A personal audio system and its application

Abstract

This invention discloses a personal audio system and its application. The key technical features include a housing containing a right front speaker, a left front speaker, and a controller. A right rear conduit is provided on the right front speaker. One end of the right rear conduit is tightly connected to and sealed to one side of the right front speaker, while the other end is away from the ear. The right front speaker and the left front speaker are symmetrically arranged. This personal audio system does not require contact with the ear, thus reducing user burden and providing comfortable use. It offers good sound quality with rich bass. Adding a cavity to a speaker increases the resonant frequency, resulting in poor bass. However, adding a conduit lowers the resonant frequency, leading to richer bass. It also provides good privacy, avoiding disturbing others and enhancing the privacy of communication.

Description

[Technical field]

[0001] The present invention relates to the field of audio equipment for replaying music, in particular to a personal audio system which can be used as a headrest or neckrest in environments such as cars, airplanes, and high-speed trains. [Background technology]

[0002] Most of the speakers of modern car audio are installed in the door panels or on the center console. This installation method has the following disadvantages:

[0003] 1. The sound field is not centered: Since the seats are at different distances from the door panels on both sides, the time and intensity of the sound emitted by the left and right speakers reaching the human ear are different, so the sound field cannot be centered.

[0004] 2. Sound field is difficult to zone: With the development of society, more and more people want to listen to their favorite music in the car, or not be disturbed when the people next to them are listening to music, or do not want the people next to them to hear the conversation of the remote communication party when they communicate through the car audio. The current car audio cannot meet this demand.

[0005] 3. High cost: The mid-to-high-end car audio systems on the market currently have a huge number of speakers. For example, the Cadillac CT6 has 34 speakers, and the new generation of products has 48 speakers.

[0006] Although earphones can overcome most of the above-mentioned shortcomings, they need to be worn on people's heads, which causes a certain degree of inconvenience. In addition, the earphones block people's ears, making it inconvenient to communicate with people next to them.

[0007] Some seats are equipped with speakers to play music for personal enjoyment. However, this design adopts the design concept of a speaker box. Since the speakers and boxes that can be installed on the seats are small, the bass effect is very poor and cannot meet the requirements of high-quality music playback. [Summary of the invention]

[0008] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a personal audio system which can be installed on a headrest on a seat or a neckrest worn on a person's shoulders.

[0009] Since the sound waves radiated from the front and back of the speaker have the same amplitude and opposite phases, in the absence of any obstruction, the sound waves radiated from the front and back cancel each other out, resulting in poor bass. This is called an acoustic short circuit. In order to prevent acoustic short circuits and improve bass, it is necessary to find a way to prevent the sound waves from the front and back of the speaker from radiating into the same space. The cavity of the speaker confines the sound waves from the back of the speaker to an independent space, but the addition of this cavity will cause the lowest resonant frequency of the speaker to increase, resulting in poor bass. The present invention will adopt a new design concept to prevent or reduce the impact of acoustic short circuits.

[0010] One characteristic of sound waves is that the amplitude attenuates by half (6dB) every time the propagation distance in the free field space doubles. Therefore, if the speaker and the listening position can remain relatively stable, we can use a duct to send the sound waves from one side of the speaker to a farther distance, and the other side to the ear. In this way, when the sound waves at the far end propagate back to the ear in the free field space, the amplitude is much smaller than the sound waves at the near end, thus achieving a good bass effect. Especially when the difference in the propagation distance in the free field space is not less than 8 times, the amplitude of the cancellation is less than 1dB, which can be equivalent to no mutual cancellation. Moreover, adding a duct to the speaker can reduce the speaker's lowest resonant frequency and improve the bass.

[0011] However, for people far away (more than 500mm away), the propagation distance of the sound waves from the front and back of the speaker is almost the same, and they are still in a state of similar amplitude and opposite phase, which can cancel each other out, thereby reducing the interference to people far away. In this way, high-quality private sound reproduction can be achieved.

[0012] Since the device does not need to cover the user's ears, it does not hinder the user from communicating with others or hearing useful sounds outside. And whether it is installed on a seat or worn on the shoulder, it greatly reduces the burden on the user.

[0013] The present invention is achieved through the following technical solutions:

[0014] A personal audio system, characterized in that: it includes a shell 10, in which a right front speaker 31, a left front speaker 32 and a controller 50 are respectively arranged; a right rear duct 41 is arranged on the right front speaker 31, one end opening of the right rear duct 41 is tightly connected to a surface of the right front speaker 31 and sealed with each other, and the other end opening of the right rear duct 41 is away from the human ear; a left rear duct 42 is arranged on the left front speaker 32, one end opening of the left rear duct 42 is tightly connected to a surface of the left front speaker 32 and sealed with each other, and the other end opening of the left rear duct 42 is away from the human ear, and the right rear duct 41 is not connected to the left rear duct 42.

