52 results about "Low frequency response" patented technology

The utility model relates to the technical field of sound boxes, in particular to an improved sound box, which comprises a box body and a front cover fixedly mounted on one side of the box body, a loudspeaker is fixedly arranged at the center of the inner side of the front cover, a small loudspeaker is fixedly arranged at the upper end of the inner side of the front cover, and a connecting block is fixedly arranged at the concentric position of the center of the outer side of the front cover and the loudspeaker. U-shaped blocks used for protecting the loudspeaker are symmetrically arranged in the connecting block up and down, damage of an external object to a vibrating diaphragm of the loudspeaker is prevented, the service life of the loudspeaker is prolonged, the U-shaped blocks can also be used as handles, a user can conveniently carry the loudspeaker box, and practicability is improved; the supporting plate is arranged in the annular groove, so that the structural strength is enhanced, the front cover is prevented from being deformed when being stressed, the resonance phenomenon in the annular groove is reduced, the overall tone quality performance of the sound box is improved, the sealing gasket ensures the tight attachment between the front cover and the box body, air leakage is prevented, and the low-frequency response and the overall tone quality clarity are improved.

The invention relates to the technical field of improvement of electroacoustic devices, and discloses a sound guide method for a non-in-ear earphone and a sound guide accessory thereof, and the method comprises the steps: collecting the spatial parameters of the earphone and an ear canal; the optimal gathering angle theta opt is calculated through the sound energy gathering angle optimization model, the sound guide path shape is optimized through the path loss minimization model so as to minimize Lpath, and finally sound guide accessories are manufactured and installed; the fitting comprises an adaptive interface part, an acoustic gathering part and a flexible sound conducting part, directional gathering and efficient conduction of sound energy are accurately controlled through a mathematical model, and on the premise that the non-in-ear earphone is kept painless and comfortable to wear, low-frequency response is remarkably improved, sound leakage is reduced, and sound quality details are improved; the technical contradiction between the poor tone quality of an open earphone and the strong discomfort of an in-ear earphone is effectively solved; the scheme is simple in structure, can be used as a universal accessory or integrally designed, and has wide applicability.

The utility model discloses a high-performance loudspeaker, which relates to the technical field of loudspeakers, comprises a loudspeaker box, and a voice coil, a magnetic group and a membrane group which are arranged in the loudspeaker box, and is characterized in that an accommodating space is arranged in the magnetic group, the accommodating space is communicated with the external space of the loudspeaker box, a passive radiator is arranged in the accommodating space, and the membrane group is communicated with the passive radiator. The passive radiator comprises a passive radiation mass block and a passive radiation vibrating diaphragm arranged on the periphery of the passive radiation mass block, and the passive radiation vibrating diaphragm is connected with the magnetic group. According to the utility model, through the structure of the magnetic circuit and the passive radiator, the performance of the loudspeaker is improved, and under the condition of the same rear cavity space, the loudspeaker has lower resonant frequency, better low-frequency response and larger sound radiation area, and can provide more loud sound.

According to the sound equipment system provided by the utility model, by optimizing the structural design of the sound equipment, the sound quality effect of the sound equipment is ensured, and meanwhile, the standard packaging size requirement is met. Firstly, the length of the bar-shaped sound box is controlled within 400mm, and the width and the height of the bar-shaped sound box do not exceed 90mm, so that the bar-shaped sound box can adapt to a compact packaging design, and sound channel arrangement and a sound field coverage range are not influenced. And secondly, the size of the bass sound box is limited within 400mm * 300mm * 150mm, so that the volume is reduced, enough low-frequency response can still be provided, and the requirement of a user on a bass effect is met. The size of the outer packaging box provided by the invention accords with the international general standard package size, so that the logistics transportation cost is reduced, and the storage and distribution efficiency is improved. Meanwhile, the structural design avoids the problem that a traditional sound box product needs to be packaged in a special shape due to the fact that the size is too large, not only is the universality of packaging improved, but also the market competitiveness is enhanced, and the product is convenient to sell and circulate in the global range.

