, said membrane being coupleable to the loudspeaker apparatus, it is possible to manage the balancing act between good transportability and a good sound quality of the loudspeaker apparatus. The bistable membrane can be changed from a stable operating state into a stable transport state. By way of a slight pressure at both ends of the bistable membrane, the latter can be rolled up and consequently changed into the transport state. By way of example, in the transport state, the bistable membrane can engage around a cylindrical housing that partly or wholly encloses the loudspeaker apparatus.

The invention relates to a mobile loudspeaker apparatus for playing back sound. Mobile loudspeaker systems are often disadvantageous in that they have a poor sound quality or require equipment for a good sound quality that is not easy to transport. A loudspeaker apparatus which firstly provides a good sound quality and secondly is also easily transportable is desirable. Previously, these two requirements were often mutually exclusive. By way of a bistable membrane, or a membrane that is stable in more than two states, said membrane being coupleable to the loudspeaker apparatus, it is possible to manage the balancing act between good transportability and a good sound quality of the loudspeaker apparatus. The bistable membrane can be changed from a stable operating state into a stable transport state. By way of a slight pressure at both ends of the bistable membrane, the latter can be rolled up and consequently changed into the transport state. By way of example, in the transport state, the bistable membrane can engage around a cylindrical housing that partly or wholly encloses the loudspeaker apparatus.

Disclosed is a sound production device including a housing and a vibration assembly, the vibration assembly comprising a vibration diaphragm and a voice coil combined to one side of the vibration diaphragm; wherein the sound production device further comprises a system stabilization component connected with the voice coil; the system stabilization component is of a line-like structure formed by winding a metal wire, and comprises a first connection part connected to the voice coil, a deformation part, and a second connection part connected to the housing. By adopting the sound production device of this structure, the voice coil will not be polarized under the condition of large displacement, and the system stabilization component having a novel structure does not hinder the free vibration of the voice coil either.

Disclosed is a sound production device including a housing and a vibration assembly, the vibration assembly comprising a vibration diaphragm and a voice coil combined to one side of the vibration diaphragm; wherein the sound production device further comprises a system stabilization component connected with the voice coil; the system stabilization component is of a line-like structure formed by winding a metal wire, and comprises a first connection part connected to the voice coil, a deformation part, and a second connection part connected to the housing. By adopting the sound production device of this structure, the voice coil will not be polarized under the condition of large displacement, and the system stabilization component having a novel structure does not hinder the free vibration of the voice coil either.

An electronic device has an acoustic transducer with an acoustic diaphragm. The diaphragm has opposed first and second major surfaces. A front volume is positioned adjacent the first major surface. A back volume is positioned adjacent the second major surface. An elongated channel defines a barometric vent and extends from a first end fluidly coupled with the front volume to a second end fluidly coupled with the back volume, fluidly coupling the front volume with the back volume. The elongated channel may have a high aspect ratio (L/D), providing the vent with a substantial air mass. The elongated channel may be segmented to define a higher-order filter. For example, a segmented channel can have a cascade of repeating acoustic-mass and acoustic-compliance units, providing the barometric vent with additional degrees-of-freedom for tuning.