CN115119086A - Sound system and electronic equipment using the sound system - Google Patents

Abstract

The embodiment of the application discloses a sound system and electronic equipment applying the sound system. The sound system comprises a cavity, a loudspeaker, a first microphone set, a second microphone set and a processing unit, wherein the loudspeaker is arranged in the cavity and attached to a first inner wall of the cavity, an opening is formed in a second inner wall of the cavity, the first microphone set is arranged on the outer side of the first inner wall of the cavity, and the first microphone set is arranged close to the loudspeaker and used for detecting first sound power of the loudspeaker. The second microphone set is disposed near the opening, and the second microphone set is used for detecting second acoustic power of the speaker. The processing unit is configured to compensate the audio signal based on the first and second acoustic powers. By adopting the embodiment of the application, the problem that the volume of a sound system is limited and the low-frequency performance is reduced is solved, the tone quality difference caused by different positions of the loudspeaker can be compensated, and the use experience of a user is improved.

Description

Sound system and electronic equipment using the sound system

technical field

The embodiments of the present application relate to the technical field of acoustics, and in particular, to an audio system and an electronic device applying the audio system.

Background technique

With the rapid development of acoustic technology, people pay more and more attention to the sound effect of the audio system. Acoustic products (such as speakers, etc.) with larger cavity volume have better low-frequency performance.

At present, the design of light, thin and short has become the development trend of consumer acoustic products. However, reducing the volume of acoustic products will affect the quality of the output sound. Therefore, how to ensure the quality of the output sound under the condition of limited volume is a very important research topic for acoustic products.

SUMMARY OF THE INVENTION

Embodiments of the present application provide an audio system and an electronic device applying the audio system. By adopting the embodiments of the present application, the problem of reducing the volume of the audio system and reducing the low-frequency performance of the speakers can be solved, and it can compensate for the different positions of the speakers. The resulting difference in sound quality improves the user experience.

In a first aspect, an embodiment of the present application provides an audio system, the audio system includes a cavity, a speaker, a first microphone group, a second microphone group, and a processing unit; the speaker is arranged in the cavity and is attached to the On the first inner wall of the cavity, the second inner wall of the cavity is provided with an opening; the first microphone group is arranged on the outside of the first inner wall of the cavity, and the first microphone group is close to the the speaker is arranged to detect the first sound power of the speaker; the second microphone group is arranged close to the opening, and the second microphone group is used to detect the second sound power of the speaker; the processing unit is configured to compensate the audio signal based on the first sound power and the second sound power.

Using the embodiment of the present application, the first sound power and the second sound power of the speaker can be detected through two microphone groups, and the audio signal can be compensated by the processing unit to obtain a compensation signal, which can then be played through the speaker. In this way, the problem that the volume of the audio system is limited and the low-frequency performance of the speaker is reduced, the difference in sound quality caused by the different positions of the speakers can be compensated, and the user experience can be improved.

In combination with the first aspect, in a possible design, the cavity further includes a third inner wall and a fourth inner wall arranged oppositely, the first inner wall and the second inner wall are arranged oppositely, and the first inner wall is connected to The third inner wall and the fourth inner wall, and the second inner wall connects the third inner wall and the fourth inner wall. Based on such a design, the audio system can obtain the first sound power and the second sound power of the speaker.

With reference to the first aspect, in a possible design, the cavity further includes a third inner wall and a fourth inner wall, the first inner wall and the third inner wall are disposed opposite to each other, and the second inner wall and the first inner wall are opposite to each other. Four inner walls are arranged opposite to each other, the fourth inner wall connects the first inner wall and the third inner wall, and the second inner wall connects the first inner wall and the third inner wall. Based on such a design, the audio system can obtain the first sound power and the second sound power of the speaker.

In combination with the first aspect, in a possible design, the sound system further includes a sound wave guide disposed in the cavity; the sound wave guide is located between the speaker and the second microphone group. Based on such a design, the loudspeaker can be changed in phase, and the low-frequency performance of the loudspeaker can be improved.

With reference to the first aspect, in a possible design, the processing unit includes a processor and a compensation filter; the processor is electrically connected to the first microphone group and the second microphone group, and is configured to be based on the speaker The first sound power and the second sound power calculate a transfer function, and the compensation filter is configured to compensate the audio signal based on the transfer function to obtain a compensation signal. Based on such a design, the processing circuit can detect the total sound power of the speaker according to the two microphone groups, and then can calculate the transfer function of the speaker to compensate the audio signal.