[0015] The personal audio system as described above is characterized in that: a right front duct 43 is provided on the right front speaker 31, one end opening of the right front duct 43 is tightly connected to the other side of the right front speaker 31 and sealed with each other, and the other end opening of the right front duct 43 is close to the ear of the user; a left front duct 44 is provided on the left front speaker 32, one end opening of the left front duct 44 is tightly connected to one side of the left front speaker 32 and sealed with each other, and the other end opening of the left front duct 44 is close to the ear of the user.

[0016] The personal audio system as described above is characterized in that: the right front speaker 31 and the left front speaker 32 have the same structure and are symmetrically arranged, the left front duct 44 and the right front duct 43 have the same structure and are symmetrically arranged, the distance a between the right front duct 43 and the ear canal opening is between 30 mm and 200 mm, the distance b from the far end of the right rear duct 41 radiated into the air and then transmitted to the human ear, b / a>2.

[0017] The personal audio system as described above is characterized in that: b / a>8; the cross-sectional area error of the right front duct 43 and the right rear duct 41 does not exceed 10%, and the length error does not exceed 10%.

[0018] The personal audio system as described above is characterized in that: the right front speaker 31 and the left front speaker 32 have the same structure and are symmetrically arranged, the right rear duct 41 and the left rear duct 42 have the same structure and are symmetrically arranged, the radiation axes of the right front speaker 31 and the left front speaker 32 are respectively directed to the two ears of the person, and the angle θ between the two axes is between 30° and 170°, the distance a from the front radiated sound waves of the right front speaker 31 to the ears they are directed to is between 30mm and 200mm, and the distance b from the far end of the right rear duct 41 radiated into the air and then transmitted to the human ear is b, b / a>2.

[0019] The personal audio system as described above is characterized in that: b / a>8.

[0020] The personal audio system as described above is characterized in that: the right front speaker 31 and the left front speaker 32 have the same structure and are symmetrically arranged, and a right rear speaker 33 and a left rear speaker 34 are symmetrically arranged in the shell 10, the right rear speaker 33 is reversely arranged behind the right front speaker 31, and the left rear speaker 34 is reversely arranged behind the left front speaker 32.

[0021] An application of the personal audio system as described above is characterized in that the personal audio system is installed in the headrest of a seat.

[0022] An application of the personal audio system as described above is characterized in that the personal audio system is installed in a neck pillow.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1. The personal audio system of the present invention does not need to contact the ears, does not increase the burden on the user, and is comfortable to use.

[0025] 2. The personal audio system of the present invention has good sound quality and rich bass. Adding a cavity to the speaker will cause the resonant frequency to rise, resulting in poor bass. However, adding a duct to the speaker can reduce the resonant frequency and make the bass richer.

[0026] 3. The personal audio system of the present invention has good bilateral symmetry and a natural sound field.

[0027] 4. The personal audio system of the present invention has good privacy, does not disturb others, and also enhances the privacy of communication.

Brief Description of the Drawings

[0028] Figure 1 is a schematic structural diagram of Embodiment 1 of the present invention;

[0029] Figure 2 is a structural diagram of Embodiment 2 of the present invention;

[0030] Figure 3 is a schematic diagram of the structure of Embodiment 3 of the present invention;

[0031] Figure 4 It is a structural diagram of embodiment 4 of the present invention.

[0032] In the figure: 10 is a housing, 31 is a right front speaker, 32 is a left front speaker, 50 is a controller, 41 is a right rear conduit, 43 is a right front conduit, 33 is a right rear speaker, 34 is a left rear speaker, 44 is a left front conduit, and 42 is a left rear conduit. [Specific implementation method]

[0033] The technical features of the present invention are further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can understand them.

[0034] This patent claims protection for a personal audio system, especially the mechanical structure of the audio system. The personal audio system includes a housing 10, in which a right front speaker 31, a left front speaker 32 and a controller 50 are respectively arranged. The controller 50 is used to control the speakers. The right front speaker 31 and the left front speaker 32 are symmetrically arranged. The personal audio system can be installed in the headrest of a seat, or installed in a neck pillow and worn on the shoulder.

[0035] This patent includes at least the following four embodiments.

