133 results about "Resonance chamber" patented technology

Various embodiments of an ear-wearable electronic device are disclosed. The device includes a housing having a top shell and a bottom shell, a microphone disposed within the housing, and an acoustic path disposed at least partially within the housing and extending between an acoustic port disposed at an outer surface of the housing and an outlet disposed within the housing that acoustically couples the acoustic path to an inlet of the microphone. The device further includes an acoustic filter disposed at least partially within an inner surface of the top shell and includes a neck and a resonance cavity acoustically coupled to the neck. The acoustic filter is acoustically coupled to the acoustic path via the neck. Further, the acoustic filter is configured to reduce an intensity of acoustic waves sensed by the microphone in a first frequency range.

The air-pulse generating device comprises a film structure, operating at an ultrasonic operating frequency, and a resonant chamber, formed on a side of the film structure. A resonance is formed within the resonance chamber. Due to the resonant chamber, the APG device has a peak on a frequency response of an acoustic property of the APG device at the ultrasonic operating frequency.

The invention discloses a frequency mixing sound demodulator based on a curled structure and a use method thereof in the acoustics field, the demodulator is used for separating frequency mixing sound mixed by a plurality of sound waves with preset frequencies according to respective frequencies, and the demodulator comprises an air waveguide for transmitting the sound waves, and blocking structures arranged on two sides of the air waveguide for blocking the sound waves from penetrating, and a plurality of curled structures that capture corresponding preset frequency sound waves; curled structures are arranged in the barrier structure on at least one side of the air waveguide at intervals, one end of each curled structure is open, and the other side is closed; a plurality of cross beams for blocking penetration of sound waves are arranged in each curled structure, and an internal channel of each curled structure is divided into different lengths to serve as different acoustic resonant cavities so as to capture the sound waves with different frequencies; the closed end of each curled structure is a detection end of each preset frequency sound wave. The invention solves the problem that the existing method is difficult to instantly separate the frequency mixing sound signal and carry out information transmission.

The embodiment of the invention provides a compressor sound insulation structure and a control method thereof. The compressor sound insulation structure comprises a sound insulation cover and a deformation device. The compressor is covered with the sound insulation cover. The sound insulation cover comprises an inner sound insulation layer and an outer sound insulation layer which are sequentially arranged from inside to outside, and a resonant cavity is formed between the inner sound insulation layer and the outer sound insulation layer; the inner sound insulation layer is provided with a plurality of through holes and is made of a shape memory material; the deformation device is arranged in the soundproof cover and used for receiving the operation frequency of the compressor and driving the inner soundproof layer to deform according to the operation frequency so that the hole diameter of the through hole can be changed. Through the arrangement of the resonant cavity, the intensity of low-frequency noise is gradually weakened under the resonance effect, and therefore effective absorption of the low-frequency noise is achieved; by arranging the deformation device and the inner sound insulation layer made of the shape memory material, intelligent adjustment of the hole diameter of the through hole is achieved, so that the sound absorption frequency of the inner sound insulation layer and the resonant cavity is dynamically adjusted, the noise reduction requirement for broadband noise is met, and the operation noise of the outdoor unit is reduced.

The present invention discloses a rail transit sound barrier based on phononic crystal cells, which is divided into several cells of equal volume by dividing modules; a resonance cavity with an opening on one side is embedded in each cell; one side of the opening of the resonance cavity faces the sound source; the opening extends outward in a trumpet shape to increase the sound receiving area; several phononic crystal cells that do not contact each other are fixedly arranged in the resonance cavity; the resonance cavity in the present invention can achieve triple acoustic performance improvements, namely sound insulation, sound elimination and sound absorption: its overall appearance belongs to a Holmhelix resonance cavity, which is itself a good sound elimination device, which is the first sound elimination; the trumpet-like opening structure on the sound source side is conducive to the introduction of sound waves, and the phononic crystal cells are arranged inside, which is the second sound insulation of the device; the tail adopts a boss with the same size as the end of the trumpet mouth, which is conducive to the flow of sound waves, and a certain thickness of sound-absorbing rock wool is used on the inner wall of the tail, which is the third sound absorption.