With reference to the first aspect, in a possible design, the processing unit further includes a power amplifier; the power amplifier is used to amplify the compensation signal and output it to the speaker, and the compensation signal is used to pass the playback on the aforementioned speakers. Based on such a design, the speaker can amplify the compensated audio signal for playback, and can compensate for differences in sound quality caused by different positions of the speakers, thereby improving user experience.

With reference to the first aspect, in a possible design, the processing unit further includes a displacement protection circuit; the displacement protection circuit is electrically connected between the compensation filter and the power amplifier, and the displacement protection circuit uses The diaphragm displacement for protecting the loudspeaker is less than the threshold. Based on such a design, the diaphragm displacement of the loudspeaker can be within a safe threshold value, and can not be damaged under the condition of high volume, which ensures the stability and reliability of the loudspeaker.

With reference to the first aspect, in a possible design, the displacement protection circuit includes a displacement circuit; the displacement circuit is configured to obtain a displacement signal of the diaphragm displacement of the speaker according to the input audio signal. Based on this design, the stability and reliability of the speaker is guaranteed.

With reference to the first aspect, in a possible design, the displacement protection circuit includes a compressor; the compressor is used to limit the vibration displacement of the speaker not to exceed a threshold value. Based on such a design, the diaphragm displacement of the loudspeaker can be within a safe threshold value, and can not be damaged under the condition of high volume, which ensures the stability and reliability of the loudspeaker.

With reference to the first aspect, in a possible design, the displacement protection circuit includes a displacement inverse circuit; the displacement inverse circuit is used to convert the displacement signal obtained by calculation into an audio signal. Based on such a design, the diaphragm displacement of the loudspeaker can be within a safe threshold value, and can not be damaged under the condition of high volume, which ensures the stability and reliability of the loudspeaker.

With reference to the first aspect, in a possible design, the first microphone group includes a first microphone and a second microphone, and the first microphone and the second microphone are both electrically connected to the processing unit; the second microphone The group includes a third microphone and a fourth microphone, both of which are electrically connected to the processing unit. Based on this design, two microphones can detect the sound power on the front side of the speaker, and the other two microphones can detect the sound power on the rear side of the speaker.

With reference to the first aspect, in a possible design, the first microphone group includes a first microphone and a second microphone, and the first microphone and the second microphone are both electrically connected to the processing unit; the second microphone The group includes a third microphone electrically connected to the processing unit. Based on this design, two microphones can detect the sound power on the front side of the speaker, and another microphone can detect the sound power on the rear side of the speaker.

In conjunction with the second aspect, an embodiment of the present application further provides an electronic device, including a casing, and the above-mentioned audio system is installed in the casing.

The sound system and the electronic device applying the sound system provided by the embodiments of the present application. Using the embodiment of the present application, by arranging the loudspeaker close to the first inner wall of the cavity, arranging the first microphone group on the outside of the first inner wall, arranging an opening in the second inner wall, and arranging the second microphone group close to the opening, it is possible to The sound power of the speaker is detected by the first microphone group and the second microphone group, and the audio signal is compensated by the processing unit based on the first sound power and the second sound power. Therefore, the problem that the volume of the audio system is reduced and the low-frequency performance of the speaker is reduced, the difference in sound quality caused by the different positions of the speakers can be compensated, and the user experience can be improved.

Description of drawings

Figure 1 is a schematic diagram of the basic acoustic architecture of audio playback.

FIG. 2 is a schematic structural diagram of the audio system in this embodiment.

FIG. 3 is a schematic structural diagram of a speaker and a microphone in an embodiment of the present application.

FIG. 4 is a schematic structural diagram of a speaker in an embodiment of the present application.

FIG. 5 is an equivalent circuit diagram of the loudspeaker in the process of power-to-sound conversion in the embodiment of the present application.

FIG. 6 is a schematic diagram of a displacement protection circuit in an embodiment of the present application.

FIG. 7 is a schematic diagram of another embodiment of the sound system of the present application.

FIG. 8 is a schematic diagram of another embodiment of the sound system of the present application.

FIG. 9 is a schematic diagram of another embodiment of the sound system of the present application.

FIG. 10 is a schematic diagram of an electronic device in an embodiment of the present application.

