Filter circuit with adjustable bass component

Abstract

The utility model discloses a filter circuit with an adjustable bass component. The filter circuit comprises a voltage-dividing filter circuit, an amplifying circuit and an active filter circuit, the first end of the voltage-dividing filter circuit is connected with an audio signal, the second end is connected with the first input end of the amplifying circuit, and the third end is connected with the second input end of the amplifying circuit; the voltage division filter circuit outputs a first voltage to the first input end of the amplification circuit and outputs a second voltage to the second input end of the amplification circuit. When a trigger instruction is received, the voltage value of the first voltage and the voltage value of the second voltage are adjusted according to the trigger instruction; the amplifying circuit amplifies the differential signal of the input end and outputs the amplified differential signal; and the active filter circuit filters signal components in a preset frequency range and outputs the filtered signal to a load. Due to the fact that the high-frequency component in the first voltage is filtered out, the ratio of the first voltage value to the second voltage value is changed through the voltage dividing and filtering circuit, the amplification degree of the amplifying circuit to the bass signal is changed, and bass adjustment is achieved.

Description

Technical Field

[0001] This utility model relates to the field of audio technology, and in particular to a bass component adjustable filter circuit. Background Technology

[0002] Ordinary full-range speakers have a monotonous tone and a muddy sound. A common solution is to add tweeters and woofers, using crossover to produce independent sound. However, analog audio links typically use fixed passive filtering circuits. But current technology suffers from limitations such as non-adjustable audio components and poor filtering performance. Utility Model Content

[0003] The main purpose of this invention is to provide a bass component adjustable filter circuit, which aims to achieve audio component adjustment and optimize the filtering effect.

[0004] To achieve the above objectives, the bass component adjustable filter circuit proposed in this utility model includes:

[0005] Voltage divider filter circuit, amplifier circuit and active filter circuit;

[0006] The first terminal of the voltage divider filter circuit is connected to the audio signal, the second terminal is connected to the first input terminal of the amplifier circuit, and the third terminal is connected to the second input terminal of the amplifier circuit; the output terminal and the second input terminal of the amplifier circuit are connected to each other, and the output terminal of the amplifier circuit is connected to the input terminal of the active filter circuit.

[0007] The voltage divider filter circuit is used to divide the audio signal, output a first voltage that filters out high-frequency components to the first input terminal of the amplifier circuit, and also output a second voltage to the second input terminal of the amplifier circuit.

[0008] The voltage divider filter circuit is also used to adjust the voltage values ​​of the first voltage and the second voltage according to the trigger command when a trigger command is received, thereby changing the ratio of the first voltage value to the second voltage value.

[0009] The amplifier circuit is used to amplify the difference between the first voltage value and the second voltage value and output it to the active filter circuit;

[0010] The active filter circuit is used to filter out signal components within a preset frequency range of the amplifier circuit output signal and output the filtered signal to the load.

[0011] This utility model discloses a bass component adjustable filter circuit, which includes: a voltage divider filter circuit, an amplifier circuit, and an active filter circuit; the first terminal of the voltage divider filter circuit is connected to an audio signal, the second terminal is connected to the first input terminal of the amplifier circuit, and the third terminal is connected to the second input terminal of the amplifier circuit; the output terminal and the second input terminal of the amplifier circuit are interconnected, and the output terminal of the amplifier circuit is connected to the input terminal of the active filter circuit; the voltage divider filter circuit is used to divide the audio signal, outputting a first voltage to the first input terminal of the amplifier circuit to filter out high-frequency components, and also outputting a second voltage to the second input terminal of the amplifier circuit; the voltage divider filter circuit is also used to adjust the voltage values ​​of the first voltage and the second voltage according to the trigger command when a trigger command is received, changing the ratio of the first voltage value to the second voltage value; the amplifier circuit is used to amplify the difference between the first voltage value and the second voltage value and output it to the active filter circuit; the active filter circuit is used to filter out signal components within a preset frequency range of the output signal of the amplifier circuit and output the filtered signal to the load. Since the high-frequency components in the first voltage are filtered out, this invention changes the ratio of the first voltage value to the second voltage value through a voltage divider filter circuit, thereby changing the amplification degree of the bass signal by the amplifier circuit and achieving bass adjustment. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of an embodiment of the adjustable bass component filter circuit of this utility model;

[0014] Figure 2 This is a schematic diagram of another embodiment of the adjustable bass component filter circuit of this utility model;

[0015] Figure 3 This is a schematic diagram of another embodiment of the adjustable bass component filter circuit of this utility model.

