134 results about "Low frequency response" patented technology

The invention discloses a moving-coil geophone zero-phase corrector based on a state variable shaper. The zero-phase corrector comprises a state variable shaper, a differential-to-single-ended module and a single-ended-to-differential module. After a moving-coil geophone signal is input into a differential signal, the signal is converted into a single-ended signal suitable for filtering through the differential-to-single-ended module, and a high-pass filter, a band-pass filter and a low-pass filter in the state variable shaper correct the phase characteristic of the frequency response of the geophone to a zero-phase attribute. And finally, the single-ended to differential module converts the single-ended signal into a differential signal again and outputs the differential signal. The phase characteristic correction method can be used for phase characteristic correction of differential signals of the moving-coil geophone, low-frequency response can be expanded while the phase is corrected by changing resistance value adjustment, gain stability in the original bandwidth is kept, phase characteristic correction is provided for output of the moving-coil geophone with different frequencies and amplitudes, and the correction precision of the moving-coil geophone is improved. And the accuracy of the detector signal phase is improved.

The invention discloses intelligent sound equipment, and relates to the technical field of sound equipment, the intelligent sound equipment comprises a shell, a first partition plate, a second partition plate, a high-frequency loudspeaker, a full-frequency loudspeaker and a radiation unit, and the shell is provided with an accommodating cavity; the first partition plate and the second partition plate are arranged in the containing cavity at intervals so as to divide the containing cavity into a high-frequency cavity, an intermediate-frequency cavity and a low-frequency cavity which are sequentially arranged, the size of the high-frequency cavity is smaller than that of the intermediate-frequency cavity, the size of the intermediate-frequency cavity is smaller than that of the low-frequency cavity, and the high-frequency loudspeaker is arranged in the high-frequency cavity. The full-frequency loudspeaker is arranged in the intermediate-frequency cavity, the second partition plate is provided with a frequency division unit communicated with the intermediate-frequency cavity and the low-frequency cavity, the frequency division unit is used for scattering and absorbing medium-high frequency sound waves and keeping propagation of low-frequency sound waves, and the radiation unit is arranged in the low-frequency cavity; the radiation unit is used for receiving low-frequency sound waves which are emitted by the full-frequency loudspeaker and are transmitted to the low-frequency cavity through the frequency division unit so as to enhance low-frequency response.

The invention relates to an in-ear earphone with a caisson structure, and the earphone comprises a front cavity shell which is provided with a front cavity and a sound outlet communicated with the front cavity, and the sound outlet is sleeved with an earcap; the rear cavity shell is provided with a rear cavity communicated with the front cavity, a caisson structure part is arranged in the rear cavity and comprises an upper-layer caisson structure, a middle-layer caisson structure and a lower-layer caisson structure which are sequentially connected, the middle-layer caisson structure is located on the outer side of the upper-layer caisson structure, and the diameter of the middle-layer caisson structure is larger than that of the upper-layer caisson structure; the lower-layer caisson structure is located outside the middle-layer caisson structure and is larger than the middle-layer caisson structure in diameter; the sound production unit is arranged in the front cavity and the rear cavity; the caisson structure part is arranged in the rear cavity, the cavity is formed between the caisson structure part and the sound production unit, upward diffusion of sound is avoided, the sound gathering effect is achieved by scientifically applying the acoustic phase inversion hole principle, and meanwhile in order to enhance low-frequency response and improve sound quality, the phase inversion hole enables the bass to be cleaner and reduces distortion by reducing back wave reflection of the bass unit.

The invention provides a hierarchical pore sound-absorbing microsphere, a preparation method thereof and a sound-absorbing device. The method for preparing the hierarchical pore sound-absorbing microspheres comprises the following steps: uniformly mixing a zeolite molecular sieve, an inorganic binder, a water-soluble polymer material, a coagulant and an inorganic solvent, and adjusting to acidity to obtain mixed slurry, the water-soluble polymer material having a thermal swelling characteristic; dropwise adding the mixed slurry into a hot oil column by using a liquid drop generator, and heating and curing to obtain composite microspheres; and calcining the composite microspheres to obtain the hierarchical porous sound-absorbing microspheres. The prepared hierarchical-pore sound-absorbing microspheres comprise rich micropores, mesopores and macropores, the air compliance of the microspheres can be obviously improved, air can enter and exit the micropores more smoothly and quickly, the actual use efficiency of the micropores is improved, and therefore the low-frequency response is improved; the hierarchical-pore sound-absorbing microspheres prepared by the method are good in sphericity degree and not prone to powder falling due to friction, the production cost is low, the method is easy to implement and operate, and industrial mass production is facilitated.