The invention discloses a strong premixing combustion chamber for restraining combustion noise based on a Helmholtz resonant cavity, and relates to the technical field of energy and power. Air and fuel enter the mixing cavity through corresponding connectors to be strongly premixed, premixed gas enters the hearth to be combusted through slit channels among water cooling channel branch pipes, a water cooling channel array can prevent backfire, the Helmholtz resonant cavity is connected with the hearth through a cavity neck and is provided with an air film cooling channel, the size of the Helmholtz resonant cavity needs to measure combustion noise, and a frequency spectrum is analyzed to obtain characteristic frequency. The neck length, the cross section area and the resonant cavity volume are calculated according to a Helmholtz resonance formula, and the sound absorption effect is verified in combination with a low-order thermoacoustic model. Combustion efficiency is improved through the strong premixing and slit water cooling design, tempering is prevented, NOx is reduced, the diffusion combustion problem is solved, the targeted design resonant cavity is matched with air film cooling, the defects that an existing silencing structure is large in size, poor in adaptation and low in high-temperature reliability are overcome, complex active control is not needed, cost is low, applicability is high, and the application range is wide. And cooperative control of high efficiency, low emission and unstable combustion is realized.

The invention discloses an impedance combined type noise elimination structure parameter design method, which comprises the following steps of: firstly, determining target noise reduction quantity and target sound absorption center frequency of a resistive noise elimination section and a resonant cavity resistance noise elimination section according to noise source characteristics, and then iteratively adjusting structural parameters of the resistive noise elimination section and parameters of the resonant cavity resistance noise elimination section; and until the deviation between the sound absorption center frequency of the resonant cavity and the target sound absorption center frequency is within an allowable range, and the noise reduction amounts of the resistive noise elimination section and the resonant cavity resistant noise elimination section respectively reach the corresponding target noise reduction amounts. According to the method, parameters of the impedance combined type silencing structure can be effectively, rapidly and reasonably determined, and the problem that an existing impedance combined type silencer lacks a systematic method for coordinating multi-target constraints such as silencing performance, airflow resistance and structural strength is effectively solved.

The application discloses a microwave magnetic nozzle thruster without an exciting antenna, belongs to the field of space electric propulsion, and aims at solving the problems of antenna ablation and performance drift of a conventional microwave magnetic nozzle thruster. The microwave magnetic nozzle thruster comprises a discharge chamber and a resonance chamber which are coaxially arranged, a gas inlet pipe is arranged through the center of the thruster in an axial direction, the resonance chamber is coaxially arranged outside the gas inlet pipe, the gas inlet pipe is in communication with the discharge chamber in a gas path, and the gas inlet pipe is isolated from the resonance chamber in a gas path; microwaves are fed into the resonance chamber, repeatedly reflected through a short-circuit end and an open-circuit end of the resonance chamber to generate a standing wave, so that a strong standing wave electric field is formed at the open-circuit end; the strong standing wave electric field ionizes working gas in the discharge chamber to form plasma; the plasma is axially accelerated under a characteristic magnetic field of a divergent magnetic nozzle which is externally applied, forms a plume jet and is ejected out of the thruster, so that a thrust is formed.

The present invention discloses a muffler, which comprises: a waveguide provided with a sound wave inlet; a first resonance cavity and a second resonance cavity arranged along the tube length direction of the waveguide, the first resonance cavity being arranged closer to the sound wave inlet of the waveguide than the second resonance cavity, and the first resonance cavity and the second resonance cavity being Helmholtz resonance cavities; a first neck tube communicating with the waveguide is provided on the first resonance cavity, a second neck tube communicating with the waveguide is provided on the second resonance cavity, and the cross-sectional area of the second neck tube is larger than that of the first neck tube. By arranging two Helmholtz resonance cavities with different cross-sectional areas of the neck tubes on the waveguide, the present invention has a relatively high prediction accuracy of the noise reduction effect. Secondly, the first neck tube and the second neck tube adopt a bent tube design, which can not only ensure a more compact structure, but also is beneficial to low-frequency noise reduction and miniaturization design.