Description of main component symbols

sound system 100

Shell 200

Electronic equipment 300

processing unit 10

speaker 11

Magnet 111

Magnetic upper plate 112

Magnetic lower plate 113

Magnetic Barrel 114

Voice coil 115

Voice coil bobbin 116

Diaphragm 117

Ring 118

Centering Tabs 119

Dust cover 1110

Basin stand 1111

Lead 1112

Lead terminal 1113

Crimping 1114

Cavity 12

Inner wall 121, 122, 123, 124

Opening 125, 126

Sonic guide 127

Microphones 13, 14, 15, 16

Processor 17

Compensation filter 18

Displacement Protection Circuit 19

Displacement circuits 191

Compressor 192

Displacement Inverse Circuit 193

power amplifier 20

source 30

The following specific embodiments will further illustrate the present application in conjunction with the above drawings.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments It is a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

In the description of this specification, unless otherwise specified, "plurality" refers to two or more. In the description of this specification, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first", "second" may expressly or implicitly include one or more of that feature. The terms "including", "including", "having" and their variants mean "including but not limited to" unless specifically emphasized otherwise.

As shown in FIG. 1 , in the process of converting electrical energy into sound, an audio system may generally include audio source decoding, sound effect processing, power amplification, and speaker sound generation.

However, in some possible scenarios, the volume of the audio system can be reduced according to requirements, but the frequency response of the speakers in the audio system will deteriorate, reducing the low-frequency performance and sound effect of the audio system, thereby reducing the user experience. In addition to the performance of the sound system itself, the acoustic environment in which the sound system is located is also a key factor in the sound effect.

As shown in Figure 1, the sound wave emitted by the speaker will be reflected when it hits the wall and ceiling of a closed space (such as a room), and the reflected wave will also affect the sound radiation effect of the sound source.

In one embodiment, by using an acoustic point source model to simulate the basic sound radiation characteristics of a loudspeaker, the data in Table 1 below can be obtained.

Table 1

sound radiation sound imaging principle solid angle of sound radiation Output Power free field point source 4π W Specular point source 2π 2W 2D Corner pi 4W 3D Corner π/2 8W

It can be understood that the free-field point sound source can be used to characterize the speaker radiation characteristics in the anechoic chamber, the specular reflection point sound source can be used to characterize the speaker radiation characteristics of the wall, and the 2-dimensional wall corner and 3-dimensional wall corner can be used to characterize the speaker radiation characteristics of the wall corner. characteristic.

As can be seen from Table 1 above, when the loudspeaker is placed in the center of the room, the loudspeaker can be approximated as a free-field single-point sound source. When the loudspeaker is placed close to a wall in the room, the loudspeaker can be approximated as a specular two-point sound source. When the loudspeaker is placed in the corner of the room, the loudspeaker can be compared to a four-point sound source or an eight-point sound source.

As the number and distance of the walls near the speaker are different, the energy of the sound radiation is different, and the frequency characteristics of the sound radiation are also different. It is for this reason that for the same audio device (such as a speaker), the sound effect of the speaker will be completely different depending on the placement of the speaker in the room, especially the bass effect will be significantly different, which will affect the user experience.

To this end, the embodiments of the present application provide an audio system, which solves the problem of reducing the low frequency performance due to the volume reduction of the audio system, can compensate for differences in sound quality caused by different positions of speakers, and can improve user experience.

Referring to FIG. 2 , the following will illustrate the audio system 100 provided by the embodiment of the present application with reference to the accompanying drawings and practical application scenarios.

FIG. 2 is a schematic structural diagram of an audio system 100 according to an embodiment of the present application.

In one embodiment, the sound system 100 may be located in a room.

As an example in the present application, the sound system 100 in the embodiment of the present application may include a processing unit 10 , a speaker 11 , and a cavity 12 .

In some possible embodiments, the audio system 100 may further include two microphone groups. As shown in FIG. 2 , the first microphone group may include a microphone 13 and a microphone 14 . The second microphone group may include microphone 15 and microphone 16 .

It can be understood that the microphone 13 is disposed close to the microphone 14, and the distance between the microphone 13 and the microphone 14 may be smaller than a threshold value.

The processing 10 in this embodiment may include a processor 17 , a compensation filter 18 , a displacement protection circuit 19 and a power amplifier 20 .

According to the embodiment of the present application, the compensation filter 18 may be connected between the signal source 30 and the power amplifier 20 .

It can be understood that in some practical application scenarios, the signal source 30 may be a CD player, a mobile phone, a TV, a PC, etc., and the signal source 30 is used to output an audio signal to the processing circuit 10 .

The cavity 12 may include an inner wall 121 and an inner wall 122 arranged oppositely, and an inner wall 123 and an inner wall 124 arranged oppositely.