The utility model discloses a parallel module with double independent front cavities, which relates to the technical field of loudspeakers and comprises an upper loudspeaker, a lower loudspeaker and a front cavity channel, the front cavity channel is arranged between the lower loudspeaker and the upper loudspeaker, and a front cavity isolation plate is arranged between the upper loudspeaker and the lower loudspeaker. The front cavity isolation plate, the upper loudspeaker and the lower loudspeaker are all connected with the peripheral supporting piece. According to the parallel module with the double independent front cavities, the front cavity channel is divided into the two independent cavities through the arrangement of the front cavity isolation plate, sound wave interference is eliminated, distortion is reduced, and the independent front cavities isolate vibration of the vibrating diaphragm, so that the problem of phase loss resonance distortion is effectively solved; the upper loudspeaker and the lower loudspeaker are arranged in parallel, so that the problem of insufficient sound pressure of small equipment is effectively solved, and the low-frequency response and the overall volume are remarkably enhanced; through the arrangement of the lower loudspeaker, the problem of weak low-frequency sound is effectively improved, and the low-frequency depth and elasticity are improved.

The invention belongs to the technical field of MEMS loudspeakers, and particularly relates to a preparation method of a PZT loudspeaker based on a back guide structure. Comprising the steps that a bottom electrode metal film and a PZT piezoelectric film are sequentially sputtered on the front face of a device at high temperature through a magnetron sputtering PVD technology; performing a bottom electrode layer structure photoetching process; performing a top electrode layer photoetching process; performing an upper and lower electrode isolation layer photoetching process, performing a front surface back guide hole structure photoetching process, and etching a top silicon layer of the SOI substrate material sheet through ICP (Inductively Coupled Plasma) to form a device back guide hole structure; depositing a Parylene protection material on the front side by a vacuum vapor deposition process; and performing a back photoetching process, and etching the back of the SOI substrate material sheet through ICP (Inductively Coupled Plasma) to form a device diaphragm cavity structure. According to the invention, the air circulation resistance of the rear cavity can be accurately controlled, the quality-spring property of the diaphragm can be matched, the rigidity and damping of the diaphragm can be balanced, the resonance peak can be effectively reduced, the low-frequency response bandwidth can be expanded, and the SPL can be improved.

The application discloses a MEMS loudspeaker device, system and preparation method driven by electrostatic and piezoelectric mixed driving, relates to the technical field of loudspeakers, and aims at solving the problems of high driving voltage, easy occurrence of suction effect and insufficient low-frequency response caused by single electrostatic driving mode of the prior art, and the problem of poor high-frequency response caused by single piezoelectric driving. The MEMS loudspeaker device comprises, from bottom to top, a substrate, an electrostatic driving unit formed on the substrate, at least a fixed electrode and a movable diaphragm of the electrostatic driving unit, and a piezoelectric driving unit integrated on the movable diaphragm. The piezoelectric driving unit receives a preset direct-current bias voltage of a preset size to control the movable diaphragm to generate a preset static displacement in the direction of the fixed electrode, and the piezoelectric driving unit processes middle-low frequency signals in input wide-band audio signals; the electrostatic driving unit processes high frequency signals in the wide-band audio signals. The application is used for improving loudspeaker quality of the loudspeaker and reducing power consumption.

The utility model belongs to the field of teaching conference consonants, particularly relates to a flat-panel sound box adopting an aluminum honeycomb double-surface vibration sound production board, and aims to solve the problems that in the prior art, in order to improve low-frequency response, a wave or honeycomb sandwich layer double-surface paperboard is generally adopted as a sound production surface, so that transient response is reduced, sound is not transparent enough, and the reduction degree is poor. According to the technical scheme, the sound box comprises a sound box body, the sound box body comprises a flat-panel sound box frame body, an aluminum honeycomb double-surface vibration sound production plate and a sound box back plate, the aluminum honeycomb double-surface vibration sound production plate and the sound box back plate are arranged on the two sides in the flat-panel sound box frame body respectively, and a driver is installed on the side, located in the flat-panel sound box frame body, of the aluminum honeycomb double-surface vibration sound production plate; an existing paper sandwich panel is replaced by the aluminum honeycomb double-surface vibration sound production plate, so that medium-high frequency extension of the loudspeaker can be expanded, a transparent and pure sound production effect is generated, and the loudspeaker has very high pressure resistance, and can effectively prevent deformation, moisture and mildew.

