Low-cut adjustment microphone system

Abstract

The invention discloses a low-switching adjustment microphone system, and relates to the technical field of microphone sound adjustment, and the low-switching adjustment microphone system comprises a sound collection interface, a first filter circuit, a low-switching circuit and an audio output interface. Firstly, a sound collection device converts a collected sound signal into a first sound electric signal and inputs the first sound electric signal into a system through a sound collection interface, and the sound collection interface receives current fed back by an audio output interface at the same time to supply power to the sound collection device; an input first sound electric signal is transmitted to the first filter circuit for processing; the first filter circuit can adjust the filter frequency according to the actual demand under the regulation and control of the low-cut circuit, and carries out the filtering processing of a specific frequency component in the first sound electric signal. And the processed signal is transmitted to external equipment through the audio output interface, so that the technical problem of how to realize a microphone low-frequency noise processing function suitable for different scenes is solved.

Description

Technical Field

[0001] The invention relates to the technical field of microphone sound adjustment, and in particular to a low-cut adjustment microphone system. Background Art

[0002] With the rapid development of audio content such as live broadcasts, short videos, and podcasts, the quality requirements for audio recording are getting higher and higher. In the recording process in different scenarios such as professional recording studios, outdoor interviews, and live broadcasts, due to the influence of many factors such as the environment and equipment, low-frequency noise interference often occurs, such as air-conditioning unit vibration, traffic noise, wind noise and other environmental noise. These interferences will seriously affect the clarity and professionalism of the recording and reduce the overall quality of the audio work. Therefore, during the audio recording process, the audio signal needs to be professionally processed to obtain higher quality audio effects.

[0003] Current audio processing generally uses dedicated digital signal processing (DSP) chips to achieve low-cut and gain control of audio signals. In this solution, the audio signal is first acquired by the acquisition device and then input into the DSP chip for processing. The DSP chip processes the input audio signal according to the preset frequency parameters through the built-in EQ equalization tool. In specific implementation, the DSP chip will set a frequency point internally and attenuate or filter the audio signal below this frequency point to achieve the low-cut function. This DSP-based processing solution uses digital signal processing technology to complete the low-frequency control of the audio signal.

[0004] However, in actual applications, DSP chips are expensive and require special programming and debugging processes. At the same time, DSP chips consume relatively large amounts of power, which significantly increases the battery burden in portable devices. In addition, since analog-to-digital conversion and digital-to-analog conversion are required during DSP chip processing, additional delays and noise may be introduced during signal transmission. Especially in scenarios with high real-time requirements, this delay may affect the immediacy of recording and the effect of audio processing, giving users an undesirable user experience. Summary of the invention

[0005] The main purpose of the present invention is to propose a low-cut adjustment microphone system, aiming to solve the technical problem of how to realize the low-frequency noise processing function of the microphone adapted to different scenarios.

[0006] To achieve the above-mentioned object, the present invention provides a low-cut adjustment microphone system, the low-cut adjustment microphone system comprising: a sound collection interface (10), a first filter circuit (20), a low-cut circuit (30) and an audio output interface (40);

[0007] The sound collection interface (10) is connected to the first filter circuit (20) and the audio output interface (40), and the low-cut circuit (30) is connected to the first filter circuit (20);

[0008] The sound collection interface (10) is used to collect a first sound electrical signal and transmit the first sound electrical signal to the first filter circuit;

[0009] The low-cut circuit (30) is used to adjust the filtering frequency of the first filtering circuit (20);

[0010] The first filtering circuit (20) is used to filter the first sound electrical signal at a currently set frequency, and send the filtered first sound electrical signal to the audio output interface (40);

[0011] The audio output interface (40) is used to send the first sound electrical signal after filtering to the external device.

[0012] In one embodiment, the low-cut adjustment microphone system further comprises: a gain adjustment circuit (50);

[0013] The gain adjustment circuit (50) is connected to the output end of the sound collection interface (10);

[0014] The gain adjustment circuit (50) is used to adjust the signal amplitude of the first sound electrical signal.

[0015] In one embodiment, the low-cut circuit (30) comprises: a first switch unit (301) and a low-cut unit (302);

[0016] One end of the first switch unit (301) is connected to the first filter circuit (20), and the other end of the first switch (SW1) is connected to the low-cut unit (302);

[0017] The low-cut unit (302) is used to adjust the filtering frequency of the first filtering circuit (20);

[0018] The first switch unit (301) is used to control the connection between the low-cut unit (302) and the first filter circuit (20).

[0019] In one embodiment, the gain adjustment circuit (50) comprises: a second switch unit (502) and a gain adjustment unit (501);

[0020] The second switch unit (502) is connected to the gain adjustment unit (501), and the gain adjustment unit (501) is connected to the output end of the sound collection interface (10);

[0021] The second switch unit (502) is used to adjust the gain of the gain adjustment unit (501);

[0022] The gain adjustment unit (501) is used to adjust the signal amplitude of the first sound electrical signal according to the currently set gain.

[0023] In one embodiment, the audio output interface (40) comprises: a third switch unit (401), a mobile phone interface (402) and a camera interface (403);

[0024] One end of the third switch unit (401) is connected to the output end of the sound collection interface (10), and the other end of the third switch unit (401) is connected to the mobile phone interface (402) and the camera interface (403);

[0025] The camera interface (403) is used to connect to a camera and transmit the first sound electrical signal to the camera;

[0026] The mobile phone interface (402) is used to connect to a mobile phone and transmit the first sound electrical signal to the mobile phone;

[0027] The third switch unit (401) is used to select to send the first sound electrical signal to the mobile phone or the camera, so as to select to connect to the mobile phone or the camera.

[0028] In one embodiment, the audio output interface (40) further includes: a playback monitoring interface (404);

[0029] The playback monitoring interface (404) is connected to the camera interface (403) and the mobile phone interface (402);

[0030] The playback monitoring interface (404) is used to connect to headphones and output the second sound electrical signal input from the camera interface (403) or the mobile phone interface (402) to the headphones.

[0031] In one embodiment, the audio output interface (40) further includes: a second filtering circuit (405), a third filtering circuit (406) and a fourth filtering circuit (407);

[0032] The second filter circuit (405) is connected to the mobile phone interface (402), one end of the third filter circuit (406) is connected to the left channel end of the camera interface (403), and one end of the fourth filter circuit (407) is connected to the right channel end of the camera interface (403);

[0033] The second filtering circuit (405) is used to filter the first sound electrical signal transmitted to the mobile phone interface (402);

[0034] The third filtering circuit (406) is used to filter the first sound electrical signal transmitted to the camera interface (403);

[0035] The fourth filtering circuit (407) is used to filter the first sound electrical signal transmitted to the camera interface (403).