[0016] Figure 4 This is a schematic diagram of another embodiment of the adjustable bass component filter circuit of this utility model;

[0017] Figure 5 This is a schematic diagram of another embodiment of the adjustable bass component filter circuit of this utility model;

[0018] Figure 6 This is a schematic diagram of another embodiment of the adjustable bass component filter circuit of this utility model;

[0019] Figure 7 This is a schematic diagram of another embodiment of the adjustable bass component filter circuit of this utility model.

[0020] Explanation of icon numbers:

[0021]

[0022] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0025] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0026] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0027] This utility model proposes a bass component adjustable filter circuit, referring to... Figure 1 As shown, the adjustable bass component filter circuit includes:

[0028] Voltage divider filter circuit 10, amplifier circuit 20 and active filter circuit 30;

[0029] The first terminal of the voltage divider filter circuit 10 is connected to the audio signal, the second terminal is connected to the first input terminal of the amplifier circuit 20, and the third terminal is connected to the second input terminal of the amplifier circuit 20; the output terminal and the second input terminal of the amplifier circuit 20 are connected to each other, and the output terminal of the amplifier circuit 20 is connected to the input terminal of the active filter circuit 30.

[0030] The voltage divider filter circuit 10 is used to divide the audio signal, output a first voltage that filters out high-frequency components to the first input terminal of the amplifier circuit 20, and also output a second voltage to the second input terminal of the amplifier circuit 20.

[0031] The voltage divider filter circuit 10 is also used to adjust the voltage value of the first voltage and the voltage value of the second voltage according to the trigger command when a trigger command is received, thereby changing the ratio of the first voltage value to the second voltage value.

[0032] The amplifier circuit 20 is used to amplify the difference between the first voltage value and the second voltage value and output it to the active filter circuit 30;

[0033] The active filter circuit 30 is used to filter out signal components within a preset frequency range of the output signal of the amplifier circuit 20, and output the filtered signal to the load.

[0034] It should be noted that, in order to adjust the bass component, this solution uses a voltage divider filter circuit 10 to divide the input audio signal, outputting a first voltage to the positive input terminal of the amplifier circuit 20 and a second voltage to the negative input terminal of the amplifier circuit 20. The high-frequency component in the first voltage is filtered out. It should be pointed out that the characteristic frequency of the voltage divider filter circuit 10 in filtering the first voltage can be determined by the researchers, and the parameters in the voltage divider filter circuit 10 can be modified accordingly to achieve the characteristic frequency.

[0035] The amplifier circuit 20 amplifies the difference between the first voltage value and the second voltage value and outputs it to the active filter circuit 30 for filtering. The amplifier circuit 20 may include a first operational amplifier U1, the non-inverting input of the first operational amplifier U1 is connected to the second terminal of the voltage divider filter circuit 10, the inverting input is connected to the third terminal of the voltage divider filter circuit 10, and the output is connected to the active filter circuit 30. The output of the first operational amplifier U1 is connected to its inverting input.

[0036] The voltage divider filter circuit 10 is also used to adjust the voltage values ​​of the first voltage and the second voltage according to the trigger command when a trigger command is received. It should be noted that since the first voltage at the positive input terminal of the amplifier circuit 20 has high-frequency components filtered out, when the ratio of the first voltage value to the second voltage value changes, the signal strength at the second input terminal of the amplifier circuit 20 changes compared to the signal strength at the first input terminal, thereby affecting the amplification degree of the bass signal by the amplifier circuit 20, and thus adjusting the bass filtering variation.