The application provides a semi-submersible platform air gap extreme value prediction system and method based on numerical simulation, relates to the technical field of numerical simulation, and obtains an air gap response sequence of a semi-submersible platform in a target water area through numerical simulation; extracts a low-frequency response from the air gap response sequence, carries out nonlinear correction on the low-frequency response based on a data-driven model, and obtains a corrected low-frequency response sequence; reconstructs the corrected low-frequency response sequence and a wave frequency response to obtain a composite air gap response sequence; carries out non-Gaussian extreme value statistics based on the composite air gap response sequence to obtain an air gap extreme value prediction result; and then obtains a test sequence of the air gap of the semi-submersible platform changing with time, and iteratively optimizes the data-driven model based on the difference between the test sequence and the air gap extreme value prediction result, so that the application can realize data-driven accurate correction of the low-frequency response in numerical simulation, and improve the air gap extreme value prediction accuracy of the semi-submersible platform.

The utility model discloses a single shell bone conduction MEMS microphone structure belongs to bone conduction MEMS microphone technical field. A single shell bone conduction MEMS microphone structure, including shell and PCB, the shell is installed at the top of PCB, and the bottom of PCB is provided with PAD, the outer surface of PCB is provided with MEMS, one side of MEMS is provided with ASIC, wherein, ASIC is connected with MEMS and PCB through gold wire respectively. To solve the existing bone conduction MEMS microphone when receiving the broadcast is susceptible to external air pressure, thereby appearing the problem of resonance peak, and the diaphragm appears the tailing effect, finally leads the problem of voice fuzzy, the inner air vent solves the static pressure balance problem, protects the diaphragm and guarantees long -term stability, and the design of the air vent of extending to the support ring and mass block gap, through the accurate control of air release, can optimize the low frequency response, and suppress unnecessary resonance peak.

The technique for operating a loudspeaker disposed within a sealed housing, executed by a data processing system, includes: obtaining a first input signal to be output by the loudspeaker; determining a first volume level associated with the first input signal; selecting a first Linkwitz transform and a first multi-band compressor (MBDRC) from volume-related configuration data based on the first volume level; generating a first intermediate signal to improve the low-frequency response of the loudspeaker by applying the first Linkwitz transform to the first input signal; applying the first MBDRC to the first intermediate signal to generate a first output signal by compressing at least a portion of the first intermediate signal; and driving the loudspeaker using the first output signal to produce a first audio output.

The application discloses a kind of based on three-stage cooperation of transmission and distribution self-adapting power grid low-frequency load shedding method and device, the method is by constructing wide-area measurement network when detecting low-frequency overrun, collection synchronous operation data, constructs multi-machine equivalent model, calculates initial total power shortage;Draw low-frequency response curve, calculate real-time frequency change rate, according to new energy access proportion judgment threshold interval, correct or directly adopt initial shortage value;According to accurate shortage value, by equal distribution algorithm is decomposed into distribution network partition load shedding and is issued, distribution network is again decomposed to district internet of things terminal;Terminal screening cuts off the non-important load of small frequency regulation effect, feedback actual cut-off amount;Transmission network dispatching center accumulates cumulative load shedding, judges whether frequency recovers safety threshold, recovers and terminates process, does not recover and does not reach maximum round then iteration estimation correction, until up to standard or complete full round cut-off.The application solves the problems of low power shortage estimation accuracy, inaccurate load shedding and other problems in the prior art.