[0036] In one embodiment, the low-cut unit (302) includes: a first capacitor (C1) and a first resistor (R1), and the first switch unit (301) includes: a first switch (SW1);

[0037] One end of the first capacitor (C1) is connected to the first switch (SW1), and the other end of the first capacitor (C1) is grounded; one end of the first resistor (R1) is connected to the first switch (SW1), and the other end of the first resistor (R1) is grounded.

[0038] In one embodiment, the gain adjustment unit (501) includes: a second capacitor (C2), a second resistor (R2) and a third resistor (R3), and the second switch unit (502) includes: a second switch (SW2);

[0039] One end of the second resistor (R2) is connected to the output end of the sound collection interface (10), the other end of the second resistor (R2) is connected to one end of the second switch (SW2) and one end of the third resistor (R3), the other end of the third resistor (R3) is connected to the other end of the second switch (SW2) and one end of the second capacitor (C2), and the other end of the second capacitor (C2) is grounded.

[0040] In one embodiment, the third switch unit (401) comprises: a third switch (SW3);

[0041] The first filter circuit (20) comprises: a third capacitor (C3), a fourth capacitor (C4), a fourth resistor (R4) and a first Zener diode (D1);

[0042] One end of the first Zener diode (D1) is connected to the output end of the sound collection interface (10), and the other end of the first Zener diode (D1) is grounded; one end of the third capacitor (C3) is connected to the output end of the sound collection interface (10), and the other end of the third capacitor (C3) is grounded; one end of the fourth capacitor (C4) is connected to the output end of the sound collection interface (10), and the other end of the fourth capacitor (C4) is grounded; one end of the fourth resistor (R4) is connected to the output end of the sound collection interface (10), and the other end of the fourth resistor (R4) is grounded;

[0043] The second filtering circuit (405) comprises: a fifth capacitor (C5), a fifth resistor (R5), a sixth resistor (R6) and a second Zener diode (D2);

[0044] One end of the fifth resistor (R5) is connected to one end of the third switch (SW3) connected to the mobile phone interface (402), the other end of the fifth resistor (R5) is connected to the mobile phone interface (402), one end of the fifth capacitor (C5) is connected to the mobile phone interface (402), the other end of the fifth capacitor (C5) is grounded, one end of the sixth resistor (R6) is connected to the mobile phone interface (402), the other end of the sixth resistor (R6) is grounded, one end of the second Zener diode (D2) is connected to the mobile phone interface (402), and the other end of the second Zener diode (D2) is grounded;

[0045] The third filtering circuit (406) comprises: a sixth capacitor (C6), a seventh resistor (R7), an eighth resistor (R8) and a third Zener diode (D3);

[0046] One end of the seventh resistor (R7) is connected to the third switch (SW3), the other end of the seventh resistor (R7) is connected to the left channel port of the camera interface (403), one end of the sixth capacitor (C6) is connected to the left channel port of the camera interface (403), the other end of the sixth capacitor (C6) is grounded, one end of the eighth resistor (R8) is connected to the left channel port of the camera interface (403), the other end of the eighth resistor (R8) is grounded, one end of the third Zener diode (D3) is connected to the left channel port of the camera interface (403), and the other end of the third Zener diode (D3) is grounded;

[0047] The fourth filtering circuit (407) comprises: a seventh capacitor (C7), a ninth resistor (R9), a tenth resistor (R10) and a fourth Zener diode (D4);

[0048] One end of the ninth resistor (R9) is connected to the third switch (SW3), the other end of the ninth resistor (R9) is connected to the right channel port of the camera interface (403), one end of the seventh capacitor (C7) is connected to the right channel port of the camera interface (403), the other end of the seventh capacitor (C7) is grounded, one end of the tenth resistor (R10) is connected to the right channel port of the camera interface (403), the other end of the tenth resistor (R10) is grounded, one end of the fourth Zener diode (D4) is connected to the right channel port of the camera interface (403), and the other end of the fourth Zener diode (D4) is grounded.

[0049] The present invention provides a low-cut adjustable microphone system. Specifically, in the present application, the working process of the system is as follows: first, a sound collection interface (10) collects a first sound electrical signal, and at the same time receives the current fed back by an audio output interface (40) to power a sound collection device; the collected first sound electrical signal is transmitted to a first filter circuit (20) for processing; under the control of a low-cut circuit (30), the first filter circuit (20) can adjust the filter frequency according to actual needs and filter the components of a specific frequency in the first sound electrical signal; the processed signal is transmitted to an external device through an audio output interface (40); the entire system realizes real-time adjustable control of low-frequency noise by means of an analog circuit.

[0050] In the present application, since an analog circuit combination scheme of a sound collection interface (10), a first filter circuit (20), a low-cut circuit (30) and an audio output interface (40) is adopted, and a linkage control relationship is formed between the low-cut circuit (30) and the first filter circuit (20), the real-time adjustment of the filter frequency can be achieved without using a DSP chip, which effectively solves the problems of high cost, high power consumption and signal conversion delay of the traditional DSP scheme, thereby realizing a simple, economical, low-power and highly adaptable low-cut adjustment function. Specifically: first, the analog circuit scheme avoids the use of DSP chips, significantly reducing system cost and power consumption; second, the dynamic adjustment capability of the low-cut circuit (30) to the filter frequency of the first filter circuit (20) enables the system to flexibly adjust the filter parameters according to the low-frequency noise characteristics in different scenarios, thereby improving the adaptability of the system; this design not only simplifies the system structure and reduces the implementation cost, but also provides a more flexible low-frequency noise processing scheme, which can better meet the requirements of different recording scenarios for audio quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0052] Figure 1 A schematic diagram of a functional module structure provided for the first embodiment of the low-cut adjustable microphone system of the present application;

[0053] Figure 2 A schematic diagram of a functional module structure provided for the second embodiment of the low-cut adjustable microphone system of the present application;

[0054] Figure 3 and Figure 4 A schematic diagram of a functional module structure provided for the third embodiment of the low-cut adjustable microphone system of the present application;

[0055] Figure 5 A schematic diagram of a TRRS connector provided for the third embodiment of the low-cut adjustable microphone system of the present application;

[0056] Figure 6 Another schematic diagram of the functional module structure provided for the third embodiment of the low-cut adjustable microphone system of the present application;

[0057] Figure 7 and Figure 8 A circuit structure schematic diagram provided for the fourth embodiment of the low-cut adjustment microphone system of the present application.