The cavity 12 in this embodiment may have a rectangular parallelepiped structure. In some other possible embodiments, the cavity 12 may also be a cube structure.

It can be understood that the loudspeaker 11 may be disposed in the cavity 12 and be close to the inner wall 121 of the cavity 12 . The microphone 13 and the microphone 14 may be arranged side by side on the outer side of the inner wall 121 of the cavity 12 .

In a possible implementation manner, both the microphone 13 and the microphone 14 may be used to collect the first sound pressure value of the radiated sound waves of the speaker 11 .

In this embodiment, the microphone 13 and the microphone 14 are both electrically connected to the processor 17, so that the microphone 13 and the microphone 14 can transmit the collected first sound pressure value to the processor 17. The processor 17 may calculate and obtain the first sound radiation power of the speaker 11 according to the first sound pressure value.

It can be understood that the microphone 13 and the microphone 14 are both disposed outside the inner wall 121 of the cavity 12 , that is, the first microphone group can collect the sound radiation power on the positive side of the speaker 11 .

In this embodiment, a first opening 125 may be provided on the inner wall 122 of the cavity 12 . The microphone 15 and the microphone 16 are disposed close to the first opening 125 .

In a possible implementation manner, both the microphone 15 and the microphone 16 may be used to collect the second sound pressure value of the sound wave radiated from the first opening 125 .

In this embodiment, the microphone 15 and the microphone 16 are both electrically connected to the processor 17, so that the microphone 15 and the microphone 16 can transmit the collected second sound pressure value to the processor 17. The processor 17 may calculate and obtain the second sound radiation power of the speaker 11 according to the second sound pressure value.

It can be understood that the second microphone group is disposed close to the first opening 125 of the inner wall 122 of the cavity 12 , that is, the second microphone group can collect the sound radiation power of the rear side of the speaker 11 .

To this end, the processor 17 may calculate a transfer function according to the total sound power of the speaker 11 , wherein the transfer function may be a functional relationship between frequency and sound power, and may be used to reflect the listening position of the speaker 11 . Acoustic frequency characteristics.

In order to provide complete compensation at the listening position, the compensation filter 18 can compensate the audio signal output by the signal source 30 according to the target transfer function to obtain a compensation signal, wherein the compensation signal is used for the sound signal through the speaker 11 . play.

It will be appreciated that the objective transfer function can be used to reflect general acoustic trends or room characteristics.

For example, when the loudspeaker 11 vibrates in the air medium, the air can be deformed alternately in density and density, thereby radiating sound waves. According to Newton's third law, the speaker 11 itself is also subjected to the reaction force of the sound field in the medium. The magnitude of the reaction force can determine the work done by the sound source on the medium, so it can be used to explain the sound radiation of the speaker 11. ability.

It can be understood that the acoustic radiation impedance of the speaker 11 may be a function of frequency, that is, the ratio of the reaction force of the sound field received by the surface of the speaker 11 to the speed of the vibration of the speaker 11 .

Specifically, the acoustic radiation impedance can be denoted as Z _MR , then Z _MR satisfies the following formula:

Wherein, F is the reaction force of the sound field received by the surface of the speaker 11 , and V is the vibration speed of the speaker 11 . In this application, the following Z _MR can all refer to this meaning. Therefore, Z _MR can be calculated by the above formula (1).

In some possible implementations, the acoustic radiation impedance denoted as Z _MR can also satisfy the following formula:

Z _MR =R _MR +jX _MR (2)

Among them, R _MR is the acoustic radiation resistance, j is an imaginary number, and X _MR is the acoustic radiation impedance. It can be known from the above formula (1) and formula (2) that the acoustic radiation resistance R _MR can be obtained by the formula of Z _MR .

In some embodiments, the radiated sound power of the speaker 11 can be denoted as W _A , then W _A satisfies the following formula:

W _A =R _MR ×|V| ² (3)

It can be known from the above formula (3) that the change of the sound radiation power of the speaker 11 can be predicted by measuring the change of the sound radiation resistance of the speaker 11 in real time.

Referring to FIG. 3 , in some possible implementations, a microphone 13 and a microphone 14 are provided on the surface of the speaker 11 .

In the embodiment of the present application, the direction of the connection between the microphone 13 and the microphone 14 is perpendicular to the surface of the diaphragm of the speaker 11 .

It can be understood that the distance between the microphone 13 and the microphone 14 can be denoted as d. Therefore, the sound pressure collected in real time by the microphone 13 in this embodiment may be p1, and the sound pressure collected in real time by the microphone 14 may be p2.