The invention provides an adaptive equalizer circuit and an operation method thereof. The adaptive equalizer circuit includes an amplifier circuit and an adaptive circuit. The amplifier circuit is coupled to the adaptive circuit. The amplifier circuit receives an input signal. The amplifier circuit provides a compensation signal to the adaptive circuit based on an input signal. The adaptability circuit provides a compensation setpoint and a feedback signal to the amplifier circuit based on the compensation signal. A low-frequency response and a high-frequency gain of the amplifier circuit are adjusted based on the feedback signal and the compensation setpoint, respectively.

Aspects of acoustic transducers are described. One aspect is a microelectromechanical (MEMS) transducer comprising a substrate and multiple cantilevered beams. A first cantilevered beam comprises a first protrusion and a first piezoelectric structure, where the first piezoelectric structure comprises a first deflection end and a first fixed end, where the first fixed end is coupled to the substrate, and where the first deflection end is cantilevered away from the substrate. The first cantilevered beam is separated from a second cantilevered beam by a gap. The first protrusion is disposed at the first deflection end and increases a thickness of the first cantilevered beam along the gap at the first deflection end. A second protrusion of the second beam is disposed at a second deflection end and increases a thickness of the second cantilevered beam along the gap at the second deflection end.

The application relates to the technical field of sound wave detection, in particular to a sound vibration cavity sensing structure based on a porous array type PZT, which comprises a cavity, a piezoelectric ceramic film, a positive electrode and a negative electrode. The piezoelectric ceramic film is arranged on the opening of the cavity and is fixedly connected with the opening end of the cavity. A plurality of half-through holes are arranged on the piezoelectric ceramic film. The positive electrode is arranged on the outer surface of the piezoelectric ceramic film, and the negative electrode is arranged on the inner surface of the piezoelectric ceramic film. The material of the piezoelectric ceramic film is lead zirconate titanate. The application has higher sensitivity and better low-frequency response performance, and has a good application prospect in the technical field of sound wave detection.

The invention discloses a sound wave balanced automobile loudspeaker which comprises an outer support, a U-shaped iron is installed at the axial first end of the outer support, a large voice diaphragm is arranged at the axial second end of the outer support, a first pole piece and a first permanent magnet are installed in the U-shaped iron, and a large voice coil is arranged between the first permanent magnet and the U-shaped iron in the axial direction. A magnetic cup is installed on the axial upper side of the permanent magnet, an inner support is embedded in the magnetic cup, a magnetic conductive ring is installed in the inner support, a second pole piece and a magnetic ring are installed on the inner side of the magnetic conductive ring, a second permanent magnet is installed on the upper side of the magnetic ring, a small voice coil covers the upper side of the second permanent magnet, and a small voice diaphragm is installed between the outer side of the small voice coil and the inner support. A sound wave equalizer located on the upper side of the small voice coil is installed in the middle of the large voice diaphragm. The problems that an existing automobile loudspeaker is difficult to give consideration to high and low frequency responses at the same time, low-frequency turbidity, high-frequency harsh or tone quality faults easily occur, and the broadband tone quality requirement cannot be met are solved.

The utility model discloses a circular bone conduction vibrator which comprises a shell, a vibrating membrane, a permanent magnet and a driving coil, the shell is arranged to be in a circular ring shape, the vibrating membrane is arranged at the position, close to the top, in the shell, the driving coil is arranged at the position, close to the bottom, in the shell, and the vibrating membrane and the driving coil are arranged in an opposite mode. The permanent magnet is installed in the shell, the permanent magnet is arranged between the vibrating diaphragm and the driving coil, and the permanent magnet and the driving coil are oppositely arranged. According to the utility model, through the circular design, the vibrator structure is compact, miniaturization and integration are facilitated, and the wearing comfort is improved; the flexible vibrating diaphragm and the multi-layer wound driving coil are adopted, so that the low-frequency response and energy conversion efficiency are remarkably improved, and the tone quality is improved; the use of the high magnetic energy product permanent magnet enhances the magnetic field force, and improves the vibration effect and sound transmission efficiency of the vibrator.