[0037] The following example uses the amplifier circuit 20, which includes an operational amplifier. The operational amplifier strives to keep the voltages at the non-inverting and inverting input terminals equal, maintaining a "virtual short" state. In this circuit, a first voltage is connected to the non-inverting input terminal, and a second voltage is connected to the inverting input terminal. The first voltage filters out high-frequency components, so it mainly contains relatively low-frequency audio components; while the second voltage contains high-frequency components, with a relatively weaker low-frequency component. If the ratio of the first voltage value to the second voltage value is large, it means that the first voltage value is much higher than the second voltage value. Since the first voltage is rich in low-frequency components, a larger ratio will make the operational amplifier output signal more inclined to amplify low-frequency signals, that is, enhance the bass effect. Because at this time, in order to balance the inputs at both ends, the circuit will increase the "weight" of the first voltage, which is dominated by low frequencies, so that the low-frequency components are more preserved and amplified in the final output signal. If the ratio of the first voltage value to the second voltage value is small, it means that the values ​​of the first voltage and the second voltage are close, the proportion of high-frequency components is relatively increased, and the "advantage" of the low-frequency signal is no longer obvious. When the operational amplifier outputs, the low-frequency signal does not receive sufficient weight, and the low-frequency components in the overall output signal are relatively weakened, resulting in a reduced bass adjustment effect. In summary, the larger the ratio of the first voltage to the second voltage, the greater the gain of the bass signal, and the more it tends to enhance bass; the smaller the ratio, the more the bass signal is suppressed, and the weaker the bass effect sounds. Bass adjustment can be achieved by changing the values ​​of the first and second voltages.

[0038] An active filter circuit 30 is used to filter out signal components within a preset frequency range of the output signal of the amplifier circuit 20 and output the filtered signal to the load. The active filter circuit 30 includes resistors, capacitors, and operational amplifiers.

[0039] It is easy to understand that the active filter circuit 30 used in this solution, compared to passive filters in existing technologies, can effectively reduce signal phase distortion during filtering, resulting in higher output waveform quality. Furthermore, passive filters typically only filter fixed frequencies or narrow frequency bands, with relatively fixed filtering characteristics. It is difficult to flexibly change filtering parameters such as cutoff frequency and bandwidth, leading to poor adaptability to frequency changes. Moreover, signal attenuation may be accompanied by phase distortion, which is detrimental to some phase-sensitive systems. In contrast, the active filter circuit 30 can more easily and dynamically adjust the filtering characteristics by changing some component parameters or adjusting the operational amplifier gain, achieving various filtering functions, such as rapid switching between low-pass, high-pass, band-pass, and band-stop filtering modes.

[0040] The signal output from the amplifier circuit 20 is filtered by the active filter circuit 30 to remove signal components within a preset frequency range. It should be noted that the preset frequency range is determined by the researchers and is set by adjusting the component parameters in the active filter circuit 30.

[0041] This utility model discloses a bass component adjustable filter circuit, which includes: a voltage divider filter circuit 10, an amplifier circuit 20, and an active filter circuit 30; the first terminal of the voltage divider filter circuit 10 is connected to an audio signal, the second terminal is connected to the first input terminal of the amplifier circuit 20, and the third terminal is connected to the second input terminal of the amplifier circuit 20; the output terminal and the second input terminal of the amplifier circuit 20 are interconnected, and the output terminal of the amplifier circuit 20 is connected to the input terminal of the active filter circuit 30; the voltage divider filter circuit 10 is used to divide the audio signal, outputting a first voltage that filters out high-frequency components to the first input terminal of the amplifier circuit 20, and also outputting a second voltage to the second input terminal of the amplifier circuit 20; The voltage divider filter circuit 10 is further configured to adjust the voltage values ​​of the first voltage and the second voltage according to the trigger command when a trigger command is received, thereby changing the ratio of the first voltage value to the second voltage value. The amplifier circuit 20 is configured to amplify the difference between the first voltage value and the second voltage value and output it to the active filter circuit 30. The active filter circuit 30 is configured to filter out signal components within a preset frequency range of the output signal of the amplifier circuit 20 and output the filtered signal to the load. Since the high-frequency components in the first voltage are filtered out, this invention changes the ratio of the first voltage value to the second voltage value by the voltage divider filter circuit 10, thereby changing the amplification degree of the bass signal by the amplifier circuit 20 and achieving bass adjustment.