[0036] Embodiment 1: Figure 1As shown, a personal audio system includes a housing 10 and a controller 50. In the housing 10, a left front speaker 32 and a right front speaker 31 are provided, which correspond to the left and right ears respectively. For the convenience of description, we will only introduce the design of the right channel below, and the design of the left channel is the same as that of the right channel. A right front conduit 43 is provided on one side of the right front speaker 31, and the right front conduit 43 is tightly connected with the right front speaker 31 and sealed with each other. The other end of the right front conduit 43 is close to the ear, and the distance a from the ear canal opening satisfies the condition of 30mm≤a≤200mm. The smaller the distance a is, the better the sound is without affecting the normal use of the person. The other side of the right front speaker 31 is tightly connected with the right rear conduit 41 and sealed with each other, and the right rear conduit 41 is not connected with the left rear conduit 42. The other end of the right rear conduit 41 is far away from the human ear, and the shortest propagation distance of the sound wave from the human ear is b, which satisfies the condition of b / a>2. When b / a>8, the sound effect heard by the human ear is close to the best.

[0037] The distance between the far point M and the user is usually greater than 500 mm, so the distance difference between the end of the right front duct 43 and the right rear duct 41 and the point M is c / d<1. Since the sound waves emitted from the front and back sides of the right front speaker 31 have the same amplitude and opposite phase, they can cancel each other out when propagating to point M, thereby reducing the sound heard by the person at point M. In order to achieve the best silencing effect, one of the better ways is to make the right front duct 43 and the right rear duct 41 have similar cross-sectional areas and lengths, with an error of no more than 10%.

[0038] If the right front conduit 43 and the right rear conduit 41 cannot be designed to be of similar size, precise silencing can be achieved by measuring the acoustic wave characteristics of the conduit opening and adjusting. After the design of the right front conduit 43 is finalized, measure the acoustic wave at the opening of the right rear conduit 41. If the amplitude of the acoustic wave at the opening of the right rear conduit 41 is greater than that at the opening of the right front conduit 43, the cross-sectional area of ​​the right rear conduit 41 can be reduced or the length of the right rear conduit 41 can be increased. Otherwise, increase the cross-sectional area of ​​the right rear conduit 41 or shorten its length, and adjust until the difference between the acoustic wave frequency response curves of the two conduit openings is no more than 6dB after smoothing through 1 / 3 octave.

[0039] Embodiment 2: The dimensions of the right front conduit 43 and the right rear conduit 41 of the above embodiment can be set according to requirements. When the front conduit is shortened to be completely gone, it becomes Figure 2 Embodiment. An active noise reduction device comprises a housing 10 and a controller 50, a right front speaker 31 and a left front speaker 32. In order to reduce the impact on the user, the right front speaker 31 and the left front speaker 32 are located behind or below the human ear, at a distance a from the opening of the human ear canal and 30mm≤a≤200mm. When the distance is less than 30mm, the device has a chance to contact the human ear, causing discomfort. When the distance is greater than 200mm, the sound field stability is poor and the effect is not good.

[0040] The radiation axes of the two speakers are both pointing toward the human ear, thus forming an angle θ and 30°<θ<170°. Because the design of the right front speaker 31 and the left front speaker 32 and related accessories are symmetrical, we will only introduce the design of the right channel below. The right front speaker 31 is connected to one end of the rear duct 41 and sealed with each other, and the other end of the right rear duct 41 is open away from the human ear. The shortest sound wave propagation distance from the far end opening of the rear duct 41 to the human ear is b. When b / a>2, a good bass effect can be obtained; if b / a>8, a near-optimal effect can be obtained.

[0041] For a person at the far end point M, the distance c between the right front speaker 31 and point M is almost the same as the distance d between the opening of the rear duct 41 and point M, so the sound waves radiated from the front and back of the right front speaker 31 still meet the cancellation conditions at point M. In order to achieve the best noise reduction effect, it is necessary to adjust according to the sound wave characteristics of the right front speaker 31 and the opening of the rear duct 41. Usually, the sound waves radiated by the right front speaker 31 are relatively large, and the radiation area of ​​the opening of the right front speaker 31 needs to be adjusted. Reducing the opening area and increasing the radiation damping can reduce the sensitivity of the sound waves directly radiated by the right front speaker 31, and achieve the best cancellation effect with a frequency response curve that is no more than 6dB different after being smoothed by 1 / 3 octave.

[0042] Implementation three: Figure 3 is Figure 2 On the basis of the embodiment, a right rear speaker 33 and a left rear speaker 34 are added. The rear speakers play the same sound waves radiated outwards as the front speakers, but in opposite phases.