The application relates to a kind of double-mechanism broadband vibration reduction methods based on local resonance and nonlinear damping of superhull, comprising: constructing linear vibrator for suppressing the low-frequency response peak of target shell using local resonance band gap;Linear vibrator includes: support structure, mass bin and linear mass unit;Replace linear mass unit with nonlinear mass unit of equal mass to obtain nonlinear vibrator;Construct a nonlinear damping effect model for nonlinear vibrator, used to optimize the adjustment parameters of nonlinear mass unit;Based on the setting of adjustment parameters, array the nonlinear vibrator on the target shell;Establish a vibration reduction prediction model for vibration reduction performance, and if the predicted vibration reduction performance meets the preset requirements, output the obtained nonlinear vibrator and its array mode for vibration reduction control of the target shell.The scheme realizes the double-mechanism coupling effect of local resonance band gap and nonlinear damping, and meets the demand of broadband vibration control.

The invention relates to the technical field of high polymer materials, in particular to a low-frequency response degradable self-reinforced piezoelectric composite material and a preparation method thereof. The self-reinforced piezoelectric composite material is prepared from the following components: stereocomplex polylactic acid and hydroxyapatite, the content of the hydroxyapatite is 5-30 wt% of the content of the stereocomplex polylactic acid; the low-frequency response degradable self-reinforced piezoelectric composite material has a mesoporous structure. The crystal of the degradable self-reinforced piezoelectric composite material with low-frequency response is a 100% stereocomplex crystal, and has excellent piezoelectric property.

A low-frequency optical fiber acceleration sensor provided by the present invention comprises a bottom plate, a sensing body and a cover body, the sensing body is arranged on the bottom plate, the sensing body comprises a connecting plate, a central cabin is arranged on the connecting plate, a first flexible carrier plate is arranged in the central cabin, a first end of the first flexible carrier plate is fixedly connected with the central cabin, and a second end of the first flexible carrier plate is fixedly connected with the cover body. A first rigid mass block is fixedly arranged at the second end of the first flexible carrier plate and can swing left and right relative to the first end of the first flexible carrier plate, a first fiber bragg grating is arranged on the left side face of the first flexible carrier plate, and a second fiber bragg grating is arranged on the right side face of the first flexible carrier plate. The first fiber bragg grating and the second fiber bragg grating extend along the length direction of the first flexible carrier plate; the cover body is connected to the upper portion of the connecting plate and used for sealing the central cabin body. The problems that an existing acceleration sensor is poor in low-frequency response, prone to electromagnetic interference, poor in corrosion resistance, insufficient in sensitivity and the like in ocean engineering application are solved.

The application belongs to the technical field of ground-air electromagnetic detection, and specifically relates to a damping-self-integration integrated ground-air frequency domain electromagnetic wideband receiving system and method, which comprises: a hollow coil sensor for sensing a ground magnetic field signal and outputting an induced electromotive force based on a Faraday electromagnetic induction law; an active integration circuit connected with the output end of the hollow coil sensor through an input end and used for analog integration compensation of the induced electromotive force; a signal conditioning unit used for gain adjustment, high-frequency noise filtering and power frequency noise notch processing of the integrated voltage signal, and output of a conditioned analog voltage signal; and a signal acquisition unit used for conversion of the conditioned analog voltage signal into a digital signal and execution of an acquisition action in response to an external synchronous trigger signal. The application improves the low-frequency response characteristic of the coil, so that the amplitude of a low-frequency signal reaches the same level as that of a high-frequency signal.