[0058] Description of Figure Numbers:

[0059] Label name Label name 10 Sound collection interface 20 First filter circuit 30 Low-cut circuit 40 Audio output interface 50 Gain Adjustment Circuit 301 The first switch unit 302 Low-cut unit 401 The third switch unit 402 Mobile phone interface 403 Camera interface 404 Playback monitoring interface 405 Second filter circuit 406 The third filter circuit 407 Fourth filter circuit 501 Gain adjustment unit 502 The second switch unit

[0060] Label name Label name R1 First resistor R2 Second resistor R3 The third resistor R4 The fourth resistor R5 Fifth resistor R6 The sixth resistor R7 Seventh resistor R8 Eighth resistor R9 Ninth resistor R10 Tenth resistor R11 The eleventh resistor C1 First capacitor C2 Second capacitor C3 The third capacitor C4 The fourth capacitor C5 Fifth capacitor C6 Sixth capacitor C7 Seventh capacitor D1 First Zener diode D2 Second Zener diode D3 The third Zener diode D4 The fourth Zener diode SW1 First switch SW2 Second switch SW3 Third switch

[0061] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments. DETAILED DESCRIPTION

[0062] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0063] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, and back), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0064] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0065] This application proposes a schematic diagram of the structure of a low-cut adjustment microphone system of the first embodiment, please refer to Figure 1 , the low-cut adjustment microphone system includes: a sound collection interface 10, a first filter circuit 20, a low-cut circuit 30 and an audio output interface 40;

[0066] The sound collection interface 10 is connected to the first filter circuit 20 and the audio output interface 40, and the low-cut circuit 30 is connected to the first filter circuit 20;

[0067] Among them, the sound collection interface 10 refers to a circuit unit for collecting external sounds and generating audio signals. The first filter circuit 20 represents a circuit module for frequency selective filtering of audio signals, which can filter the input signal according to the set cutoff frequency. The low-cut circuit 30 refers to a control circuit for adjusting the cutoff frequency of the first filter circuit 20, and dynamically adjusts the filter frequency by changing the circuit parameters. The audio output interface 40 represents an interface circuit unit for connecting to an external device and transmitting audio signals, which can output the processed audio signal to the external device.

[0068] The sound collection interface 10 is used as the input end of the system, and is mainly used for sound collection and conversion, as follows:

[0069] First, in the sound collection stage: the built-in acoustic sensor senses the sound wave vibration in the air. This sound wave vibration contains various physical properties of the sound, such as frequency, amplitude and other information. The acoustic sensor can respond to these sound wave vibrations and initially convert the mechanical energy of the sound wave into a processable form.

[0070] Then in the signal conversion stage: the captured sound wave vibration is converted into an electrical signal, namely the first sound electrical signal. This conversion process converts the mechanical vibration energy of the sound wave into a corresponding voltage or current change. The converted first sound electrical signal maintains a corresponding relationship with the original sound signal in terms of amplitude and frequency, thereby ensuring the accurate conversion of sound information.

[0071] At the same time, optionally, the sound collection interface 10 can also obtain current through the audio output interface 40 to provide a stable working power supply for the sound collection interface 10 itself, thereby ensuring the normal operation of the sound collection interface 10.

[0072] The first filter circuit 20 is a core signal processing unit responsible for frequency selective filtering of the input first sound electrical signal. The circuit adopts a high-pass filter structure, which can effectively attenuate signal components below the cutoff frequency while keeping the effective audio signal above the cutoff frequency unaffected. Through this processing, low-frequency noise, such as air conditioning noise, wind noise and other environmental interference, can be effectively removed.

[0073] The low-cut circuit 30 works closely with the first filter circuit 20 to change its cutoff frequency by dynamically adjusting key parameters of the first filter circuit 20. This adjustment capability enables the system to flexibly set the most suitable filter frequency according to the noise characteristics in different scenarios, thereby achieving precise noise control.

[0074] The audio output interface 40 is the output end of the system and has a bidirectional signal transmission capability. On the one hand, it transmits the processed audio signal to the external device; on the other hand, it can receive the audio signal from the external device and power the sound collection device through current feedback.

[0075] The specific working process is as follows:

[0076] Signal collection stage: When the sound collection interface 10 collects the first sound electrical signal, the audio output interface 40 feeds back the current of the external device connected to the audio output interface 40 to the sound collection interface 10 through the internal circuit, forming a complete power supply loop to power the sound collection interface 10.

[0077] Signal shunting processing stage: The first sound electrical signal entering the system will enter the first filter circuit 20 for low-cut processing, as follows:

[0078] The first filter circuit 20 performs high-pass filtering on the signal according to the currently set cutoff frequency under the real-time control of the low-cut circuit 30. For example, when recording indoors, it may be necessary to filter air conditioning noise around 50 Hz, while outdoors it may be necessary to process traffic noise around 100 Hz. At this time, the low-cut circuit 30 will adjust the cutoff frequency of the first filter circuit 20 accordingly.

[0079] Signal output stage: The processed audio signal is transmitted to an external device through the audio output interface 40.

[0080] During the entire process, the system realizes real-time signal processing and dynamic parameter adjustment through analog circuits, which ensures the quality of signal processing while avoiding the delay caused by digital processing, and provides a flexible noise control solution for audio recording in different scenarios.

[0081] In some embodiments, the filtering function of the first filtering circuit 20 can be realized in a variety of ways: optionally, an RC high-pass filter design is adopted, a basic filtering unit is formed by a series combination of resistors and capacitors, and a multi-stage RC network is used to improve the filtering effect, and finally an operational amplifier is used to amplify the signal and match the impedance; optionally, an active filter design is adopted, an operational amplifier is used to construct a second-order or higher-order high-pass filter circuit, a steeper filtering characteristic is achieved through a feedback network, and a variable cutoff frequency is achieved through circuit parameter adjustment. It is understandable that other types of filtering circuits can also be used to realize the function of the first filtering circuit 20, which is not limited here.

[0082] In some embodiments, the adjustment function of the low-cut circuit 30 can be realized in a variety of ways: optionally, a digital potentiometer solution is adopted, and the potentiometer resistance is adjusted by a digital control signal to change the cutoff frequency of the filter circuit, and a multi-speed frequency preset function is realized by a microcontroller; optionally, an analog switch array solution is adopted, and the parameters of the filter circuit are changed by switching resistor networks with different resistance values, so as to realize a discrete frequency adjustment function, and an intuitive human-computer interaction interface is provided by a rotary encoder. It is understandable that other types of adjustment circuits can also be used to realize the function of the low-cut circuit 30, which is not limited here.