The invention relates to the technical field of wave-absorbing materials, in particular to an array type flaky carbonyl iron composite PDMS flexible wave-absorbing film and a preparation method thereof. PDMS is used as a matrix, flaky carbonyl iron is used as a filler, and the flaky carbonyl iron is regularly arranged in an array manner in the radial direction of the matrix; and the wave-absorbing response frequency band when RL is less than or equal to-5 dB is 2.7-18.0 GHz, so that the absorption of low-frequency S / C wave band electromagnetic waves is enhanced. The preparation method comprises the following steps: weighing PDMS, adding a solvent, magnetically stirring uniformly, and then adding a curing agent to obtain a precursor solution; preparing a flaky carbonyl iron dispersion liquid; adding the precursor solution into the flaky carbonyl iron dispersion liquid, and mechanically stirring until the solution is in a homogeneous state; and transferring the mixed solution to a mold, carrying out vacuum degassing, applying a uniform magnetic field, heating and curing to obtain the array type flaky carbonyl iron composite PDMS flexible film. The technical problems of weak low-frequency response and narrow wave-absorbing frequency band of the wave-absorbing material are solved.

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 provides a piezoelectric structure, a cantilever type microphone and a preparation method of the piezoelectric structure, and relates to the technical field of semiconductors. The piezoelectric structure comprises a piezoelectric composite laminated layer, the surface of the piezoelectric composite laminated layer is provided with at least one groove group, the groove group comprises at least two grooves, and the at least two grooves are sequentially arranged along a direction opposite to a first direction and are communicated with each other; in the direction opposite to the first direction, the width of the previous groove is larger than that of the next groove, and one side face of the previous groove is flush with one side face of the next groove. According to the piezoelectric structure, the stepped groove group is arranged in the piezoelectric composite laminated layer, so that the gap of which the width is smaller than that of the groove is formed in the piezoelectric composite laminated layer. During processing, the width of a single groove is not required to be as small as possible, so that a gap with the width as small as possible can be easily obtained. The smaller the width of the gap is, the wider the low-frequency response of the cantilever type microphone is.

A high-penetrating-power audio amplifying circuit is provided with a first amplifying module, a second amplifying module and a third amplifying module, and the second amplifying module is connected with the first amplifying module and the third amplifying module. The high-penetrating-power audio amplifying circuit is provided with the amplifying modules, each amplifying module is a channel, that is, the high-penetrating-power audio amplifying circuit is provided with three-channel output, and the three-channel output can effectively control the gain of each channel, so that the output is more balanced, and as many as three loudspeakers can be driven; a better stereophonic effect, stronger low-frequency response and higher-quality music experience are achieved, the penetrating power of audio output can be effectively improved, and the stability and reliability of output power are greatly improved. Compared with a dual-channel output audio power amplification circuit in the prior art, the audio power amplification circuit provided by the utility model has higher penetrating power and is suitable for being used in an open outdoor environment.

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.

A method for optimizing acoustic performance in listening spaces addresses limitations in room acoustics for music production and reproduction. The method comprises two optimization steps: a multi-objective room optimization method applicable to any room shape and a multi-objective treatment optimization method that iteratively searches a library of potential acoustical treatments to determine optimal solutions for each accessible area. The method utilizes a multi-objective search engine to simultaneously optimize several critical acoustic metrics, including low-frequency response, spatial variation around listening positions, early reflections, modal temporal decay, and mid-to-high-frequency reverberation time. The integration of both optimization methods provides comprehensive acoustic control across the entire audible spectrum.

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.

Techniques are provided for generating sound using a speaker mounted to an enclosure (e.g., speaker cabinet) wherein a gas pressure level (e.g., air pressure level) inside the enclosure is lower than an ambient air pressure level outside the enclosure. The reduced gas pressure level within the enclosure provides an environment with a reduced pressure level at a back side of a speaker cone of the speaker, which enhances a low frequency response for a given speaker size, while also minimizing resonant frequencies and phase cancellation issues which could otherwise occur with conventional speaker systems in which acoustic sound waves are generated at the back side of the speaker cone. A pressure compensation system is utilized counteract a force applied to the front side of the speaker cone as a result of the gas pressure level inside the enclosure being lower than the ambient air pressure level outside the enclosure.