The present invention is a washboard instrument with a resonance chamber that improves the overall sound quality produced by the instrument. The resonance chamber improves the amplitude of any sound produced at a considerably lower rate of loss. Further, the instrument was designed to produce a wide variety of different sounds due to the number of different surfaces that can be struck. Additionally, the front panel can accommodate a number of different accessories that include, but not limited to, bells, jam blocks, and cymbals.

Motor vehicle (1, 12, 17) with an interior floor (3) defining a passenger compartment (2) of the motor vehicle (1, 12, 17) on the floor side, at least one electrical energy storage device (4) arranged at least partially on the floor side below at least one section of the interior floor (3), and at least one low-frequency loudspeaker (8, 15, 21) arranged at least partially in the passenger compartment (2), wherein at least one cavity (11) is provided between the interior floor (3) and the electrical energy storage device (4), characterized in that the low-frequency loudspeaker (8, 15, 21) is arranged on at least one opening (18) of the interior floor (3) communicating with the cavity (11) such that the cavity (11) forms a resonance chamber for the low-frequency loudspeaker (8, 15, 21), wherein the opening (18) is on a dome-shaped projection pointing towards the passenger compartment (2). (13, 19) of the interior floor (3) is arranged.

The application discloses a structure and method for inhibiting thermal acoustic oscillation of a gas turbine combustor, relates to the field of inhibiting thermal acoustic oscillation of a gas turbine combustor, and is applied to a combustor and comprises an outer layer pipe and an inner layer pipe, wherein the inner layer pipe is located in the outer layer pipe and the inner layer pipe and the outer layer pipe are coaxial; a back cavity is formed between the inner layer pipe and the outer layer pipe; a plurality of acoustic holes are arranged on the inner layer pipe and the acoustic holes are communicated with the back cavity; the space corresponding to the acoustic holes in the back cavity is a resonance cavity; and each acoustic hole and the resonance cavity form a resonance system. The application can effectively inhibit thermal acoustic oscillation of the gas turbine combustor and reduce the influence caused by the thermal acoustic oscillation.

The utility model relates to an airflow generating device and a breathing machine, the breathing machine comprises the airflow generating device, the airflow generating device comprises a shell and a fan, the shell is internally provided with an inlet cavity, a fan cavity and an outlet cavity which are sequentially communicated in the airflow flowing direction, and the fan is arranged in the fan cavity; the shell is further internally provided with a resonant cavity, the resonant cavity is adjacent to the outlet cavity and the fan cavity and is isolated from the fan cavity, and the cavity wall of the resonant cavity is provided with a plurality of noise reduction holes communicating with the outlet cavity. Noise generated by the fan and noise generated by disordered airflow in the outlet cavity can be transmitted into the resonant cavity through the noise reduction holes, and then the noise is continuously rebounded by the cavity wall of the resonant cavity in the resonant cavity and then is gradually consumed, so that a good noise reduction effect can be achieved without installing noise reduction cotton or sound insulation cotton, the cost can be saved, and the noise reduction efficiency is improved. The assembly process is simplified, fine particles are not generated to harm the body health of a user, and then the use experience of the breathing machine is improved.