In this embodiment, according to the relationship between the sound pressure gradient and the vibration velocity of the medium, the vibration velocity of the surface of the speaker 11 can be obtained as V(ω), then V(ω) can satisfy the following formula:

Among them, ω is the circular frequency, ρ is the air density, and d is the distance between the microphone 13 and the microphone 14 . From the above formula (4), it can be known that through the sound pressure p1 collected by the microphone 13 and the sound pressure p2 collected by the microphone 14, the vibration velocity of the surface of the speaker 11 can be calculated as V(ω).

In this embodiment, the radiation acoustic impedance Z _MR of the speaker 11 can be obtained according to the above formula (1), which satisfies the following formula:

Wherein, S is the effective radiation area of the diaphragm of the speaker 11 . Therefore, by substituting the sound pressure p1 collected by the microphone 13 and the sound pressure p2 collected by the microphone 14 into the above formula (5), the radiation acoustic impedance Z _MR of the speaker 11 can be obtained.

It can be understood that in the embodiment of the present application, the _RMR of the speaker 11 can be calculated by combining the formula (2) to be the sound radiation resistance, and the calculated sound radiation resistance _RMR can be substituted into the formula (3), and the speaker 11 can be calculated. The first acoustic radiation power W _AF (ω).

In this embodiment, the first sound radiation power W _AF (ω) of the speaker 11 may be the sound radiation power of the speaker 11 on the inner wall 121 of the cavity 12 , that is, the sound radiation on the front side of the speaker 11 power.

Similarly, in this embodiment, the sound pressure p3 collected by the microphone 15 and the sound pressure p4 collected by the microphone 16 can be used, and the second sound pressure of the speaker 11 can be calculated according to formula (1) to formula (5). Sound radiation power W _AB (ω).

In this embodiment, the second sound radiation power W _AB (ω) of the speaker 11 may be the sound radiation power of the speaker 11 on the inner wall 122 of the cavity 12 , that is, the sound radiation on the rear side of the speaker 11 power.

It can be understood that the total sound power of the speaker 11 W _A (ω)=W _AF (ω)+W _AB (ω).

Please refer to FIG. 4 , which is a schematic structural diagram of the speaker 11 in an embodiment of the present application.

It can be understood that the speaker 11 can be an electro-acoustic transducer that converts electrical signals into acoustic signals and can radiate to surrounding media. The role of the speaker to achieve electro-acoustic transducer.

As shown in FIG. 4 , in a possible scenario, the speaker 11 may include a magnetic circuit structure, a vibration structure and an auxiliary structure.

In one embodiment, the magnetic circuit structure may include a magnet 111 , a magnetically conductive upper plate 112 , a magnetically conductive lower plate 113 and a magnetically conductive crutch 114 .

The magnets 111 are disposed between the magnetically conductive upper plate 112 and the magnetically conductive lower plate 113 , and the magnetically conductive pins 114 are disposed on the magnetically conductive lower plate 113 .

The vibration structure may include a voice coil 115 , a voice coil bobbin 116 , a diaphragm 117 , a folding ring 118 , a centering support piece 119 and a dust cover 1110 .

The voice coil 115 is wound on the voice coil bobbin 116 , and the voice coil bobbin 116 surrounds the periphery of the magnetic conductive bar 114 .

The auxiliary structure may include a pot frame 1111 , a lead wire 1112 , a lead wire end 1113 , and a pressing edge 1114 .

The structure of the speaker described above is only an example, and is not intended to limit the specific structure of the speaker of the present application.

Please refer to FIG. 5 , which is an equivalent circuit diagram of the speaker 11 in the process of power-to-sound conversion.

Specifically, the following formula (6) and formula (7) can be used to characterize the relationship between the voltage Eg, the current i and the diaphragm displacement x.

是电流对时间的微分，Bl是所述扬声器11的电力转换系数，V_c是所述扬声器11的振膜振动速度；M_ms是所述扬声器11的振动质量，R_ms是力导r_ms的倒数，K_ms是力顺C_ms的倒数，

是所述扬声器11的振膜速度，

是加速度。It can be understood that Eg is the signal voltage driving the speaker 11 , i is the current flowing in the coil of the speaker 11 , Re is the DC resistance of the speaker 11 , Le is the inductance of the speaker 11 ,

is the differential of current to time, B1 is the power conversion coefficient of the loudspeaker 11, _Vc is the vibration velocity of the diaphragm of the loudspeaker 11; _Mms is the vibration quality of the loudspeaker 11, and _Rms is the force leading _rms Reciprocal, K _ms is the reciprocal of Lishun C _ms ,

is the diaphragm velocity of the speaker 11,

is the acceleration.

