A loudspeaker diaphragm (12) comprising a woven fibre body supports damping material (25), for example PVA polymer, on a rearward-facing surface (24). The woven fibre body may be formed of lengths (14) non-metallic fibre material (for example glass fibre) coating with a thin metal coating (32). The mass of the layer of damping material (25) may be less than the mass of the woven fibre body. An attractive sparkly looking loudspeaker diaphragm (12) may thus be provided which damps undesirable vibration whilst providing a flatter frequency-response curve (50).

A sound producing package structure configured to produce sound includes a substrate, a sound producing component and a conductive adhesive layer. The sound producing component is disposed on the substrate, and the sound producing component is configured to generate an acoustic wave corresponding to an input audio signal. The conductive adhesive layer is disposed between the substrate and the sound producing component by a surface mount technology.

A MEMS device and a method of manufacturing the same are provided. A semiconductor device includes a substrate and a membrane over the substrate. The membrane includes a piezoelectric material configured to generate charges in response to an acoustic wave. The membrane includes a via pattern having first lines that partition the membrane into slices such that the slices are separated from each other at a first region near an edge of the membrane and connected to each other at a second region.

Water impermeable, air permeable membrane assemblies are described herein. In some embodiments, the assemblies include a polymer membrane and at least one support structure. Certain assemblies are configured to provide an acoustic impedance having phase angle of +45 degrees to −45 over a frequency range of 50 to 20,000 Hz.

Provided is an acoustic diaphragm with required properties for a vibrating part and an edge part thereof. The acoustic diaphragm comprises a vibrating part 11 and an edge part 12 located at an outer periphery of the vibrating part, wherein the vibrating part comprises a thermoplastic liquid crystal polymer (TLCP) having a certain composition; the edge part comprises a TLCP having a same composition as the TLCP of the vibrating part; and the vibrating part 11 and the edge part 12 have elastic moduli E.sub.d and E.sub.e measured by nanoindentation technique, respectively, which satisfy the following formula: E.sub.d>E.sub.e. For example, a ratio E.sub.d/E.sub.e of the elastic modulus E.sub.d of the vibrating part 11 to the elastic modulus E.sub.e of the edge part 12 may fall within a range of from 1.05 to 5.0.

A soundboard panel assembly for a vehicle, including a mounting structure, a soundboard panel connected to the mounting structure, and an inertial-type acoustic transducer connected to the soundboard panel.

Provided are a polymer-based piezoelectric composite material and a piezoelectric film which have high productivity and are capable of suppressing degradation of piezoelectric conversion efficiency in an environment where the temperature and the humidity are severe. The polymer-based piezoelectric composite material is a polymer-based piezoelectric composite material including piezoelectric particles in a matrix containing a polymer material, in which the polymer-based piezoelectric composite material contains greater than 500 ppm and 10000 ppm or less of a substance on a mass basis which has an SP value of less than 12.5 (cal/cm.sup.3).sup.1/2 and is in a liquid state at room temperature, voids are formed in the polymer-based piezoelectric composite material, and an area ratio of the voids in a cross section of the polymer-based piezoelectric composite material is 0.1% or greater and 20% or less.

Provided is a piezoelectric film capable of realizing an electroacoustic conversion film with an excellent heat dissipation property, in which a sufficient sound pressure with respect to an input operating voltage is obtained. The piezoelectric film is a piezoelectric film including a polymer-based piezoelectric composite material which contains piezoelectric particles in a matrix containing a polymer material, electrode layers which are laminated on both surfaces of the polymer-based piezoelectric composite material, and a protective layer laminated on a surface of at least one electrode layer, in which in a case where a cross section of the piezoelectric film is observed with a scanning electron microscope, at least one electrode layer has a plurality of projections directed toward the protective layer, and the number of projections is in a range of 2 to 40 per visual field of 85 μm in the cross section.

A metamaterial loudspeaker diaphragm is disclosed. The diaphragm includes a cone structure having a periodic arrangement of two dissimilar materials, e.g., soft and hard, in an alternating periodic pattern to achieve an anisotropic structure, which results in passive amplification of the sound. The anisotropic cone structure includes a baseline cone material and a different, compatible second material. The cone includes a body having a conical cross-section, an interior side, an exterior side, and concentric circles of material alternating between a soft material and a rigid material. Circumferential grooves disposed within the concentric circles include rigid material. Concentric circles including rigid material line the interior side of the body. Substantially all the soft material of the concentric circles is disposed on the exterior side of the cone. Spokes disposed on the exterior side of the cone extend from a base toward a vertex of the cone.

A vibration component includes a dome, a diaphragm, and a voice coil. The dome includes a porous heat dissipation layer, the diaphragm partially covers a portion of a surface of the dome, and the voice coil is connected with a side of the dome facing away from the diaphragm.