This application provides a speaker device and an acoustic structure with a waveguide structure as the rear cavity of a single unit. The acoustic structure with a waveguide structure as the rear cavity of a single unit includes a main speaker enclosure, a waveguide structure, and a dual-sided speaker module. The waveguide structure is disposed within the housing space of the main speaker enclosure and includes a waveguide cavity and a resonant rear cavity connected to the waveguide cavity. The dual-sided speaker module includes a front speaker diaphragm and a rear speaker diaphragm disposed opposite to the front speaker diaphragm. When the second opening is open, the front speaker diaphragm operates to generate a first sound wave, which is guided by the waveguide cavity through the second opening to produce sound, and the resonant chamber of the resonant rear cavity becomes the resonant rear cavity for the operation of the front speaker diaphragm. When the second opening is closed, the rear speaker diaphragm operates to generate a second sound wave, which is guided by the sound channel through the first opening to produce sound, and the resonant chamber of the resonant rear cavity becomes the resonant rear cavity for the operation of the rear speaker diaphragm.

The invention discloses a manufacturing method of a gas outlet pipe assembly of an automobile exhaust emission silencer, and relates to the field of automobile exhaust treatment. The manufacturing method of the air outlet pipe assembly of the automobile exhaust emission silencer comprises the five steps of material pretreatment, internal high-pressure forming, punch forming, assembly assembling and intelligent integration. According to the invention, through the combination of the double-circulation noise reduction design and the variable volume resonant cavity, the noise reduction performance is obviously improved; specifically, broadband noise reduction is achieved, specifically, high-frequency noise is effectively reduced through the double structure of the circulating pipe and the spring-shaped pipe, and the low-frequency noise treatment effect of the resonant cavity is further optimized by adjusting the shape of a cavity body and distribution of partition plates; vibration suppression: multiple layers of sound insulation cotton are embedded into the inner wall of the air outlet pipe, and an elastic connecting sleeve is combined, so that vibration transmission is effectively reduced, and the silencing effect is further improved; the design is not only suitable for traditional fuel vehicles, but also suitable for new energy hybrid vehicles, and diversified market requirements are met.

The invention discloses a resonance chamber vibration quantity increasing device. The resonance chamber vibration quantity increasing device comprises a fixing mechanism fixedly connected with a resonance chamber body and a string supporting cross beam fixed to the fixing mechanism. And the string supporting cross beam is arranged above the resonator panel between the lower bridge of the resonator and the bottom of the resonator body. The resonance box has the advantages that the independent string supporting device is arranged, the force of strings applied to the resonance box panel through the lower bridge of the resonance box is shared, the resonance box panel can be made to be very thin, the vibration amplitude of the resonance box panel is improved, the vibration volume of the resonance box is greatly improved, the volume of the resonance box type musical instrument is greatly improved, and the resonance box type musical instrument is more attractive in appearance. The tone expressive force is greatly improved, the sound is more transparent and loud, the high pitch is more penetrable, and the low pitch is more vigorous. As the string supporting device shares the pressure of most strings, the pressure of the panel is released, and the service life of the resonator is greatly prolonged.

The application discloses a high-pressure shell assembly for an electric compressor, an electric compressor, an air conditioning system and a vehicle, and relates to the technical field of electric compressors. The high-pressure shell assembly comprises a high-pressure shell, a high-pressure cavity and a refrigerant discharge port are formed on the high-pressure shell, a compression component of the electric compressor is adapted to discharge compressed refrigerant to the high-pressure cavity, and the refrigerant discharge port is used for discharging refrigerant outside the high-pressure shell; a resonance cavity and an oil separation cavity which are in communication with each other are further formed on the high-pressure shell, the oil separation cavity is in communication with the high-pressure cavity to receive refrigerant flowing out of the high-pressure cavity, a sound attenuation nozzle is arranged in the resonance cavity, a flow-through channel is defined between the sound attenuation nozzle and the inner wall surface of the resonance cavity, one end of the cavity in the sound attenuation nozzle is in communication with the refrigerant discharge port, and the sound attenuation nozzle is provided with a sound attenuation hole which is in communication with the cavity and the flow-through channel. The high-pressure shell assembly for the electric compressor can eliminate noise and pressure pulsation accompanied by gaseous refrigerant, and has good sound attenuation effect.