The invention discloses an MEMS microphone and a forming method thereof, and the MEMS microphone comprises a first substrate which is internally provided with a first cavity with an opening along the substrate surface of the first substrate, and the depth of the first cavity is smaller than the thickness of the first substrate; the back polar plate is located on the substrate surface of the first substrate and covers the opening of the first cavity, and a first acoustic air hole is formed in the position, corresponding to the opening covering the first cavity, in the back polar plate; the second substrate is internally provided with a second cavity, the part, at the bottom of the second cavity, of the second substrate serves as a vibrating diaphragm, the second substrate is in bonding connection with the first substrate, an opening of the first cavity is opposite to an opening of the second cavity, and the second cavity is communicated with the first cavity through a first acoustic air hole; the first cavity and the second cavity jointly form a reference pressure cavity which is sealed in an airtight mode. According to the MEMS microphone, the defects that a traditional MEMS microphone is poor in low-frequency response and prone to being interfered and has reliability risks are overcome.

The invention discloses a novel L-shaped multi-dimensional broadband piezoelectric energy collection device, and belongs to the technical field of piezoelectric energy collection. The novel L-shaped multi-dimensional broadband piezoelectric energy collection device comprises a piezoelectric cantilever beam, a branch beam and a base which are connected through screw assemblies; the piezoelectric cantilever beam comprises a vertical main beam, a piezoelectric plate, a main beam first mass block and a main beam second mass block; the branch beams comprise a first branch beam, a second branch beam, a third branch beam and a branch beam mass block; the base comprises an angle support and a pressing piece. The novel L-shaped multi-dimensional broadband piezoelectric energy collection device has the advantages of small size, high conversion efficiency, low-frequency response, broadband characteristic and multi-direction vibration response capability, and can realize multi-direction energy collection capability and high output power; the problems that a piezoelectric vibration energy collecting device is narrow in effective working frequency band and insufficient in environment robustness are solved.

The utility model provides a sound box with resonance cavity, the sound box includes box, guide sound pipe, speaker and passive radiator, the box has the inner chamber, passive radiator is located the side of box, the guide sound pipe is located in the box and the guide sound pipe with the box between interval forms the resonance cavity, the guide sound pipe extends to passive radiator direction and the sound outlet of guide sound pipe is close to and towards passive radiator, the guide sound pipe front is equipped with the entrance, the speaker is located on the box and its front radiation surface is towards the front of box, the rear end of speaker is from the entrance and is placed into the guide sound pipe. The utility model can improve the stereo effect of sound box in low frequency response.

The invention provides a semi-submersible platform air gap extremum forecasting system and method based on numerical simulation, and relates to the technical field of numerical simulation, and the method comprises the steps: obtaining an air gap response sequence of a semi-submersible platform in a target water area through numerical simulation; extracting low-frequency response from the air gap response sequence, and performing nonlinear correction on the low-frequency response based on a data driving model to obtain a corrected low-frequency response sequence; reconstructing the corrected low-frequency response sequence and the wave frequency response to obtain a composite air gap response sequence; performing non-Gaussian extremum statistics based on the composite air gap response sequence to obtain an air gap extremum prediction result; according to the method and the device, the test sequence of the air gap of the semi-submersible platform along with the time change is obtained, the data driving model is iteratively optimized on the basis of the difference between the test sequence and the air gap extreme value prediction result, and the data driving type accurate correction aiming at the low and medium frequency response in numerical simulation can be realized, so that the air gap extreme value prediction accuracy of the semi-submersible platform is improved.

The utility model relates to the technical field of loudspeakers, in particular to a loudspeaking device, which comprises a loudspeaker module and a loudspeaker, a containing cavity is divided into a first cavity and a second cavity by the loudspeaker, the loudspeaker module comprises a lower shell and an upper shell which are connected, the second cavity is provided with a phase inversion channel, and the lower shell is provided with a loudspeaker. The loudspeaker module comprises an upper shell and a lower shell, the lower shell is provided with a phase inversion channel, the phase inversion channel is shared with the upper shell and / or the lower shell, one end of the phase inversion channel is communicated with the second cavity, the other end of the phase inversion channel is communicated with the outside, and the lower shell is provided with a sound outlet communicated with the first cavity. Therefore, the space of the accommodating chamber occupied by the inverter tube in the traditional design is released, more abundant installation positions are provided for other key components, and the low-frequency response of the loudspeaker system can be improved.