Further, in this embodiment, the above formula (6) and formula (7) can be combined, and the relationship between the voltage Eg and the diaphragm displacement x can be obtained according to the speaker circuit, that is, the voltage Eg and the diaphragm displacement can be obtained by discretization processing. The relationship between x is expressed as the following formula (8):

Wherein, Fs is the sampling frequency, a ₁ , a ₂ , and σ _x are intermediate numerical parameters obtained by the discretization process, and n is a certain time point, all of which depend on the physical parameters of the speaker 11 .

Referring to FIG. 6 , in some possible embodiments of the present application, after the audio signal output by the signal source 30 passes through the compensation filter 18 , the displacement protection circuit 19 can ensure the diaphragm of the speaker 11 The displacement does not exceed the threshold.

Specifically, the displacement protection circuit 19 may include a displacement circuit 191 , a compressor 192 and an inverse displacement circuit 193 .

In this embodiment, the displacement circuit 191 can be used to predict the displacement signal of the diaphragm displacement of the speaker 11 according to the input audio signal. That is, the displacement circuit 191 in this embodiment can obtain the diaphragm displacement of the speaker 11 according to the voltage value of the audio signal.

The compressor 192 is used to limit the vibration displacement of the speaker 11 not to exceed a threshold value.

The displacement inverse circuit 193 is used to convert the limited displacement signal obtained by calculation into a voltage signal.

Using the embodiment of the present application, the displacement protection circuit 19 can ensure that the voltage signal input to the power amplifier 20 is stable and reliable, thereby avoiding excessive displacement of the diaphragm of the speaker 11 and causing damage.

It can be understood that after the audio signal is amplified by the power amplifier 20, it can be output to the speaker 11, and the speaker 11 plays sound.

In some embodiments, the processing circuit 10 may further include a compensation filter 18 , a displacement protection circuit 19 and a power amplifier 20 .

It can be understood that when the positions of the speakers 11 in the room are different, the radiation capability of the speakers 11 will also change correspondingly, and the frequency characteristics of the sound power will also change.

Therefore, the compensation filter 16 in this embodiment can perform corresponding inverse adjustment according to the change of the total sound power W _A (ω) of the speaker 11 .

For example, when the loudspeaker 11 is moved from the middle of the room to the corner of the wall, the sound power output of the loudspeaker 11 will increase, especially the bass will be significantly improved, and the compensation filter 18 will reduce the low-frequency components of the signal source 30 some attenuation.

The processor 17 may transmit the total sound power _WA (ω) of the loudspeaker 11 to the compensation filter 18 . The compensation filter 18 can compensate the sound power of the speaker 11 .

Therefore, in the entire signal chain of the audio system 100 , the compensation filter 18 can form an automatic balance process with the speaker 11 and the cavity 12 , thereby avoiding excessive bass and sound from the speaker 11 . Cloudy.

By adopting the embodiment of the present application, the volume of the audio system 100 is not limited by the volume of the closed box, the stability and reliability of the audio system can be ensured, the amplitude of the diaphragm of the speaker 11 is protected from exceeding the threshold value, and the volume reduction of the audio system is solved. The problem of small and low frequency performance can be compensated for the difference in sound quality caused by the different positions of the speakers, and the user experience can be improved.

Please refer to FIG. 7 , which is a schematic structural diagram of another embodiment of the audio system 100 provided by the present application.

The difference from the embodiment of the audio system 100 shown in FIG. 2 is that, as shown in FIG. 7 , in this embodiment, a second opening 126 may be provided on the inner wall 123 of the cavity 12 . The microphone 15 and the microphone 16 may be disposed close to the second opening 126 .

In a possible implementation manner, both the microphone 15 and the microphone 16 may be used to collect the sound pressure value of the radiated sound waves from the second opening 126 .

In this embodiment, it is assumed that the sound pressure value detected by the microphone 13 is P ₁ (ω), and the sound pressure value detected by the microphone 14 is P ₂ (ω). The processor can obtain the average sound pressure P(ω) of the microphone 13 and the microphone 14 through the following formula (9).

The volume velocity U(ω) on the surface of the speaker 11 satisfies the following formula:

Among them, j is an imaginary number, ω is the circular frequency, ρ is the air density, d is the distance between the microphone 13 and the microphone 14 , and S _d is the surface area of the speaker 11 .