The present invention generally concerns an adjustable pneumatic device that creates sound. More specifically, the present invention improves diaphragm-based air horns by having a unique base with an extended pressure chamber, an adjustable volume lever, a tunable shaft that generates specific tonal pitches, and an optional sound amplification plate. The horn includes: an inverted closet flange, an annulus pressure plate, a pressure relief tube, a bushing connector, a collar coupling, an air inlet system, a flexible diaphragm, a resonator, rivets, screws, an optional sound amplification plate, and an air pump. Within the pressure chamber, a tube presses against a diaphragm via tension, causing the diaphragm to stretch beyond the lower portions of the base's bottom most surface. Compressed air traverses chamber spaces around the tube and about the extended pressure chamber to trigger diaphragm vibrations that generate sound at the resonator from 109 decibels to 129 decibels.

The utility model discloses an electronic expansion valve and refrigeration plant relates to electronic expansion valve technical field, this electronic expansion valve includes valve body, transmission subassembly, valve needle and mounting seat, and valve body has the valve mouth, transmission subassembly includes nut and screw rod, and nut is sealedly connected with valve body, and screw rod is cooperated with the nut thread, valve needle is connected with screw rod, and can be axially removed to open or close the valve mouth, and the circumferential side of mounting seat is sealedly connected with the inner wall of valve body, and the resonance cavity is defined between mounting seat and nut, and the valve cavity that communicates valve mouth is defined with valve body and mounting seat, and mounting seat has the guide channel that is arranged coaxially with nut, and valve needle is worn guide channel and is matched with the clearance of guide channel, wherein, mounting seat still is equipped with the sound -absorbing passage that communicates resonance cavity and valve cavity. The utility model provides technical scheme to utilize mounting seat and divide resonance cavity and valve cavity, and construct the sound -absorbing ware structure through resonance cavity and sound -absorbing passage to reduce the noise that high pressure refrigerant produces in the flow process in valve cavity because of the flow rate mutation.

The invention belongs to the technical field of aviation noise control and low-frequency sound absorption and noise reduction, and particularly relates to a single-layer spiral cavity labyrinth metasurface structure which comprises a front cover plate, a coplanar spiral folding cavity plate and a rear cover plate. The front cover plate, the coplanar spiral folding cavity plate and the rear cover plate are all of cylindrical structures, and the coplanar spiral folding cavity plate is connected between the front cover plate and the rear cover plate; under the action of sound waves, the air column in the hole neck of the center hole of the front cover plate vibrates back and forth like a piston, and in the vibration process, due to the damping effect of the neck wall on the air column, sound energy is converted into heat energy to be dissipated. When sound waves generate local resonance in the spiral cavity of the sound absorption plate, if the frequency of incident waves is equal to the inherent frequency of the resonant cavity, a resonance phenomenon can be generated, at the moment, the vibration amplitude of the air column is maximum, the sound pressure in the spiral cavity is obviously increased, the corresponding sound energy consumption is maximum, and a sound absorption peak is formed, so that the purpose of eliminating noise is achieved.

The application provides a silencer and a compressor comprising the same, relates to the technical field of compressors, and solves the technical problem of poor silencing effect of the silencer. The silencer comprises a silencing body arranged on a flange, the silencing body has a resonance cavity, the resonance cavity is communicated with an exhaust port of the flange; the resonance cavity is formed by at least two unit cavities in series, all the unit cavities comprise at least two unit cavities with different heights and / or widths; the compressor comprises the flange and the silencer arranged on the flange. The application forms a plurality of resonance cavities with different volumes by arranging the resonance cavity into a plurality of unit cavities with different heights and / or widths. When the airflow enters the resonance cavity, the resonance cavity will vibrate, so that the airflow consumes sound energy by overcoming frictional resistance. Since the resonance cavities with different widths and / or heights are arranged in series, the resistance of the airflow is further increased, the aerodynamic noise of the high-pressure refrigerant is reduced, and the silencing effect of the silencer is improved.