[0083] In some embodiments, the signal transmission function of the audio output interface 40 can be implemented in a variety of ways: optionally, a balanced output design is adopted, a balanced output stage is constructed by a differential amplifier, a signal transmission with high anti-interference capability is achieved, and electrical isolation protection is provided by an isolation transformer; optionally, an unbalanced output design is adopted, high-quality signal transmission is achieved by an impedance matching network and a buffer amplifier, and overvoltage and overcurrent are prevented by a protection circuit. It is understandable that other types of output interface circuits can also be used to implement the functions of the audio output interface 40, which are not limited here.

[0084] In general, in this embodiment, the working process of the system is as follows: first, the first sound electrical signal is collected through the sound collection interface 10 and input into the system, and the sound collection interface 10 simultaneously receives the current fed back by the audio output interface 40 to power the sound collection device; the input first sound electrical signal is transmitted to the first filter circuit 20 for processing; under the control of the low-cut circuit 30, the first filter circuit 20 can adjust the filter frequency according to actual needs and filter the specific frequency components in the first sound electrical signal; the processed signal is transmitted to the external device through the audio output interface 40, and the entire system realizes real-time adjustable control of low-frequency noise through analog circuits.

[0085] In this embodiment, since the analog circuit combination scheme of the sound collection interface 10, the first filter circuit 20, the low-cut circuit 30 and the audio output interface 40 is adopted, and the low-cut circuit 30 forms a linkage control relationship with the first filter circuit 20, the real-time adjustment of the filter frequency can be achieved without using a DSP chip, which effectively solves the problems of high cost, high power consumption and signal conversion delay of the traditional DSP scheme, thereby realizing a simple, economical, low-power and adaptable low-cut adjustment function. Specifically: first, the analog circuit scheme avoids the use of DSP chips, significantly reducing system costs and power consumption; secondly, the dynamic adjustment capability of the low-cut circuit 30 to the filter frequency of the first filter circuit 20 enables the system to flexibly adjust the filter parameters according to the low-frequency noise characteristics in different scenarios, thereby improving the adaptability of the system. This design not only simplifies the system structure and reduces the implementation cost, but also provides a more flexible low-frequency noise processing scheme, which can better meet the requirements of different recording scenarios for audio quality.

[0086] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as those in the above-mentioned embodiment 1 can refer to the above introduction, and will not be repeated later. Figure 2 Based on the first embodiment, this embodiment proposes a gain adjustment circuit 50 for adjusting the amplitude of the first sound electrical signal as follows:

[0087] The gain adjustment circuit 50 is connected to the output end of the sound collection interface 10;

[0088] Among them, the gain adjustment circuit 50 refers to a circuit module for controlling the amplitude of the audio signal. The circuit can amplify or attenuate the input audio signal according to actual needs, thereby adjusting the strength of the signal. The gain adjustment circuit 50 usually includes functional units such as a preamplifier, a signal conditioning circuit, and an output buffer. For example, the adjustable gain amplifier circuit commonly seen in professional audio equipment can adjust the signal gain through a knob or button to achieve a signal gain adjustment range of -20dB to +60dB. Gain adjustment includes voltage gain and power gain, where voltage gain is mainly used to increase the signal level, while power gain is used to drive the load.

[0089] The function of the gain adjustment circuit 50 is to adjust the amplitude of the audio signal from the sound collection interface 10 so that the signal reaches a suitable level range to adapt to different usage scenarios and subsequent processing requirements. Specifically, when the first sound electrical signal output by the sound collection interface 10 enters the gain adjustment circuit 50, it is firstly amplified by the preamplifier. This stage mainly considers the optimization of the signal-to-noise ratio; then the signal enters the adjustable gain stage, and the dynamic adjustment of the signal amplitude is achieved by changing the parameters of the feedback network; then, the adjusted signal is subjected to impedance matching and level adjustment at the output stage to ensure the quality and driving capability of the output signal. In practical applications, the gain adjustment circuit 50 can flexibly adjust the signal gain according to different recording scenarios and sound source characteristics. For example, when recording a weaker sound source, the gain can be increased to obtain a sufficient signal level; when recording a stronger sound source, the gain can be reduced to avoid signal distortion. The entire gain adjustment process needs to ensure that the dynamic range of the signal is reasonably utilized while avoiding the introduction of additional noise and distortion.

[0090] Based on the first and / or second embodiments of the present application, in the third embodiment of the present application, the same or similar contents as those in the first and second embodiments can be referred to the above description, and will not be repeated in detail. Based on the first and / or second embodiments, this embodiment further proposes a more specific structure of the low-cut circuit 30, the gain adjustment circuit 50 and the audio output interface 40, and refer to Figure 3 and Figure 4 as follows:

[0091] in Figure 3 and Figure 4 The OA1 ports are connected to each other;

[0092] The low-cut circuit 30 includes: a first switch unit 301 and a low-cut unit 302;

[0093] One end of the first switch unit 301 is connected to the first filter circuit 20, and the other end of the first switch SW1 is connected to the low-cut unit 302;

[0094] The first switch unit 301 refers to a switch device for controlling the on / off state of the circuit, and the unit can switch the circuit connection state according to the control signal, thereby controlling whether the low-cut unit 302 is connected to the first filter circuit 20. The first switch unit 301 generally includes functional components such as a switch body, a drive circuit, and a state indicator. For example, the electronic switch circuit commonly found in professional audio equipment can control the switch state through a key or remote control signal, achieve millisecond-level fast switching, and have a state memory function.

[0095] The low-cut unit 302 refers to a functional module for adjusting the cutoff frequency of the first filter circuit 20, and the unit can adjust the frequency response characteristics of the filter circuit by changing the key parameters of the filter circuit. The low-cut unit 302 usually includes functional components such as a variable resistor network and a parameter adjustment circuit. For example, a low-cut control circuit commonly used in professional audio systems can achieve continuous cutoff frequency adjustment in the range of 20Hz to 400Hz, and has a preset frequency point fast switching function.

[0096] The function of the first switch unit 301 is to control the connection state between the low-cut unit 302 and the first filter circuit 20, so as to enable or disable the low-cut function. The function of the low-cut unit 302 is to change the cutoff frequency of the first filter circuit 20 by adjusting the parameters thereof, so as to achieve selective filtering of noises of different frequencies. Specifically, when the low-cut function needs to be enabled, the first switch unit 301 is closed by a control signal or manual operation, and a connection path between the low-cut unit 302 and the first filter circuit 20 is established. At this time, the low-cut unit 302 can effectively adjust the cutoff frequency of the first filter circuit 20; when the low-cut function needs to be disabled, the first switch unit 301 is disconnected by a control signal or manual operation, and the connection between the low-cut unit 302 and the first filter circuit 20 is cut off. At this time, the first filter circuit 20 will maintain its default frequency characteristics. In practical applications, this control method can flexibly adjust the filter characteristics according to different recording environments. For example, a lower cutoff frequency may be required to retain more low-frequency information when recording indoors, while a higher cutoff frequency may be required to suppress environmental noise when recording outdoors. The entire adjustment process needs to ensure that the switch action is reliable and avoid unnecessary noise interference during the switching process.