Therefore, in combination with formulas (9) and (10), it can be concluded that the sound radiation resistance R _A (ω) of the speaker 11 satisfies the following formula:

是取实部计算。in

is the calculation of the real part.

Therefore, through the above design, the processor 17 can calculate the total sound power W _A (ω) of the speaker 11 through the following formula (12).

It can be understood that R _AF is the sound radiation resistance of the front side of the speaker 11, R _AB is the sound radiation resistance of the rear side of the speaker 11, U _F (ω) is the volume velocity of the front side of the speaker 11, U _B ( ω) is the volume velocity of the rear side of the speaker 11 .

Therefore, in combination with the above formulas (9) to (12), the compensation of the speaker 11 by the compensation filter 18 can be expressed as:

where R _ATref (ω) can be the reference equivalent total radiation resistance measured in the reference environment. R _AT (ω) can be the actual measured total radiation resistance.

With this embodiment, the sound radiation resistance of the speaker 11 can be calculated in real time by collecting the sound pressure on the front side and the sound pressure on the rear side of the cavity 12 . When the position of the speaker 11 moves, the compensation filter 18 can adjust the input audio signal to achieve the purpose of sound field adaptation. The sound system 100 provided in this embodiment can compensate the sound quality of the speaker 11 in real time, and ensure the stable and reliable operation of the speaker 11 .

Please refer to FIG. 8 , which is a schematic structural diagram of another embodiment of the audio system 100 provided by the present application.

The difference from the embodiment of the audio system 100 shown in FIG. 2 is that, as shown in FIG. 8 , in this embodiment, the inner wall 122 of the cavity 12 may be provided with a first opening 125 , and the microphone 15 may be provided with a first opening 125 . It is arranged close to the first opening 125 .

In this embodiment, the relationship between the volume velocity _UF (ω) on the front side of the speaker 11 and the volume velocity _UB (ω) on the rear side can be expressed as:

Among them, M _AB is the sound quality of the cavity, and C _AB is the sound capacity of the cavity.

Compared with the audio system 100 shown in the embodiment of FIG. 2 , in this embodiment, only one microphone 15 needs to be disposed at the first opening 125 . Since the processor 17 can calculate the volume velocity of the speaker 11 through the sound pressure values collected by the microphone 13 and the microphone 14 , the processor 17 can detect the volume velocity according to the calculated volume velocity and the microphone 15 . The sound pressure to the rear side can be calculated to obtain the second sound power of the rear side of the speaker. Therefore, even if only one microphone 15 is provided at the first opening 125 of the cavity 12 , the total sound power of the speaker 11 can still be obtained. With this embodiment, the sound quality of the speaker 11 can be compensated in real time, and the stable and reliable operation of the speaker 11 can be ensured.

Please refer to FIG. 9 , which is a schematic structural diagram of another embodiment of the audio system 100 provided by the present application.

The difference from the embodiment of the sound system 100 shown in FIG. 8 is that, as shown in FIG. 9 , in this embodiment, the sound system 100 further includes an acoustic waveguide 21 .

In this embodiment, the speaker 11 is disposed in the cavity 12 and is disposed facing the inner wall 121 of the cavity 12 . The microphone 13 and the microphone 14 are arranged side by side on the outer side of the inner wall 121 of the cavity 12 .

A first opening 125 is provided on the inner wall 122 of the cavity 12 . The microphone 15 is disposed close to the first opening 125 . The acoustic waveguide 127 is disposed in the cavity 12 , and the acoustic waveguide 127 is located between the speaker 11 and the microphone 15 .

In this embodiment, the relationship between the volume velocity _UF (ω) on the front side of the speaker 11 and the volume velocity _UB (ω) on the rear side can be expressed as:

U _B (ω)=-U _F (ω)e ^-jωt (15)

By using the embodiments of the present application, the speaker 11 can be changed in phase, and the low frequency performance of the speaker 11 can be improved.

Wherein, t is the time difference between the sound wave on the front side of the speaker 11 and the sound wave at the first opening on the rear side.

The audio system 100 provided in the embodiment of the present application may not be limited by the volume requirement of the closed cavity. When the position of the speaker is moved, the performance of the audio system can be adaptively adjusted, and the diaphragm displacement of the speaker is within a safe threshold, It can not be damaged under high volume, which ensures the stability and reliability of the speaker.