The utility model discloses a ventilation sound insulation board which comprises a main body, the main body is of a square hollow structure defined by a first layer board, a second layer board and a side board, an air inlet hole is formed in the first layer board, and an air outlet hole opposite to the air inlet hole is formed in the second layer board; the low-frequency noise elimination assembly comprises an air inlet pipe and an air outlet pipe, one end of the air inlet pipe is perpendicular to the first layer plate and fixed to the air inlet hole, and the other end of the air inlet pipe is located in the main body; one end of the air outlet pipe is perpendicular to the second layer plate and fixed to the air outlet hole, the other end of the air outlet pipe is located in the main body, the pipe diameter of the other end of the air outlet pipe is larger than that of the air inlet pipe, the air outlet pipe is sleeved on the outer surface of the other end of the air inlet pipe, and a resonant cavity is formed between the air outlet pipe and the air inlet pipe for low-frequency noise elimination. According to the ventilation sound insulation board, the ventilation effect can be improved while the sound insulation effect is guaranteed, the structure is simple, and the low-frequency effect can be improved.

The utility model discloses an aluminium alloy window of sound insulation and noise reduction, and its technical key points are: including window frame and window sash, the sound insulation glass is fixedly connected in the window sash, the inside of window frame is provided with the resonance cavity, is provided with the partition strip on the inside wall of both sides of resonance cavity and will be divided into a plurality of partition space, the relative angle of every partition strip is randomly set and is connected two partition space between intercommunication, is provided with the recess on the side of window frame, the side of window sash is provided with the convex edge for with recess cooperation, is provided with the fixed mechanism on the convex edge. Advantage is through setting resonance cavity, when the sound enters resonance cavity, the partition strip of random angle will make the times of sound wave wall rebound increase, thereby makes the sound energy of noise in the rebound process is gradually wasted and weak, for the gap of door and window, then is formed by the soft hair pad fluff, the gap also forms the cavity structure, and the fluff is vibrated from itself, thereby further absorbs the sound energy, to this to realize the effect of sound insulation and noise reduction.

The application provides a double-cavity communication type loudspeaker sound amplification cavity, which comprises two-stage resonance cavities connected in series, an incident neck, a communication neck component and an electromagnetic sound-electricity transducer. The two-stage resonance cavities comprise a first-stage resonance cavity and a second-stage resonance cavity. One end of the first-stage resonance cavity with a small inner diameter is connected with the incident neck, and the other end of the first-stage resonance cavity with a large inner diameter is connected with one end of the communication neck component. One end of the second-stage resonance cavity with a small inner diameter is connected with the other end of the communication neck component. The large inner diameter of the first-stage resonance cavity, the inner diameter of the communication neck component and the small inner diameter of the second-stage resonance cavity are equal. The diaphragm in the electromagnetic sound-electricity transducer is fixedly and sealingly connected with the output end surface of the second-stage resonance cavity.

The invention belongs to the technical field of silencing and noise reduction, and discloses a silencing unit, a silencing unit construction method and a silencing structure. Each silencing unit comprises an acoustic impedance coupling structure and a plurality of resonant cavity structures which are connected in parallel and sequentially arranged in the X direction and / or the Y direction, the interiors of the resonant cavity structures are hollow to form inner cavities, different resonant cavity structures are provided with through hole panels with different porosities in the Z direction, and sound waves can enter the inner cavities through silencing holes formed in the through hole panels. An acoustic impedance coupling channel is formed in the acoustic impedance coupling structure, the acoustic impedance coupling structure is arranged in the resonant cavity structure, and inner cavities of the two resonant cavity structures located at the two ends are connected in a penetrating mode in the X direction; and at least one resonant cavity structure between the resonant cavity structures at the two ends is not communicated with the acoustic impedance coupling channel. Based on an existing manufacturing process, the silencing unit can effectively regulate and control the height in the axis direction, the low-frequency noise reduction effect is enhanced, and the range of the silencing frequency band is widened.