[0097] In some embodiments, the control function of the first switch unit 301 can be implemented in a variety of ways: optionally, a mechanical relay solution is adopted, firstly, the relay coil is driven by a control signal to generate electromagnetic force, then the circuit is physically disconnected by a mechanical contact, and finally the electromagnetic interference in the switching process is suppressed by a demagnetization circuit, and a protection circuit is added at both ends of the contact to extend the service life; optionally, a solid-state relay solution is adopted, the electrical isolation of the control signal is achieved by an optical coupler, and then the signal path is controlled by a MOSFET switch tube, and finally a stable gate voltage is provided by a drive circuit, and overvoltage protection and status detection functions are integrated. It is understandable that other types of switch circuits can also be used to implement the control function of the first switch unit 301, which is not limited here.

[0098] In some embodiments, the frequency adjustment function of the low-cut unit 302 can be implemented in a variety of ways: optionally, a variable resistor network solution is adopted, firstly an RC filter network is constructed through a digital potentiometer, then the potentiometer resistance is controlled through a serial interface to change the time constant, and finally the adjusted control signal is output through an operational amplifier buffer; optionally, a switched capacitor filter solution is adopted, a sampling clock is generated through a programmable clock generator, and then the frequency adjustment is achieved through a switched capacitor array, and finally a continuous time signal is output through a reconstruction filter, and a multi-stage filtering selection function is provided. It is understandable that other types of parameter adjustment circuits can also be used to implement the frequency adjustment function of the low-cut unit 302, which is not limited here.

[0099] The gain adjustment circuit 50 includes: a second switch unit 502 and a gain adjustment unit 501;

[0100] The second switch unit 502 is connected to the gain adjustment unit 501, and the gain adjustment unit 501 is connected to the output end of the sound collection interface 10;

[0101] The second switch unit 502 is a switch device for controlling the gain setting value, which can change the working parameters of the gain adjustment unit 501 according to user operation or automatic control signals. The second switch unit 502 may include functional components such as a multi-position switch, an encoder or a digital control interface.

[0102] The gain adjustment unit 501 refers to a functional module for actually performing signal amplitude adjustment, and the unit can amplify or attenuate the input audio signal according to the gain value set by the second switch unit 502. The gain adjustment unit 501 generally includes functional components such as a variable gain amplifier, a signal conditioning circuit, and an output buffer. For example, a programmable gain amplifier commonly used in professional recording equipment can achieve precise gain control within a range of -20dB to +60dB and has an overload protection function.

[0103] The function of the second switch unit 502 is to provide a gain control signal, and the function of the gain adjustment unit 501 is to perform actual signal amplification. Specifically, when the first sound electrical signal output by the sound collection interface 10 enters the gain adjustment unit 501, the user can adjust the internal structure of the second switch unit 502 according to the gain multiple required for adjustment, and then change the internal structure of the gain adjustment unit 501 to change the gain multiple, so as to achieve precise control of the signal amplitude of the first electrical signal. In practical applications, this gain control method can adapt to different recording scene requirements. For example, when recording a weaker sound source, a larger gain value can be selected through the second switch unit 502, and when recording a stronger sound source, a smaller gain value can be selected, so as to always maintain an appropriate output level. The entire adjustment process needs to ensure the smoothness of the gain switching to avoid popping or distortion.

[0104] The audio output interface 40 includes: a second filter circuit 405, a third filter circuit 406, a fourth filter circuit 407, a third switch unit 401, a camera interface 403 and a mobile phone interface 402;

[0105] The third switch unit 401 is a multi-channel audio signal switching device for controlling the routing and distribution of audio signals between different interfaces. It can realize the directional transmission of microphone acquisition signals to mobile phones or cameras, and the transmission control of device return signals to playback devices. In practical applications, it can be operated and controlled by physical buttons or knobs.

[0106] The second, third and fourth filter circuits 407 are processing circuits for signal purification and optimization. The second filter circuit 405 is specifically responsible for processing the signal of the mobile phone channel, and the third and fourth filter circuits 407 are responsible for processing the left and right channel signals of the camera interface 403 respectively. These filter circuits can use a combination of high-pass, low-pass or band-pass filters to achieve specific frequency response characteristics.

[0107] Specifically, in the signal output link, when the user accesses the output target device, the third switch unit 401 can be operated to implement different signal processing paths:

[0108] If a mobile phone is selected as the output device, the first sound electrical signal collected by the sound collection device will be processed by the second filter circuit 405. The circuit will optimize the signal according to the characteristics of the mobile phone device, including removing power frequency interference, optimizing frequency response, etc. The processed first sound electrical signal is output from the mobile phone interface 402 to the connected mobile phone.

[0109] If the camera is selected as the output device, the system will divide the signal into left and right channels: the left channel signal is processed by the third filter circuit 406, and the right channel signal is processed by the fourth filter circuit 407. These two filter circuits will perform special signal conditioning according to the audio input characteristics of the camera, including optimizing the frequency response characteristics and eliminating crosstalk, etc. The processed first sound electrical signal is output from the camera interface 403.

[0110] In addition, in this embodiment, the system can also realize the playback monitoring function, refer to Figure 6 :

[0111] The audio output interface 40 further includes: a playback monitoring interface 404;

[0112] The playback monitoring interface 404 is connected to the camera interface 403 and the mobile phone interface 402 and is used to connect a sound playing device (such as headphones).

[0113] In actual use, when the user needs to monitor the playback of recorded audio or video, the third switch unit 401 can be operated to implement the playback monitoring function. At this time, the second sound electrical signal (i.e., playback signal) played by the mobile phone or camera will be output to the connected sound playback device such as headphones through the playback monitoring interface 404. For the signal played back by the camera, the left and right channels will be processed by the third filter circuit 406 and the fourth filter circuit 407 respectively, and then transmitted to the playback monitoring interface 404; while the signal played back by the mobile phone will be processed by the second filter circuit 405 and then transmitted to the playback monitoring interface 404.