Referring to FIG. 10 , an embodiment of the present application further provides an electronic device 300 , and the electronic device 300 may be a notebook computer, an all-in-one computer, a large-screen TV, etc., which is not limited in the present application.

As shown in FIG. 10 , the electronic device 300 may include a housing 200 in which the audio system 100 described in the above embodiments is installed. The sound system 100 in the embodiment of the present application can compensate the sound quality of the speaker in real time, and the embodiment of the present application can adaptively adjust the sound effect, and the displacement protection module ensures that the displacement of the diaphragm of the speaker does not exceed a threshold, and protects the speaker from not exceeding the threshold at high volume. damage, to ensure the stability of the speaker, which can improve the user experience.

It will be apparent to those skilled in the art that the present application is not limited to the details of the above-described exemplary embodiments, but that the present application may be embodied in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, as long as they are within the spirit and scope of the present application, appropriate changes and changes made to the above embodiments should fall within the scope of protection of the present application.

Claims (13)

1. A sound system is characterized by comprising a cavity, a loudspeaker, a first microphone group, a second microphone group and a processing unit;

the loudspeaker is arranged in the cavity and attached to the first inner wall of the cavity,

an opening is formed in the second inner wall of the cavity;

the first microphone group is arranged on the outer side of the first inner wall of the cavity and is arranged close to the loudspeaker for detecting first sound power of the loudspeaker;

the second microphone set is arranged close to the opening and used for detecting second sound power of the loudspeaker;

the processing unit is configured to compensate an audio signal based on the first and second acoustic powers.

2. Sound system as claimed in claim 1,

the cavity further comprises a third inner wall and a fourth inner wall which are oppositely arranged, the first inner wall and the second inner wall are oppositely arranged, the first inner wall is connected with the third inner wall and the fourth inner wall, and the second inner wall is connected with the third inner wall and the fourth inner wall.

3. Sound system as claimed in claim 1,

the cavity further comprises a third inner wall and a fourth inner wall, the first inner wall and the third inner wall are arranged oppositely, the second inner wall and the fourth inner wall are arranged oppositely, the fourth inner wall is connected with the first inner wall and the third inner wall, and the second inner wall is connected with the first inner wall and the third inner wall.

4. A sound system according to claim 2 or 3, further comprising:

an acoustic waveguide disposed within the cavity;

the acoustic waveguide is located between the speaker and the second microphone set.

5. Sound system according to one of the claims 1-4,

the processing unit comprises a processor and a compensation filter; the processor is electrically connected with the first microphone group and the second microphone group, and is configured to calculate a transfer function based on the first sound power and the second sound power of the loudspeaker, and the compensation filter is configured to compensate the audio signal based on the transfer function to obtain a compensation signal.

6. Sound system as claimed in claim 5,

the processing unit further comprises a power amplifier;

the power amplifier is used for amplifying the compensation signal and then outputting the compensation signal to the loudspeaker, and the compensation signal is used for playing through the loudspeaker.

7. A sound system according to claim 6,

the processing unit further comprises a displacement protection circuit;

the displacement protection circuit is electrically connected between the compensation filter and the power amplifier and is used for protecting the diaphragm displacement of the loudspeaker to be smaller than a threshold value.

8. Sound system as claimed in claim 7,

the displacement protection circuit comprises a displacement circuit;

the displacement circuit is used for obtaining a displacement signal of the diaphragm displacement of the loudspeaker according to the input audio signal.

9. Sound system as claimed in claim 7 or 8,

the displacement protection circuit comprises a voltage limiter;

the pressure limiter is used for limiting the vibration displacement of the loudspeaker not to exceed a threshold value.

10. Sound system according to one of the claims 7-9,

the displacement protection circuit comprises a displacement inverse circuit;

the displacement inverse circuit is used for converting the displacement signal obtained by calculation into an audio signal.

11. The sound system of any one of claims 1-10, further comprising:

the first microphone group comprises a first microphone and a second microphone, and the first microphone and the second microphone are both electrically connected with the processing unit;

the second microphone set comprises a third microphone and a fourth microphone, and the third microphone and the fourth microphone are both electrically connected with the processing unit.

12. The sound system of any one of claims 1-10, further comprising:

the first microphone set comprises a first microphone and a second microphone, and the first microphone and the second microphone are both electrically connected with the processing unit;

the second microphone set comprises a third microphone, and the third microphone is electrically connected with the processing unit.

13. An electronic device comprising a housing, wherein the sound system of any one of claims 1-12 is mounted within the housing.

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