[0042] In one embodiment, the amplification circuit 20 includes: a first operational amplifier U1;

[0043] The non-inverting input of the first operational amplifier U1 is connected to the second terminal of the voltage divider filter circuit 10, the inverting input is connected to the third terminal of the voltage divider filter circuit 10, the output is connected to the load, and the output is also connected to the inverting input.

[0044] It should be noted that the output of the first operational amplifier U1 is connected to the inverting input, forming a differential input buffer amplifier circuit 20. In this connection configuration, the first operational amplifier U1 can amplify the input differential signal. Simultaneously, due to its high input impedance and low output impedance, it acts as a buffer, effectively preventing mutual interference between the preceding and following stages.

[0045] In one embodiment, the voltage divider filter circuit 10 includes: a potentiometer PT and a first filter unit 110;

[0046] The potentiometer PT has an audio signal at one end, an input terminal of the first filter unit 110 at the second end, and a movable end connected to the inverting input terminal of the first operational amplifier U1.

[0047] The output terminal of the first filtering unit 110 is connected to the non-inverting input terminal of the first operational amplifier U1; the first filtering unit 110 is used to filter out the high-frequency components in the first voltage and output the filtered first voltage to the non-inverting input terminal of the first operational amplifier U1.

[0048] It should be noted that, referring to Figure 2 In this embodiment, a potentiometer PT is used to adjust the ratio of the first voltage value to the second voltage value. The first terminal of the potentiometer PT is connected to an audio signal, the second terminal is connected to the input terminal of the first filter unit 110, and the movable terminal is connected to the inverting input terminal of the first operational amplifier U1. The second voltage value can be adjusted by changing the position of the movable terminal, thus changing the ratio of the first voltage value to the second voltage value. The filter unit may include a low-pass filter, such as an RC circuit.

[0049] Reference Figure 3 The voltage divider filter circuit 10 further includes: a first resistor R1 and a first capacitor C1;

[0050] The first end of the first resistor R1 is connected to the audio signal, and the second end is connected to the first end of the first capacitor C1; the second end of the first capacitor C1 is connected to the first end of the potentiometer PT.

[0051] It should be noted that the audio signal first passes through the first resistor R1 and the first capacitor C1. The first capacitor C1 acts as a DC-blocking and AC-passing resistor, preventing the DC component in the input signal from entering the subsequent circuit. The first resistor R1 is a current-limiting resistor.

[0052] The voltage divider filter circuit 10 further includes: a second capacitor C2;

[0053] One end of the second capacitor C2 is connected to the movable terminal of the potentiometer PT, and the other end is connected to the inverting input terminal of the first operational amplifier U1.

[0054] It should be noted that after the signal is processed by the first resistor R1 and the first capacitor C1, it enters the first terminal of the potentiometer PT and is then split into two paths.

[0055] The first path: output from the movable terminal of potentiometer PT. This signal, after being adjusted by potentiometer PT, is output to the second capacitor C2. The second capacitor C2 prevents the DC component of the signal from proceeding to subsequent circuits, transmitting the AC signal adjusted by potentiometer PT to the inverting input terminal of the first operational amplifier U1.

[0056] The second path: output from the second terminal of potentiometer PT. This signal enters the first filter unit 110.

[0057] Reference Figure 4 The first filter unit 110 includes: a second resistor R2 and a third capacitor C3;

[0058] The second resistor R2 and the third capacitor C3 are connected in parallel. The first end of the second resistor R2 is connected to the second end of the potentiometer PT and the non-inverting input of the first operational amplifier U1, and the second end is grounded.

[0059] It should be explained that the RC circuit consisting of the second resistor R2 and the third capacitor C3 filters the electrical signal output from the second terminal of the potentiometer PT. The cutoff frequency of the RC circuit can be changed by adjusting the values ​​of the second resistor R2 and the third capacitor C3.