The utility model discloses a double panel unit module and an earphone, the double panel unit module comprises a support and two panel units, the support is provided with an upper installation groove and a lower installation groove, the two panel units are respectively installed in the upper installation groove and the lower installation groove, and the two panel units are horizontally and symmetrically arranged up and down. Through the two panel units which are horizontally and symmetrically arranged up and down, mutual interference of vibration can be reduced, low-frequency response can be improved, meanwhile, due to the fact that the two panel units are symmetrically arranged and sound pressure is overlapped, a higher sound pressure level is generated, the propagation intensity of sound energy on a unit area is increased, sound is made to be stronger and clearer, and the sound quality is improved. And the sound pressure level of the unit is improved, so that a high-strength signal can be better processed, the accuracy and fidelity of the signal are improved, and the occurrence of dynamic distortion is reduced.

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 invention discloses a vehicle-mounted door loudspeaker module, a vehicle-mounted sound system and a vehicle, the vehicle-mounted door loudspeaker module comprises a mounting frame, a loudspeaker unit and an acoustic waveguide structure, the mounting frame is provided with a mounting plate, and the mounting plate is used for fixedly connecting the vehicle-mounted door loudspeaker module with the mounting position of a vehicle door metal plate; the main plane of the mounting plate is parallel to the plane where the mounting position is located, the loudspeaker unit is fixed in the mounting frame and comprises a vibrating diaphragm, the vibrating diaphragm and the mounting frame define a front sounding cavity, and the included angle between the axis of the loudspeaker unit and the main plane of the mounting plate is smaller than a preset angle, so that resonance between the vibration assembly and a vehicle door metal plate during vibration is avoided; and the sound waveguide structure is arranged in the sound production front cavity, so that the cavity volume of the sound production front cavity is reduced, the harmonic peak is weakened, the resonant frequency is migrated to high frequency, the overall bandwidth is expanded, the influence of the front cavity effect on the low-frequency-band sound quality is weakened, and the uniformity of low-frequency response is improved.

The invention discloses a vibrating diaphragm assembly, a sound production device and electronic equipment. The vibrating diaphragm assembly comprises a ball top part located in the center position and a folding ring part arranged on the outer side of the ball top part in the circumferential direction, the ball top part and the folding ring part at least comprise one crosslinkable high polymer material layer of the same type, the thickness of the ball top part is larger than that of the folding ring part, the crosslinking degree of the ball top part is 50%-100%, and the thickness of the folding ring part is larger than that of the ball top part. And the crosslinking degree of the folding ring part is 0-20%. By controlling different crosslinking degrees of the ball top part and the folding ring part, the requirements of high rigidity of the ball top part and high flexibility of the folding ring part are met. The rigidity of the ball top is high, segmentation vibration is not prone to occurring in the high-frequency vibration process, and high-frequency response is good. The cross-linkable high polymer material layer of the folding ring part does not generate cross-linking or low-degree cross-linking, so that the high polymer material can keep flexibility, and the folding ring part is small in Young modulus and good in low-frequency response.

The present invention discloses a sound pickup comprising at least two diaphragms and a sound pickup processing module. The at least two diaphragms each pick up sound waves of different target frequency bands and are connected to the sound pickup processing module. By selecting different diaphragms to specifically pick up sound waves of different frequency bands, the present invention enables each diaphragm to utilize its characteristics that are most suitable for picking up the frequency band. This solves the problem of existing sound pickups being either too sensitive and unsuitable for high-noise environments, or too lightweight, having low sensitivity, and poor high and low frequency response. This also achieves the technical effect of improving sound fidelity and preventing interference.

The present application provides a method and system for detecting anomalies in the performance data of electronic control module components. Among them, the method applies an alternating electric field to the electronic control module components through non-contact electrodes, collects the energy loss, capacitance change and polarization delay data of the dielectric response, and extracts the ion migration, molecular steering and impurity conductivity characteristics from them; constructs a multi-band aging feature library based on accelerated aging experiments, including low-frequency delay, medium-frequency turning and high-frequency loss change rate characteristics; when it is detected that the low-frequency response slows down, the medium-frequency characteristics shift to the left and the high-frequency loss increases sharply, it is determined that the component has undergone electrochemical aging, and accurate diagnosis is achieved. The present application significantly improves the detection accuracy and reliability of electrochemical aging anomalies of electronic control module components through collaborative analysis of multi-band dielectric response characteristics.

