A sound generating device for a vehicle exhaust system of a motor vehicle includes a housing and a sound generator arranged within the housing. The housing has an upper part, a lower part, and a plug connection for at least one control cable for the sound generator. The plug connection is arranged between the upper part and the lower part. Furthermore, a vehicle exhaust system and a method of manufacturing a sound generating device are disclosed.

A sound generation assembly unit, for an exhaust system of an internal combustion engine, includes a sound generation module (16) with a sound generation module housing to be arranged at an exhaust gas guide element (12) of the exhaust system (14). At least one loudspeaker unit (20) is arranged in the sound generation module housing (18). A rear volume module (30) includes a rear volume module housing (32) and a rear volume (34) formed in the rear volume module housing (32). The rear volume module housing (32) is connected or can be connected to the sound generation module housing (18) for the acoustic coupling of the rear volume (34) to the at least one loudspeaker unit (20).

A method of selecting an operating mode of an active sound generating device of an exhaust system for a motor vehicle includes acquiring information on the operation of the motor vehicle and/or information on the environment of the motor vehicle. On this basis, one of at least two predefined operating modes of the active sound generating device is selected. The selected operating mode or an operating mode to be selected in the future is displayed for the driver. Alternatively or additionally, a characteristic value associated with the selected operating mode or the operating mode to be selected in the future is displayed for the driver. Furthermore, an associated exhaust system and a motor vehicle equipped therewith are described.

An exhaust system for an internal combustion engine of a motor vehicle includes an exhaust-gas line and an associated active silencing device. A sound coupling-in line of the silencing device substantially concentrically surrounds the exhaust-gas line on the outside. A first perforation is provided in an axial portion facing away from a sound line in an area of the exhaust-gas line enclosed by the sound coupling-in line. An axial portion facing the sound line is designed perforation-free at least in a portion. Furthermore, a motor vehicle with such an exhaust system is explained.

In at least one embodiment, a computer-program product embodied in a non-transitory computer readable medium that is programmed to perform selective active noise cancellation (ANC) for a vehicle is provided. The computer-program product comprising instructions to determine an amount of noise present in a first zone and a second zone and to selectively drive only at least one first loudspeaker in the first zone to generate a first cancellation field to cancel road noise and/or engine noise if the amount of noise in the first zone is greater than the amount of noise in the second zone. The computer-program product comprising instructions to selectively drive only at least one second loudspeaker in the second zone to generate the second cancellation field to cancel road noise and/or engine noise if the amount of noise in the second zone is greater than the amount of noise in the first zone.

A loudspeaker arrangement includes an air-tight, rigid, thermo-conductive enclosure (103) with an aperture (115) and an outer surface, and a loudspeaker (101) air-tightly mounted in the aperture (115) to form a locked acoustic volume within the enclosure (103). The arrangement further includes a multiplicity of thermo-conductive fins (112) attached to or integrated in the enclosure (103) at the outer surface thereof. The multiplicity of fins (112) is distributed over the outer surface of the enclosure (103).

A vehicle propulsion system includes an engine arranged to output a first torque to a driveshaft and an electric motor arranged to output a second torque to the driveshaft. The vehicle also includes an automatic transmission arranged to receive an input torque from the driveshaft. The vehicle further includes an exhaust system to output combustion byproduct from the engine. A vehicle controller is programmed to, during deceleration, cause the engine to apply a negative first torque to increase an audible exhaust system sound. The controller is also programmed to activate the electric motor to output a positive second torque such that the input torque to the automatic transmission does not exceed a transmission torque threshold during deceleration.

An exhaust system for an internal combustion engine of a motor vehicle includes a single exhaust-gas inlet line, two exhaust-gas outlet lines connected in an exhaust gas-conducting manner to the exhaust-gas inlet line, and an active silencing device. The active silencing device is connected in a sound-conducting manner to the two exhaust-gas outlet lines. Furthermore, a motor vehicle with such an exhaust system is provided.

A high pressure melamine plant comprising a synthesis section and a melamine purification section, wherein the synthesis section provides a first melamine-containing stream (6), and said melamine purification section comprises: a quencher (2) receiving said first melamine-containing stream (6) from the synthesis section; a stripper (3) fed with a second melamine-containing stream (7) from said quencher (2), wherein purified melamine (11) is collected and vapours (10) are extracted; a heat exchanger (12), wherein said vapours (10) are condensed providing a condensed stream (14); an absorber (4) fed with said condensed stream (14) providing an aqueous solution (15) comprising ammonia and carbon dioxide, at least a portion (15b) of said aqueous solution being exported from the purification section (200) of the plant.

A device includes a housing and a core configured to be secured within the housing. The core includes a microphone configured to detect a sound signal. The core also includes a control board configured to generate a noise-canceling sound signal based on the sound signal and a set of transfer functions. The core further includes a speaker configured to deliver the noise-canceling sound signal. The device also includes a fastener configured to connect the housing to an air filter of an intake vent of an enclosure of a power generation unit.