[0060] The first filter unit 110 further includes: a third resistor R3 and a fourth capacitor C4;

[0061] The first end of the third resistor R3 is connected to the second end of the voltage divider filter circuit 10, and the second end is connected to the first end of the second resistor R2 and the first end of the fourth capacitor C4; the second end of the fourth capacitor C4 is connected to the non-inverting input of the first operational amplifier U1.

[0062] It should be noted that the third resistor R3, the second resistor R2, and the third capacitor C3 form an RC filter circuit; wherein, the second resistor R2 and the third resistor R3 form a resistor voltage divider circuit; the first terminal of the third capacitor C3 is connected to the second terminal of the third resistor R3, and the second terminal is grounded. For high-frequency signals, the impedance of the third capacitor C3... The frequency is relatively small, where f is the signal frequency. When the signal frequency is high, high-frequency signals are easily bypassed to ground through the third capacitor C3, thus filtering out the high-frequency components. Low-frequency signals, due to the relatively large capacitive reactance of the third capacitor C3, are more likely to pass through the second resistor R2 and the third resistor R3 in subsequent circuitry. The signal after RC filtering is coupled to the non-inverting input of the first operational amplifier U1 through the fourth capacitor C4, which prevents the DC component of the signal from entering the non-inverting input.

[0063] Reference Figure 5In one embodiment, the active filter circuit 30 includes: a second filter unit 310 and a second operational amplifier U2;

[0064] The input terminal of the second filter unit 310 is connected to the output terminal of the first operational amplifier U1, the second terminal is connected to the non-inverting input terminal of the second operational amplifier U2, and the third terminal is connected to the inverting input terminal of the second operational amplifier U2; the output terminal of the second operational amplifier U2 is connected to the load; the output terminal of the second operational amplifier U2 is connected to the inverting input terminal.

[0065] The second filtering unit 310 is used to filter out the DC component of the output signal of the first operational amplifier U1 and then output the filtered signal to the inverting input terminal of the second operational amplifier U2.

[0066] The second filtering unit 310 is also used to filter out signal components within a preset frequency range of the output signal of the first operational amplifier U1, and output the filtered signal to the non-inverting input terminal of the second operational amplifier U2;

[0067] The second operational amplifier U2 is used to amplify the difference between the voltage value at the non-inverting input terminal and the voltage value at the inverting input terminal of the second operational amplifier U2 and output it to the load.

[0068] It should be noted that the second filtering unit 310 is connected to the non-inverting input and the inverting input of the second operational amplifier U2, respectively. Specifically, it filters the DC component of the output signal of the first operational amplifier U1 and outputs it to the inverting input, and filters the signal components within a preset frequency range in the output signal of the first operational amplifier U1 and outputs them to the non-inverting input. It is easy to understand that the preset frequency range is determined by the R&D personnel, and the parameters of the devices in the second filtering unit 310 are set according to the determined preset frequency range.

[0069] In one example, the second filtering unit 310 includes:

[0070] The fourth resistor R4, the fifth resistor R5, the fifth capacitor C5, and the sixth capacitor C6;

[0071] The first terminal of the fifth capacitor C5 is connected to the output terminal of the first operational amplifier U1, and the second terminal is connected to the first terminal of the fourth resistor R4 and the first terminal of the sixth capacitor C6; the second terminal of the fourth resistor R4 is connected to the inverting input terminal and the output terminal of the second operational amplifier U2; the second terminal of the sixth capacitor C6 is connected to the non-inverting input terminal of the second operational amplifier U2 and the first terminal of the fifth resistor R5; the second terminal of the fifth resistor R5 is grounded.

[0072] It should be noted that the low-pass signal output from the first operational amplifier U1 begins its processing through the second-order high-pass filter. This signal is split into two paths:

[0073] The signal first passes through the fifth capacitor C5 and the fourth resistor R4, reaching the inverting input of the second operational amplifier U2. The fifth capacitor C5 isolates the DC component, allowing only AC signals to pass through, while the fourth resistor R4 participates in shaping the subsequent wave characteristics.

[0074] The other signal passes through a high-pass filter network consisting of the fifth capacitor C5, the sixth capacitor C6, and the fifth resistor R5.