[0114] In some embodiments, the functions of the second filtering circuit 405, the third filtering circuit 406 and the fourth filtering circuit 407 can be implemented in a variety of ways:

[0115] Optionally, an analog filtering solution is adopted, firstly, a basic filtering unit is constructed using an RC network to set the cutoff frequency, then an active filtering circuit is constructed through an operational amplifier to adjust the gain and Q value, and finally multiple filtering units are cascaded to achieve a steeper frequency response characteristic; Optionally, a switched capacitor filter solution is adopted, firstly a sampling clock is generated through a clock control circuit, then a programmable filtering characteristic is realized using the switched capacitor principle, and finally the signal is reconstructed and amplified through an operational amplifier. It is understandable that other types of filtering circuits can also be used to realize the frequency selection function of the signal, which is not limited here.

[0116] In some embodiments, the function of the third switch unit 401 can be implemented in multiple ways:

[0117] Optionally, a mechanical switch solution is adopted, firstly a multi-way rotary switch structure is designed to realize signal path selection, then reliable contact is ensured by spring contacts, and finally metal contacts are used to ensure signal quality; Optionally, an electronic switch solution is adopted, firstly an analog switch chip is used to build a signal switching matrix, then a microcontroller is used to read user input and control the switch state, and finally an LED is used to indicate the currently selected channel. It is understandable that other switch solutions can also be used to realize the signal routing selection function, which is not limited here.

[0118] In some embodiments, the functions of the camera interface 403 and the mobile phone interface 402 can be implemented in a variety of ways:

[0119] Optional, reference Figure 4 and Figure 5 , using a four-section TRRS audio wiring solution, where Figure 5 This is the structure diagram of the TRRS connector:

[0120] First, four welding points, L (left channel), R (right channel), AOUT (audio output), and GND (ground), are set on the circuit board; then the L (left channel) and R (right channel) ends of the camera interface 403, as well as the AOUT (audio output) and GND (ground) ends of the mobile phone interface 402, are respectively welded to the corresponding welding points through the four wires of the four-core shielded audio cable to ensure that the welding is firm and to avoid short circuits; then a standard 3.5mm four-section TRRS male plug is installed at the other end of the audio cable, and each wire is connected according to the TRRS standard definition; finally, the shielding layer is grounded and strain protection is performed to ensure connection reliability. In this way, the four interfaces can realize the transmission of microphone signals to the camera and mobile phone through the four-section TRRS male plug, and also support the monitoring function of the device playback signal, ensuring the two-way transmission requirements of the audio system.

[0121] It is understandable that other interface implementation schemes may also be used to complete the input and output functions of audio signals, including but not limited to using other types of audio interfaces or digital interfaces, which are not limited here.

[0122] Based on the first embodiment and / or the second embodiment and / or the third embodiment of the present application, in the fourth embodiment of the present application, the same or similar contents as those in the above-mentioned first embodiment, second embodiment and third embodiment can refer to the above introduction, and will not be repeated later. This embodiment proposes a specific circuit structure of the low-cut adjustment microphone system, and reference is made to Figure 5 and Figure 6 ,as follows:

[0123] in Figure 7 and Figure 8 The OA2 ports are connected to each other;

[0124] The low-cut unit 302 includes: a first capacitor C1 and a first resistor R1, and the first switch unit 301 includes: a first switch SW1;

[0125] One end of the first capacitor C1 is connected to the first switch SW1 , and the other end of the first capacitor C1 is grounded. One end of the first resistor R1 is connected to the first switch SW1 , and the other end of the first resistor R1 is grounded.

[0126] The gain adjustment unit 501 includes: a second capacitor C2, a second resistor R2 and a third resistor R3, and the second switch unit 502 includes: a second switch SW2;

[0127] One end of the second resistor R2 is connected to the output end of the sound collection interface 10, the other end of the second resistor R2 is connected to one end of the second switch SW2 and one end of the third resistor R3, the other end of the third resistor R3 is connected to the other end of the second switch SW2 and one end of the second capacitor C2, and the other end of the second capacitor C2 is grounded.

[0128] One end of the first capacitor C1 is connected to the first switch SW1 , and the other end of the first capacitor C1 is grounded. One end of the first resistor R1 is connected to the first switch SW1 , and the other end of the first resistor R1 is grounded.

[0129] The third switch unit 401 includes: a third switch SW3;

[0130] The first filter circuit 20 includes: a third capacitor C3, a fourth capacitor C4, a fourth resistor R4 and a first Zener diode D1;

[0131] One end of the first Zener diode D1 is connected to the output end of the sound collection interface 10, and the other end of the first Zener diode D1 is grounded; one end of the third capacitor C3 is connected to the output end of the sound collection interface 10, and the other end of the third capacitor C3 is grounded; one end of the fourth capacitor C4 is connected to the output end of the sound collection interface 10, and the other end of the fourth capacitor C4 is grounded; one end of the fourth resistor R4 is connected to the output end of the sound collection interface 10, and the other end of the fourth resistor R4 is grounded;

[0132] The second filter circuit 405 includes: a fifth capacitor C5, a fifth resistor R5, a sixth resistor R6 and a second Zener diode D2;

[0133] One end of the fifth resistor R5 is connected to one end of the third switch SW3 connected to the mobile phone interface 402, the other end of the fifth resistor R5 is connected to the mobile phone interface 402, one end of the fifth capacitor C5 is connected to the mobile phone interface 402, the other end of the fifth capacitor C5 is grounded, one end of the sixth resistor R6 is connected to the mobile phone interface 402, the other end of the sixth resistor R6 is grounded, one end of the second Zener diode D2 is connected to the mobile phone interface 402, and the other end of the second Zener diode D2 is grounded;

[0134] The third filtering circuit 406 includes: a sixth capacitor C6, a seventh resistor R7, an eighth resistor R8 and a third Zener diode D3;

[0135] One end of the seventh resistor R7 is connected to the third switch SW3, and the other end of the seventh resistor R7 is connected to the left channel port of the camera interface 403. One end of the sixth capacitor C6 is connected to the left channel port of the camera interface 403, and the other end of the sixth capacitor C6 is grounded. One end of the eighth resistor R8 is connected to the left channel port of the camera interface 403, and the other end of the eighth resistor R8 is grounded. One end of the third Zener diode D3 is connected to the left channel port of the camera interface 403, and the other end of the third Zener diode D3 is grounded.

[0136] The fourth filtering circuit 407 includes: a seventh capacitor C7, a ninth resistor R9, a tenth resistor R10 and a fourth Zener diode D4;

[0137] One end of the ninth resistor R9 is connected to the third switch SW3, and the other end of the ninth resistor R9 is connected to the right channel port of the camera interface 403, one end of the seventh capacitor C7 is connected to the right channel port of the camera interface 403, and the other end of the seventh capacitor C7 is grounded, one end of the tenth resistor R10 is connected to the right channel port of the camera interface 403, and the other end of the tenth resistor R10 is grounded, one end of the fourth Zener diode D4 is connected to the right channel port of the camera interface 403, and the other end of the fourth Zener diode D4 is grounded.