A speaker module is disclosed. The speaker module includes a shell, a speaker unit and a ring body. The speaker unit includes a frame, a magnetic circuit system, a vibration system having a diaphragm in a ring shape surrounding the ring body. The magnetic circuit system includes a yoke and a main magnetic unit. A through hole penetrates through the yoke and the main magnetic unit and is covered by a waterproof and air-permeable membrane. The ring body is sandwiched between the main magnetic unit and the shell. The diaphragm is fixed between the frame and the main magnetic unit. The membrane, the main magnetic unit, the ring body and the shell together form a resonance cavity. An access of the ring body communicates the resonance cavity and a front cavity. The speaker module enhances the high-frequency sensitivity, and also saves the space and simplifies the production process.

The embodiment of the utility model discloses a sound wave rhythm device, which relates to the technical field of physiotherapy equipment and comprises a vibration box, a resonator, a circuit board, a battery and a loudspeaker. The circuit board is electrically connected with the resonator, the loudspeaker and the battery respectively; a vibration part is arranged on the front surface of the vibration box, the resonator is arranged on the vibration part, and a resonant cavity is formed in the lower side of the vibration part; and the circuit board, the loudspeaker and the battery are all arranged in the vibration box. As the vibration box can provide a good protection effect for the circuit board, the loudspeaker and the battery, the circuit board, the loudspeaker and the battery are effectively prevented from being damaged, meanwhile, the resonator can drive the vibration part to vibrate, the resonant cavity provides a space for the vibration part to vibrate, and the vibration part is prevented from being damaged. The hard foreign body sensation of a user can be reduced while the good vibration effect is achieved, and the user experience is improved.

The application discloses a sound production device and an electronic equipment, wherein the sound production device comprises a shell and a sound production unit, the shell is provided with a containing cavity, a sound outlet and a resonance cavity, the sound production unit is arranged in the containing cavity, the sound production unit comprises a diaphragm, the diaphragm divides the containing cavity into a front sound cavity and a narrow rear sound cavity, the sound outlet is communicated with the front sound cavity, the rear sound cavity is configured as a closed structure, and the resonance cavity is provided with a communicating hole and communicated with the rear sound cavity through the communicating hole. The technical scheme of the application can improve the standing wave valley problem of the sound production device, thereby improving the flatness of the frequency response curve and improving the sound quality.

The utility model belongs to the technical field of musical instrument manufacturing, and particularly relates to a drum sound control device. Comprising a drum body which is internally provided with a resonance chamber, and further comprises a sliding disc tuning mechanism which comprises a sliding disc part arranged in the resonance chamber and an operation part used for controlling the sliding disc part; the utility model discloses a shutter type tuning mechanism. Comprising a shutter supporting ring matched with the interior of the resonance chamber, a plurality of shutter units evenly arranged above the shutter supporting ring in the horizontal direction, a linkage rod used for enabling the shutter units to be in linkage with one another and a driving and stopping part used for driving the shutter units to rotate and locking the shutter units to a specific angle. The utility model aims to provide the drum sound control device which realizes flexible adjustment of parameters such as drum sound timbre, tone and the like through the unique sliding disc tuning mechanism and the shutter type tuning mechanism so as to meet the requirements of playing different music.

Filter arrangement for a microphone module (100) with an acoustic input tube (105), wherein a cavity (106) is arranged as a resonance chamber between the input tube (105) and a region of the filter arrangement designed for connection to a microphone module (100) or to a device (102) with a microphone module (100), wherein a Helmholtz resonator is formed as an ultrasonic filter (1) through the cavity (106) and the input tube (105), which exhibits a resonance at a defined frequency, wherein the resonance chamber has a significantly larger diameter than the input tube (105) and / or an opening (103) in front of the microphone module (100) to cause a transverse resonance in addition to the Helmholtz resonance.