The utility model relates to the technical field of loudspeakers, in particular to a loudspeaker with an independent sound cavity, which comprises a basin frame, a vibrating diaphragm, a voice coil, a magnetic circuit mechanism and a rear cavity, and the rear cavity is covered and hermetically welded on the periphery of the basin frame, so that the independent sound cavity is formed between the inner cavity of the rear cavity and the bottom of the basin frame. Air leakage caused by a gap generated between the rear cavity and the basin stand is avoided, and the product quality is improved; besides, the side face of the rear cavity is provided with the first sound outlet hole, the bottom of the rear cavity is provided with the second sound outlet hole, the equivalent acoustic impedance of the independent sound cavity can be effectively reduced, low-frequency energy is more effectively radiated to the external space, low-frequency response is extended, sound waves are diffused towards the first sound outlet hole of the rear cavity and complemented with downward radiation of the second sound outlet hole in the bottom face, and the sound effect is improved. Excessive concentration of sound in the vertical direction is reduced, the sound field is more stereoscopic, diffusion is more uniform, low-frequency diving and sound field uniformity and efficiency are effectively improved, and user requirements are met.

The invention discloses an anti-sound-output three-magnet coaxial double-unit flat-panel loudspeaker which comprises a frequency division PCB, a tuning net, a rear cover, a sound production structure, a large loudspeaker middle magnet, a large loudspeaker outer magnet, a bottom washer, a high-pitch voice coil, a high-pitch annular magnet, a vibrating diaphragm shell, a high-pitch upper annular magnet, a high-pitch middle magnet and a high-pitch vibrating diaphragm. The high-pitch bracket is fixedly connected with a bracket support, the bracket support is fixedly connected with a sounding structure, the sounding structure comprises a bottom washer, the bottom washer is fixedly connected with the bracket support, the bottom washer is sleeved with a high-pitch annular magnet, the bottom washer is provided with a high-pitch voice coil, the high-pitch annular magnet is provided with a vibrating diaphragm shell, and the vibrating diaphragm shell is internally and fixedly connected with a high-pitch vibrating diaphragm; by designing a core sounding structure, the problems of insufficient high and low frequency response and weak collaboration of an existing loudspeaker are solved, precise matching and complementary sounding of high and low pitch units are realized, signal interference and phase problems are avoided, and tone quality coordination and positioning accuracy are improved.

According to the sound box, the multimedia equipment and the electronic device disclosed by the invention, when the sound box is independently used, the opening and closing mechanism closes the communication port, so that external environmental factors such as dust and water vapor can be effectively prevented from invading into the shell, and the loudspeaker unit and an internal circuit are prevented from being affected with damp or accumulated. When the sound box is carried on an external electronic device (such as a vehicle), the opening and closing mechanism opens the communication port, so that an internal sound cavity of the sound box is communicated with an external device space, and an expanded acoustic resonance structure is formed. By increasing the volume of the effective sound cavity, the radiation efficiency of low-frequency sound waves can be remarkably enhanced, the low-frequency response characteristic is improved, and the layering sense and the dynamic range of the overall sound quality are improved. The switchable design of the opening and closing mechanism enables the sound box to meet the requirements of two scenes of independent use and external carrying, the adaptation of different acoustic characteristics can be realized without additional structural change, and the function integration and practicability of the sound box are improved.

Disclosed are an electronic device and method for performing voice recognition. An electronic device and method for performing voice recognition may comprise the steps of: receiving a voice signal from a user; analyzing a frequency response of the received voice signal to obtain a feature vector of a wake-up word and a low-frequency response less than a preset frequency in the frequency response; comparing the obtained low-frequency response with a low-frequency response less than a preset frequency pre-stored in a memory of the electronic device, on the basis of identifying whether the obtained feature vector of the wake-up word corresponds to a feature vector of a wake-up word pre-stored in the memory of the electronic device; determining whether a distance between the user and the electronic device is within a preset distance on the basis of a result of the comparison; and performing an operation corresponding to the voice signal on the basis of a result of the determination.