The present invention provides a speaker, including: a housing body having an accommodation cavity with a first chamber and a second chamber; a first side wall and a second side wall enclosing the first chamber; a third side wall and a fourth side wall enclosing the second chamber; and a speaker unit including a connection part located in the first chamber and a sounding component connecting to the connection part. A distance between the first side wall and the second side wall is smaller than a distance between the third side wall and the fourth side wall. The speaker enables the connection part to be connected to the side wall of the housing body without the end of the connection part needing to exceed the end of the sounding component, which reduces the volume of the housing body and facilitates the miniaturized design of the speaker.

A system for controlling an electric machine of a vehicle includes, among other things, a controller module configured to attenuate noise from the electric machine by altering a corrective voltage in response to feedback about the noise. The corrective voltage and a fundamental voltage command are supplied to the electric machine as a combined voltage command. The corrective voltage is on a harmonic adjacent to a harmonic of the noise. A method of controlling noise associated with an electric machine of a vehicle includes, among other things, altering a corrective voltage to attenuate noise in response to feedback about the noise. The corrective voltage and a fundamental voltage command are supplied to the electric machine as a combined voltage command. The corrective voltage is on a harmonic adjacent to a harmonic of the noise.

An exhaust pulse balance chamber comprising a circular collar, mid-section that bulges at its center, skirt, and right and left legs, all of which are sealed to the exterior environment and in fluid communication with one another. The outer diameter of the skirt increases in width but not in depth from the proximal end of the skirt to the distal end of the skirt, which is configured to receive the right and left legs. Each leg is bent at a 30-degree angle relative to the central longitudinal axis of the exhaust pulse balance chamber. The invention includes a method of using the exhaust pulse balance chamber to convert a vehicle from a dual-in, single-out exhaust system to a dual-in, dual-out exhaust system.

A soundproofing structure comprises a jacket having an external surface and an opposite internal surface defining an inner compartment. A resilient and deformable soundproofing material is contained within the Inner compartment and engages the internal surface. Constricting elements are mounted to the jacket for constriction of the jacket to provide inner surface pressure against the soundproofing material for compression thereof. The constricting elements are releasable for selectively releasing inner surface pressure against the soundproofing material for expansion thereof against the inner surface. The soundproofing structure defines a size that is selectively modifiable by selective releasing of the contacting elements.

A soundproofing structure comprises a jacket having an external surface and an opposite internal surface defining an inner compartment. A resilient and deformable soundproofing material is contained within the Inner compartment and engages the internal surface. Constricting elements are mounted to the jacket for constriction of the jacket to provide inner surface pressure against the soundproofing material for compression thereof. The constricting elements are releasable for selectively releasing inner surface pressure against the soundproofing material for expansion thereof against the inner surface. The soundproofing structure defines a size that is selectively modifiable by selective releasing of the contacting elements.

A magnetic core housing capable of applying a sufficient force to a magnetic core is provided. A magnetic core housing according to an aspect of the disclosure includes first and second housings each capable of housing a core, a hinge configured to connect the first and second housings with each other so that they can be opened and closed with respect to each other, and a metal spring disposed in the first housing. The metal spring includes a planar part and a pair of spring parts, and also includes reinforcing means for preventing the planar part from being bent due to a force transmitted from the pair of spring parts when the core is housed in the first housing.

A magnetic core housing capable of applying a sufficient force to a magnetic core is provided. A magnetic core housing according to an aspect of the disclosure includes first and second housings each capable of housing a core, a hinge configured to connect the first and second housings with each other so that they can be opened and closed with respect to each other, and a metal spring disposed in the first housing. The metal spring includes a planar part and a pair of spring parts, and also includes reinforcing means for preventing the planar part from being bent due to a force transmitted from the pair of spring parts when the core is housed in the first housing.

A noise suppressing heat exchanger (also referred to as heat sink) includes a plurality of heat dissipating fins formed with baffles. The baffles suppress noise from a fan by slowing air flow and creating internal reflections within the heat exchanger that reflect noise away from the air flow path, absorbing sound energy and potentially setting up standing waves which dissipate noise via destructive interference. Other embodiments may be described and/or claimed.

A muffler for receiving exhaust gas from a combustion engine comprises a shell, first and second inlet pipes each having outlets providing exhaust gas to a mixing chamber within the shell, a first chamber and a second chamber positioned within the shell and a pair of communication pipes each including an inlet receiving exhaust gas from the mixing chamber. Each communication pipe includes an outlet providing exhaust to the second chamber. Each of the communication pipes further includes a Helmholtz opening positioned downstream of the mixing chamber. The Helmholtz openings are open to the first chamber.

A sound attenuating apparatus may include a replaceable sound attenuating device and an electronic receiver configured to mate with the replaceable sound attenuating device. The replaceable sound attenuating device may include a sound attenuating material having an embedded sensor element. The sensor element may have a property that corresponds to a type of replaceable sound attenuating device. The electronic receiver may detect the property of the sensor element. A computing device may determine the type of the replaceable sound attenuating device from the property of the sensor element and perform one or more operations based on the type of replaceable sound attenuating device, including audio control, safety warnings, personal attenuation rating determinations, and the like.