Loudspeaker enclosures are disclosed that support improved acoustic radiation efficiency at low audible frequencies without compromising acoustic radiation efficiency at mid and high audible frequencies. Embodiments include enclosures having a primary chamber and a secondary chamber acoustically coupled to the primary chamber via a passive radiator. The geometrical characteristics of the secondary chamber and the corresponding air plenum are tailored for enhanced efficiency at low frequencies.

The present disclosure discloses an assistive listening device. The assistive listening device includes a signal input module configured to receive an initial sound and convert the initial sound into an electric signal, a signal processing module configured to process the electric signal and generate a control signal, and at least one output energy converter configured to convert the control signal into a bone conduction sound wave that can be perceived by a user and an air conduction sound wave that can be heard by the user's ears. Within a target frequency range, the air conduction sound wave is transmitted to the user's ears, so that a sound intensity of the air conduction sound heard by the user's ears is greater than a sound intensity of the initial sound received by the signal input module.

An acoustic transducer (30), comprising: a support structure (36); an active assembly comprising a base plate (32) supported by the support structure (36) and a piezoelectric body (34) supported by the base plate (32); and a passive vibrator (38) supported by the support structure (36) and coupled via the support structure (36) to the active assembly (32, 34) so that vibration of the active assembly (32, 34) drives the passive vibrator (38). The active assembly (32, 34) and the passive vibrator (38) have the same resonant frequency.

An MEMS device includes a substrate with a substrate plane, a mass element having a rest position and configured to perform a deflection from the rest position parallel to the substrate plane and in a fluid surrounding the mass element. Further, the MEMS device includes a spring arrangement that is coupled between the substrate and the mass element and configured to deform based on the deflection. An actuator structure is provided that is coupled to the mass element by means of a coupling and configured to apply a force to the mass element by means of the coupling to cause the deflection and a movement of the fluid.

A loudspeaker comprises a first diaphragm, a second passive diaphragm, and a drive unit coupled to the first diaphragm. The drive unit is configured to drive the first diaphragm in a direction of excursion upon applying electrical energy to the drive unit. The second passive diaphragm is arranged opposing the first diaphragm. The second passive diaphragm is mainly driven by sound waves emitted from the first diaphragm.

A speaker device of the present disclosure includes a speaker unit, a first passive radiator disposed adjacent to a vibrating plate of the speaker unit, a second passive radiator located in a first direction with respect to the first passive radiator and disposed to be opposed to the first passive radiator, a first cabinet including a first wall section and forming a sealed acoustic space, and a second cabinet including a second wall section, including an opening section adjacent to the first passive radiator, and forming an opened acoustic space. The second passive radiator is located in a second direction with respect to a first imaginary surface passing the first wall section of the first cabinet. The second wall section of the second cabinet does not project in the first direction with respect to the first wall section.

A passive radiator unit and a speaker system using the passive radiator unit are provided. The passive radiator unit includes a first passive radiator comprising a first moving mass; a second passive radiator oriented opposite to the first passive radiator, the second passive radiator comprising a second moving mass; and a connecting structure connected between the first moving mass of the first passive radiator and the second moving mass of the second passive radiator. The connecting structure is configured to have a greater radial stiffness than an axial stiffness thereof to thereby prevent rocking movements while allowing normal vibrations of the first passive radiator and the second passive radiator in an axial direction of the passive radiator unit.

The invention provides a sounding device. The sounding device comprises a housing body with an accommodating space, a one-way inlet valve and a one-way outlet valve. A speaker unit partitions the accommodating space into a front cavity and a back cavity. The one-way inlet valve communicates the outside and the back cavity and is used for introducing air into the back cavity. The one-way outlet valve communicates the back cavity and the outside and is used for discharging the air in the back cavity outside. A first through hole communicating the outside and the back cavity is formed in the housing body. The invention also provides a mobile terminal. Compared with the related art, the sounding device and the mobile terminal of the invention have better reliability and better performance.

The present application relates to the technical field of composite film, and more particularly, to a diaphragm composite material and a preparation method thereof. The diaphragm composite material includes a polyethylene naphthalate (PEN) film layer, an aluminum-plated film layer, an aerogel layer, and an elastic adhesive layer disposed between the PEN film layer and the aluminum-plated film layer for bonding the PEN film layer and the aluminum-plated film layer, the aerogel layer is coated on one side of the aluminum-plated film layer away from the elastic adhesive layer. The diaphragm composite layer of the present application has high strength and strong rigidity, has better vibration dampening and noise-reducing effects, and wear-resistant and corrosion-resistant effects, and is worthy of popularization.

Disclosed in the present invention are a sound generation device and a portable terminal. The sound generation device comprises a vibration system and a magnetic circuit system, the vibration system and the magnetic circuit system being mounted and fixed to an housing. The housing comprises a first shell and a second shell that are connected and fixed together, the vibration system comprises a first diaphragm and the magnetic circuit system comprises a magnetic yoke, and wherein the first diaphragm is mounted on one surface of the first shell far away from the second shell, and the magnetic yoke and the second shell are injection molded as an integrated part. In the sound generation device of the present invention a conventional plastic housing is split into two shells, by fixing the magnetic yoke to the second shell by injection molding so that the magnetic yoke and the second shell become an independent part which is integrally arranged, it can reduce the assembling process of the Magnetic yoke and the housing, improve the assembling efficiency and connecting strength of the sound generation device, and can provide a bigger space for the magnetic circuit system and improve the product performance.