[0138] (1) Realization of low-cut function: The DC bias voltage required by the sound collection device is provided by the externally connected device (camera or mobile phone, etc.) in the figure after current limiting through the eleventh resistor R11.

[0139] The first sound electrical signal formed by the sound collection interface 10 is composed of two parts: DC (bias voltage) and AC (AC voltage signal converted by the condenser microphone). If the toggle switch is not connected to the circuit, the DC bias circuit is composed of the eleventh resistor R11, the DC equivalent resistor of the sound collection device (about 2.2K) and the fourth resistor R4 in series. The bias voltage of the sound collection device is V c , V c =[R mic / (R4+R11+R mic )]·V cc (bias voltage), where R mic= is the equivalent DC resistance of the sound collection device. Since the capacitor has the characteristics of passing AC and blocking DC, the MIC- terminal is grounded through capacitors C3 and C4. Therefore, for AC signals, MIC- is equivalent to direct grounding. The AC signal part of the first sound electrical signal generated by the sound collection device can only be transmitted to the subsequent equipment from MIC+ and R11; MIC- is connected to the ground in parallel through R4, C3, and C4. The RC parallel resonant circuit composed of R4, C3, and C4 has a frequency selection characteristic. The frequency selection frequency F o Determined by the resistance value of R4 and the capacitance values ​​of C3 and C4, Fo=1 / [2π·R4·(C3+C4)]. The frequency response switching circuit is composed of the toggle switch SW1, the resistor R1, and the capacitor C3. When SW1 is switched to the 2-3 / 5-6 connection state, there are no resistance and capacitance components, and there is no change in the resistance and capacitance in the loop, which has no effect on the frequency response. Its resonant frequency is F o =1 / [2π·R4·(C3+C4)]; Due to the high sensitivity of the capacitor (electret) of the sound collection equipment, it is easy to record low-frequency noise in the environmental noise during use, such as wind noise or interference noise emitted by industrial control equipment when working, which affects the clarity and restoration of the human voice; when the 1-2 / 4-5 of the toggle switch SW1 is turned on, the parallel circuit composed of resistor R1 and capacitor C3 is connected to the MIC-end, and the resistance and capacitance of the MIC-end change accordingly: the total resistance R=R1 / / R4=R1·R4 / R1+R4, the total resistance in the circuit must be less than any resistance of R1 and R4; the total capacitance C in the circuit=C1+C3+C4, the main function of C1 is to reduce the interference noise when R1 and SW2 are connected to the circuit, and the value should be far Any capacitor value less than C3 or C4 can be ignored relative to C3 and C4. After R1 and C1 are connected to the circuit, their resonant frequency Fo=1 / 2π·R·C. The appropriate Fo can be set by reasonably setting the values ​​of R1, R4, C1, C2, and C3. From the circuit, it can be seen that the connection of R1 and C1 only changes the resistance and capacitance between the MIC-end and the ground end, and has no effect on the AC path (for AC signals, C1, C2, and C3 are equivalent to short circuits, that is, the MIC-end is equivalent to grounding). Therefore, the connection of R1 and C1 to the MIC-end will only affect F0. The frequency characteristics of the sound collection device at and below the frequency point of F0=1 / 2Π*R*C will be used to attenuate or filter the low-frequency part of the audio, which is the low-cut function.

[0140] (2) Implementation of gain adjustment: composed of a toggle switch SW2, resistors R2, R3 and capacitor C2; using the AC impedance characteristics of resistor R2 and capacitor C2 to audio, the audio signal amplitude (sound electrical signal) is attenuated to achieve two-level gain adjustment; when 2-3 and 5-6 of SW2 are connected, resistors R2 and R3 are connected in series and then form a series resonance with capacitor C4, where the resistance value of R3 is much larger than the resistance value of R2. Due to the isolation effect of the large resistance R3 on the AC audio signal of the first sound electrical signal, C2 has limited coupling to the ground of the AC audio signal of the first sound electrical signal, and basically no attenuation occurs, achieving a gain adjustment of 0dB; when 1-2 and 4-5 of the toggle switch SW2 are connected, the impedance generated by the series resonance circuit composed of R2 and C2 is small, and the AC audio signal of the first sound electrical signal is greatly attenuated, achieving a -10dB gain adjustment, and changing the values ​​of resistors R2, R3 and capacitor C2 at the same time can achieve different adjustment effects.

[0141] (3) Implementation of audio output: Audio switching is mainly completed by the double-linked toggle switch SW3. Depending on whether the device that outputs the first sound electrical signal is a mobile phone or a camera, it can be completed through the third switch SW3; when SW3 is turned to 2-3, 5-6, the first sound electrical signal is output to the mobile phone for recording. If SW3 is turned to 1-2, 4-5, the first sound electrical signal is divided into two paths and connected to the L and R ends of the camera for input to the camera for stereo dual-track recording; if SW3 is turned to 1-2, 4-5 when the recorded audio or video is played back, the playback monitoring function can be realized in the above position, that is, the second sound electrical signal of the mobile phone or camera is output to the headphones for playback through the playback monitoring interface 404.

[0142] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A low-cut adjustable microphone system, characterized in that: The low-cut adjustment microphone system comprises: a sound collection interface (10), a first filter circuit (20), a low-cut circuit (30) and an audio output interface (40); The sound collection interface (10) is connected to the first filter circuit (20) and the audio output interface (40), and the low-cut circuit (30) is connected to the first filter circuit (20); The sound collection interface (10) is used to collect a first sound electrical signal and transmit the first sound electrical signal to the first filter circuit; The low-cut circuit (30) is used to adjust the filtering frequency of the first filtering circuit (20); The first filtering circuit (20) is used to filter the first sound electrical signal at a currently set frequency, and send the filtered first sound electrical signal to the audio output interface (40); The audio output interface (40) is used to send the first sound electrical signal after filtering to an external device.

2. The low-cut adjustable microphone system according to claim 1, characterized in that The low-cut adjustment microphone system further comprises: a gain adjustment circuit (50); The gain adjustment circuit (50) is connected to the output end of the sound collection interface (10); The gain adjustment circuit (50) is used to adjust the signal amplitude of the first sound electrical signal.