[0075] For a first-order high-pass filter composed of a single capacitor C and resistor R, as the signal frequency increases, the capacitive reactance decreases, allowing the signal to pass through the capacitor more easily, while low-frequency signals fall more across the resistor, thus attenuating low-frequency signals and allowing high-frequency signals to pass. A second-order high-pass filter, compared to the first-order, has a steeper filtering effect and can more cleanly separate high and low frequencies. The fifth resistor R5, the fifth capacitor C5, and the sixth capacitor C6 form a second-order high-pass filter. First, the fifth capacitor C5 effectively isolates the DC component. Then, the signal is further processed in the RC network composed of the fifth resistor R5 and the sixth capacitor C6. For high-frequency signals, the capacitive reactance of the sixth capacitor C6 decreases, allowing the signal to pass smoothly; for low-frequency signals, the capacitive reactance of the sixth capacitor C6 increases, blocking the signal. By changing the values ​​of the fifth capacitor C5, the sixth capacitor C6, and the fifth resistor R5, the filtering characteristics can be precisely adjusted. After being filtered by the high-pass filter network, the signal reaches the non-inverting input of the second operational amplifier U2.

[0076] Furthermore, the output and inverting input of the second operational amplifier U2 are interconnected, forming a high-pass differential input buffer amplifier path. This connection allows the second operational amplifier U2 to amplify the input differential signal, utilizing its high input impedance and low output impedance characteristics to buffer the preceding and following stages, preventing mutual interference. Additionally, the differential input method helps suppress common-mode interference and improve signal quality.

[0077] By changing the parameter values ​​of the fourth resistor R4, the fifth resistor R5, the fifth capacitor C5, and the sixth capacitor C6, the cutoff frequency of the high-pass filter network can be adjusted, thereby changing the high-pass filtering characteristics of the entire circuit. Increasing the capacitor value or decreasing the resistor value lowers the cutoff frequency, allowing fewer high-frequency signals to pass through the filter; conversely, decreasing the capacitor value or increasing the resistor value increases the cutoff frequency, allowing more high-frequency signals to pass through. In this way, the filtering effect of the circuit on signals of different frequencies can be flexibly shaped according to actual needs.

[0078] The active filter circuit 30 also includes: a seventh capacitor C7 and an eighth capacitor C8;

[0079] One end of the seventh capacitor C7 is connected to the second end of the sixth capacitor C6 and the first end of the fifth resistor R5, and the other end is connected to the non-inverting input of the second operational amplifier U2.

[0080] One end of the eighth capacitor C8 is connected to the output terminal of the second operational amplifier U2, and the first end is connected to the load.

[0081] It is easy to understand that the seventh capacitor C7 and the eighth capacitor C8 are used to isolate the DC component and only allow AC signals to pass through.

[0082] The above description is only an optional embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A bass component adjustable filter circuit, characterized in that, The adjustable bass component filter circuit includes: Voltage divider filter circuit, amplifier circuit and active filter circuit; The first terminal of the voltage divider filter circuit is connected to the audio signal, the second terminal is connected to the first input terminal of the amplifier circuit, and the third terminal is connected to the second input terminal of the amplifier circuit; the output terminal and the second input terminal of the amplifier circuit are connected to each other, and the output terminal of the amplifier circuit is connected to the input terminal of the active filter circuit. The voltage divider filter circuit is used to divide the audio signal, output a first voltage that filters out high-frequency components to the first input terminal of the amplifier circuit, and also output a second voltage to the second input terminal of the amplifier circuit. The voltage divider filter circuit is also used to adjust the voltage values ​​of the first voltage and the second voltage according to the trigger command when a trigger command is received, thereby changing the ratio of the first voltage value to the second voltage value. The amplifier circuit is used to amplify the difference between the first voltage value and the second voltage value and output it to the active filter circuit; The active filter circuit is used to filter out signal components within a preset frequency range of the amplifier circuit output signal and output the filtered signal to the load.