[0043] Since the right rear duct 41 and the left rear duct 42 are added behind the right front speaker 31 and the left front speaker 32, respectively, the sound waves at the outlet of the rear ducts (41 and 42) will be smaller than the sound waves radiated by the right front speakers (31 and 32), so the rear speakers (33 and 34) are added. The difference is calculated by measuring the sound waves directly radiated by the right front speakers (31 and 32) and the sound waves radiated at the outlet of the rear ducts (41 and 42). Then, the response characteristics of the rear speakers (33 and 34) are controlled by the controller 50 so that the sound waves reproduced by the rear speakers (33 and 34) are just equal to the difference, thereby achieving a better silencing effect.

[0044] Embodiment 4: Figure 4 The embodiments of Figure 3 Based on the embodiment of the present invention, the rear ducts (41 and 42) are eliminated, which saves costs. The sound waves radiated to the surrounding space by the front speakers (31 and 32) are completely offset by the rear speakers (33 and 34). This design can achieve Figure 3 Most of the features of the , but the bass effect will be slightly worse.

[0045] The embodiments described in the present invention are merely descriptions of the preferred implementation modes of the present invention, and are not intended to limit the concept and scope of the invention. Without departing from the design concept of the present invention, various modifications and improvements made to the technical solutions of the present invention by engineers and technicians in this field should all fall within the protection scope of the present invention.

Claims

1. A personal audio system, characterized in that: The invention comprises a shell (10), wherein a right front speaker (31), a left front speaker (32) and a controller (50) are respectively arranged in the shell (10); a right rear duct (41) is arranged on the right front speaker (31), one end opening of the right rear duct (41) is tightly connected to one side of the right front speaker (31) and sealed with each other, and the other end opening of the right rear duct (41) is away from the human ear; a left rear duct (42) is arranged on the left front speaker (32), one end opening of the left rear duct (42) is tightly connected to one side of the left front speaker (32) and sealed with each other, and the other end opening of the left rear duct (42) is away from the human ear, and the right rear duct (41) is not connected with the left rear duct (42).

2. The personal audio system according to claim 1, characterized in that: The right front speaker (31) is provided with a right front duct (43), one end opening of the right front duct (43) is tightly connected to the other side of the right front speaker (31) and sealed with each other, and the other end opening of the right front duct (43) is close to the ear of the user; the left front speaker (32) is provided with a left front duct (44), one end opening of the left front duct (44) is tightly connected to one side of the left front speaker (32) and sealed with each other, and the other end opening of the left front duct (44) is close to the ear of the user.

3. The personal audio system according to claim 2, characterized in that: The right front speaker (31) and the left front speaker (32) have the same structure and are symmetrically arranged, the left front conduit (44) and the right front conduit (43) have the same structure and are symmetrically arranged, the distance a between the right front conduit (43) and the ear canal opening is between 30 mm and 200 mm, and the distance b from the far end of the right rear conduit (41) radiated into the air and then transmitted to the human ear, b / a>2.

4. The personal audio system according to claim 3, characterized in that: b / a>8; the cross-sectional area error of the right front conduit (43) and the right rear conduit (41) does not exceed 10%, and the length error does not exceed 10%.

5. The personal audio system according to claim 1, characterized in that: The right front speaker (31) and the left front speaker (32) have the same structure and are symmetrically arranged. The right rear duct (41) and the left rear duct (42) have the same structure and are symmetrically arranged. The radiation axes of the right front speaker (31) and the left front speaker (32) are respectively directed to two ears of a person, and the angle θ between the two axes is between 30° and 170°. The distance a from the sound waves radiated from the front of the right front speaker (31) to the ears they are directed to is between 30 mm and 200 mm. The distance b from the far end of the right rear duct (41) radiated into the air and then transmitted to the human ear is b, and b / a>2.

6. The personal audio system according to claim 5, characterized in that: b / a>8.

7. The personal audio system according to claim 1, characterized in that: The right front speaker (31) and the left front speaker (32) have the same structure and are symmetrically arranged. A right rear speaker (33) and a left rear speaker (34) are symmetrically arranged in the housing (10). The right rear speaker (33) is arranged in reverse to the rear of the right front speaker (31), and the left rear speaker (34) is arranged in reverse to the rear of the left front speaker (32).

8. An application of the personal audio system according to any one of claims 1 to 7, characterized in that: The personal audio system is installed in the headrest of the seat.

9. An application of the personal audio system according to any one of claims 1 to 7, characterized in that: The personal audio system is installed in the neck pillow.

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