3. The low-cut adjustable microphone system according to claim 1, characterized in that The low-cut circuit (30) comprises: a first switch unit (301) and a low-cut unit (302); One end of the first switch unit (301) is connected to the first filter circuit (20), and the other end of the first switch (SW1) is connected to the low-cut unit (302); The low-cut unit (302) is used to adjust the filtering frequency of the first filtering circuit (20); The first switch unit (301) is used to control the connection between the low-cut unit (302) and the first filter circuit (20).

4. The low-cut adjustable microphone system according to claim 2, characterized in that The gain adjustment circuit (50) comprises: a second switch unit (502) and a gain adjustment unit (501); The second switch unit (502) is connected to the gain adjustment unit (501), and the gain adjustment unit (501) is connected to the output end of the sound collection interface (10); The second switch unit (502) is used to adjust the gain of the gain adjustment unit (501); The gain adjustment unit (501) is used to adjust the signal amplitude of the first sound electrical signal according to the currently set gain.

5. The low-cut adjustable microphone system according to claim 1, characterized in that: The audio output interface (40) comprises: a third switch unit (401), a mobile phone interface (402) and a camera interface (403); One end of the third switch unit (401) is connected to the output end of the sound collection interface (10), and the other end of the third switch unit (401) is connected to the mobile phone interface (402) and the camera interface (403); The camera interface (403) is used to connect to a camera and transmit the first sound electrical signal to the camera; The mobile phone interface (402) is used to connect to a mobile phone and transmit the first sound electrical signal to the mobile phone; The third switch unit (401) is used to select to send the first sound electrical signal to the mobile phone or the camera, so as to select to connect to the mobile phone or the camera.

6. The low-cut adjustable microphone system according to claim 5, characterized in that The audio output interface (40) further includes: a playback monitoring interface (404); The playback monitoring interface (404) is connected to the camera interface (403) and the mobile phone interface (402); The playback monitoring interface (404) is used to connect to headphones and output the second sound electrical signal input from the camera interface (403) or the mobile phone interface (402) to the headphones.

7. The low-cut adjustable microphone system according to claim 5, characterized in that: The audio output interface (40) further comprises: a second filtering circuit (405), a third filtering circuit (406) and a fourth filtering circuit (407); The second filter circuit (405) is connected to the mobile phone interface (402), one end of the third filter circuit (406) is connected to the left channel end of the camera interface (403), and one end of the fourth filter circuit (407) is connected to the right channel end of the camera interface (403); The second filtering circuit (405) is used to filter the first sound electrical signal transmitted to the mobile phone interface (402); The third filtering circuit (406) is used to filter the first sound electrical signal transmitted to the camera interface (403); The fourth filtering circuit (407) is used to filter the first sound electrical signal transmitted to the camera interface (403).

8. The low-cut adjustable microphone system according to claim 3, characterized in that: The low-cut unit (302) comprises: a first capacitor (C1) and a first resistor (R1); the first switch unit (301) comprises: a first switch (SW1); One end of the first capacitor (C1) is connected to the first switch (SW1), and the other end of the first capacitor (C1) is grounded; one end of the first resistor (R1) is connected to the first switch (SW1), and the other end of the first resistor (R1) is grounded.

9. The low-cut adjustable microphone system according to claim 4, characterized in that: The gain adjustment unit (501) comprises: a second capacitor (C2), a second resistor (R2) and a third resistor (R3); the second switch unit (502) comprises: a second switch (SW2); One end of the second resistor (R2) is connected to the output end of the sound collection interface (10), the other end of the second resistor (R2) is connected to one end of the second switch (SW2) and one end of the third resistor (R3), the other end of the third resistor (R3) is connected to the other end of the second switch (SW2) and one end of the second capacitor (C2), and the other end of the second capacitor (C2) is grounded.

10. The low-cut adjustable microphone system according to claim 7, characterized in that: The third switch unit (401) comprises: a third switch (SW3); The first filter circuit (20) comprises: a third capacitor (C3), a fourth capacitor (C4), a fourth resistor (R4) and a first Zener diode (D1); One end of the first Zener diode (D1) is connected to the output end of the sound collection interface (10), and the other end of the first Zener diode (D1) is grounded; one end of the third capacitor (C3) is connected to the output end of the sound collection interface (10), and the other end of the third capacitor (C3) is grounded; one end of the fourth capacitor (C4) is connected to the output end of the sound collection interface (10), and the other end of the fourth capacitor (C4) is grounded; one end of the fourth resistor (R4) is connected to the output end of the sound collection interface (10), and the other end of the fourth resistor (R4) is grounded; The second filtering circuit (405) comprises: a fifth capacitor (C5), a fifth resistor (R5), a sixth resistor (R6) and a second Zener diode (D2); One end of the fifth resistor (R5) is connected to one end of the third switch (SW3) connected to the mobile phone interface (402), the other end of the fifth resistor (R5) is connected to the mobile phone interface (402), one end of the fifth capacitor (C5) is connected to the mobile phone interface (402), the other end of the fifth capacitor (C5) is grounded, one end of the sixth resistor (R6) is connected to the mobile phone interface (402), the other end of the sixth resistor (R6) is grounded, one end of the second Zener diode (D2) is connected to the mobile phone interface (402), and the other end of the second Zener diode (D2) is grounded; The third filtering circuit (406) comprises: a sixth capacitor (C6), a seventh resistor (R7), an eighth resistor (R8) and a third Zener diode (D3); One end of the seventh resistor (R7) is connected to the third switch (SW3), the other end of the seventh resistor (R7) is connected to the left channel port of the camera interface (403), one end of the sixth capacitor (C6) is connected to the left channel port of the camera interface (403), the other end of the sixth capacitor (C6) is grounded, one end of the eighth resistor (R8) is connected to the left channel port of the camera interface (403), the other end of the eighth resistor (R8) is grounded, one end of the third Zener diode (D3) is connected to the left channel port of the camera interface (403), and the other end of the third Zener diode (D3) is grounded; The fourth filtering circuit (407) comprises: a seventh capacitor (C7), a ninth resistor (R9), a tenth resistor (R10) and a fourth Zener diode (D4); One end of the ninth resistor (R9) is connected to the third switch (SW3), the other end of the ninth resistor (R9) is connected to the right channel port of the camera interface (403), one end of the seventh capacitor (C7) is connected to the right channel port of the camera interface (403), the other end of the seventh capacitor (C7) is grounded, one end of the tenth resistor (R10) is connected to the right channel port of the camera interface (403), the other end of the tenth resistor (R10) is grounded, one end of the fourth Zener diode (D4) is connected to the right channel port of the camera interface (403), and the other end of the fourth Zener diode (D4) is grounded.

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