2. The bass component adjustable filter circuit as described in claim 1, characterized in that, The amplifier circuit includes: a first operational amplifier; The non-inverting input of the first operational amplifier is connected to the second terminal of the voltage divider filter circuit, the inverting input is connected to the third terminal of the voltage divider filter circuit, the output is connected to the load, and the output is also connected to the inverting input.

3. The bass component adjustable filter circuit as described in claim 2, characterized in that, The voltage divider filter circuit includes: a potentiometer and a first filter unit; The potentiometer has an audio signal connected to its first end, an input terminal of the first filter unit connected to its second end, and a movable end connected to the inverting input terminal of the first operational amplifier. The output terminal of the first filtering unit is connected to the non-inverting input terminal of the first operational amplifier; the first filtering unit is used to filter out the high-frequency components in the first voltage and output the filtered first voltage to the non-inverting input terminal of the first operational amplifier.

4. The bass component adjustable filter circuit as described in claim 3, characterized in that, The voltage divider filter circuit further includes: a first resistor and a first capacitor; The first end of the first resistor is connected to the audio signal, and the second end is connected to the first end of the first capacitor; the second end of the first capacitor is connected to the first end of the potentiometer.

5. The bass component adjustable filter circuit as described in claim 4, characterized in that, The voltage divider filter circuit further includes: a second capacitor; One end of the second capacitor is connected to the movable terminal of the potentiometer, and the other end is connected to the inverting input terminal of the first operational amplifier.

6. The bass component adjustable filter circuit as described in claim 3, characterized in that, The first filter unit includes: a second resistor and a third capacitor; The second resistor and the third capacitor are connected in parallel. The first end of the second resistor is connected to the second end of the potentiometer and the non-inverting input of the first operational amplifier, and the second end is grounded.

7. The bass component adjustable filter circuit as described in claim 6, characterized in that, The first filter unit further includes: a third resistor and a fourth capacitor; The first end of the third resistor is connected to the second end of the voltage divider filter circuit, and the second end is connected to the first end of the second resistor and the first end of the fourth capacitor; the second end of the fourth capacitor is connected to the non-inverting input of the first operational amplifier.

8. The bass component adjustable filter circuit as described in claim 2, characterized in that, The active filter circuit includes: a second filter unit and a second operational amplifier; The input terminal of the second filter unit is connected to the output terminal of the first operational amplifier, the second terminal is connected to the non-inverting input terminal of the second operational amplifier, and the third terminal is connected to the inverting input terminal of the second operational amplifier; the output terminal of the second operational amplifier is connected to the load; the output terminal of the second operational amplifier is connected to the inverting input terminal. The second filtering unit is used to filter out the DC component of the output signal of the first operational amplifier and then output the filtered signal to the inverting input terminal of the second operational amplifier. The second filtering unit is also used to filter out signal components within a preset frequency range of the output signal of the first operational amplifier, and output the filtered signal to the non-inverting input terminal of the second operational amplifier; The second operational amplifier is used to amplify the difference between the voltage value at the non-inverting input terminal and the voltage value at the inverting input terminal of the second operational amplifier and output it to the load.

9. The bass component adjustable filter circuit as described in claim 8, characterized in that, The second filtering unit includes: Fourth resistor, fifth resistor, fifth capacitor, and sixth capacitor; The first terminal of the fifth capacitor is connected to the output terminal of the first operational amplifier, and the second terminal is connected to the first terminal of the fourth resistor and the first terminal of the sixth capacitor; the second terminal of the fourth resistor is connected to the inverting input terminal of the second operational amplifier and the output terminal of the second operational amplifier; the second terminal of the sixth capacitor is connected to the non-inverting input terminal of the second operational amplifier and the first terminal of the fifth resistor; the second terminal of the fifth resistor is grounded.

10. The bass component adjustable filter circuit as described in claim 9, characterized in that, The active filter circuit further includes: a seventh capacitor and an eighth capacitor; One end of the seventh capacitor is connected to the second end of the sixth capacitor and the first end of the fifth resistor, and the other end is connected to the non-inverting input of the second operational amplifier. One end of the eighth capacitor is connected to the output terminal of the second operational amplifier, and the first end is connected to the load.

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