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 invention relates to the technical field of force sensors, and discloses a six-dimensional force sensor comprising a mounting seat; the cover plate can rotate around a first direction and a second direction relative to the inner core to drive the inner core to rotate around a third direction and move along the first direction, the second direction and the third direction; a first rotary connection assembly; the first tangential force sensitive core body is used for detecting a first tangential force; a second rotary connection assembly; the second tangential force sensitive core body is used for detecting a second tangential force; the third tangential force sensitive core body is used for detecting a third tangential force; the force transmission piece is arranged on the inner core in a sleeving manner; the first direction force sensitive core body is used for detecting a first acting force; the second direction force sensitive core body is used for detecting a second acting force; the second force transmission piece is fixed on the movable piece; and the third direction force sensitive core body detects the third acting force. According to the six-dimensional force sensor disclosed by the invention, the defects of low detection precision, poor creep resistance, low frequency response and remarkable temperature drift of a strain gauge type six-dimensional force sensor are improved.

Techniques performed by a data processing system for operating a speaker disposed within a sealed enclosure herein include obtaining a first input signal to be output by the speaker; determining a first volume level associated with the first input signal; selecting a first Linkwitz Transform and a first Multiband Compressor (MBDRC) from volume-dependent configuration data based on the first volume level; generating a first intermediate signal by applying the first Linkwitz Transform to the first input signal to increase a low-frequency response of the speaker; generating a first output signal by applying the first MBDRC to the first intermediate signal by compressing the at least a portion of the first intermediate signal; and driving the speaker to produce first audio output using the first output signal.

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 invention relates to a low-frequency response test method for a lithium niobate phase modulator based on a fiber-optic gyroscope, belongs to the technical field of fiber-optic gyroscopes, and solves the problem that the frequency response of the lithium niobate phase modulator at the low frequency is difficult to measure in the prior art. A digital quantity corresponding to the 2pi phase voltage of the lithium niobate phase modulator; s2, setting the fiber-optic gyroscope under a static and open-loop working condition; s3, the multiple fixed step waves and the bias modulation signals are applied to the lithium niobate phase modulator, and the fixed step waves correspond to different phase modulator modulation frequencies; s4, calculating to obtain an ideal phase difference; the actual phase difference is measured; and S5, comparing the ideal phase difference with the actual phase difference to obtain an electro-optical response characteristic of the lithium niobate phase modulator under a low-frequency condition, and taking the electro-optical response characteristic as a test result.

The present invention discloses an in-ear earphone with a caisson structure, comprising: a front cavity shell, comprising a front cavity and a sound outlet connected to the front cavity, wherein the sound outlet is sleeved with an earmuff; a rear cavity shell, comprising a rear cavity connected to the front cavity, wherein a caisson structure part is arranged in the rear cavity, wherein the caisson structure part comprises an upper caisson structure, a middle caisson structure and a lower caisson structure connected in sequence, wherein the middle caisson structure is located outside the upper caisson structure, and its diameter is larger than that of the upper caisson structure, and the lower caisson structure is located outside the middle caisson structure, and its diameter is larger than that of the middle caisson structure; a sound-emitting unit is arranged in the front cavity and the rear cavity; by arranging the caisson structure part in the rear cavity, a cavity is formed between the caisson structure part and the sound-emitting unit, thereby preventing the sound from diffusing upward, and scientifically applying the principle of acoustic inverted holes to play a role in gathering sound, and at the same time, in order to enhance the low-frequency response and improve the sound quality, the inverted holes reduce the back wave reflection of the bass unit, thereby making the bass cleaner and reducing distortion.

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 invention relates to the technical field of optoelectronic device modeling, in particular to a thin film lithium niobate phase modulator low-frequency response analysis method which comprises the steps that equivalent RC branches are established for an upper cladding layer, a lithium niobate waveguide layer and a substrate layer of a thin film lithium niobate phase modulator respectively, and an RC network structure is established through the equivalent RC branches; extracting the structure and electrical parameters of the thin film lithium niobate phase modulator and determining the initial value of an RC element in the RC network structure; determining a node voltage state model based on the RC network structure, solving the node voltage state model, and obtaining system response; based on the system response and the RC network structure, effective voltage, characteristic relaxation time and low-frequency drift amplitude are determined to serve as low-frequency response of the thin-film lithium niobate phase modulator; according to the invention, corresponding physical interpretability analysis of the device can be realized.