A loudspeaker device with adjustable directivity

Abstract

The present invention relates to an adjustable directivity loudspeaker device, comprising a box, a coupling tube arranged in the box, and a rotating mechanism for driving the coupling tube to rotate. The front side of the box has an opening, the coupling tube extends from front to back in the box to a set length, a speaker is arranged at the front end of the coupling tube, the rear end of the coupling tube is open in the box, a gap is formed between the outer wall of the coupling tube and the side wall of the box, the front end of the gap is open, the rear end of the gap is connected to the rear end of the coupling tube, the gap can allow the coupling tube to swing with a set amplitude, and the driving end of the rotating mechanism is connected to the coupling tube. The coupling tube is arranged to be rotatable and adjustable, so that only the coupling tube needs to be adjusted to mainly adjust the directivity of high-frequency sound waves, thereby adjusting the directivity of the loudspeaker, because the directivity of the loudspeaker is mainly contributed by the high frequency. Since there is no need to adjust the angle of the entire loudspeaker, the rotating mechanism does not need a lot of power, and there is no need to consider the collision of the loudspeaker with other objects.

Description

Technical Field

[0001] The invention relates to a loudspeaker device, in particular to a loudspeaker device with adjustable directivity. Background Art

[0002] Directivity is a term used to describe how the frequency response of a loudspeaker varies with off-axis angles. A speaker with wide directivity is generally considered to be one whose on-axis and off-axis responses maintain roughly the same amplitude (SPL) over a relatively large angle. A speaker with narrow directivity is one whose on-axis and off-axis responses have significantly different amplitudes (small diffusion angle).

[0003] A perfect point source loudspeaker, as long as the sound source is small relative to the wavelength, will radiate omnidirectionally, and its frequency response will not change at off-axis angles. When the wavelength starts to get smaller relative to the sound source, the sound can only radiate forward and some of the sound deviates from the axis, and we begin to see lobe-like changes in the frequency response at off-axis angles. This lobe is caused by phase cancellation, because the normal speaker unit is not a point sound source, it is closer to a circular flat plate, and the sound of different parts (such as the near side and the far side) has different phases. The lower the frequency, the closer its directivity is to omnidirectional.

[0004] There are two scenarios for the directivity of the speaker: strengthening the directivity of the speaker to make the sound directional; reducing its directivity.

[0005] There are three main methods for directional sound generation: sound-collecting enclosures; speaker arrays; and parametric arrays. All three methods have some patents and papers to discuss them. As for reducing directivity, the method of adding reflection cones or scatterers is often used, and the directivity can also be reduced by designing the shape of the speaker diaphragm (the stronger the directivity, the worse the off-axis response of the speaker, the worse the compatibility with the movement of the listener's head, and the smaller the optimal listening area).

[0006] Real-time adjustment of the directivity of a loudspeaker is a practical means, which can be used as a way to enhance directivity as well as a way to reduce directivity.

[0007] For positions that are not optimal for listening, the speaker can be made to cover this position through real-time directivity adjustment. On the one hand, it can be understood as increasing the directivity of the speaker in this direction, which increases the optimal listening position of the speaker. The equivalent result is dynamically reducing the macroscopic directivity of the speaker. The introduction of dynamic adjustment of directivity is different from the original static design of speakers. When there are fewer listeners, the overall sound field restoration performance of the speaker is increased on a large macroscopic definition.

[0008] At present, there are mainly the following methods for dynamic directivity adjustment: using a motor to dynamically adjust the direction of the sound collecting cover to adjust the directivity; using a speaker array and a directivity design to adjust the directivity; and real-time directivity adjustment of a parametric array.

[0009] Mechanically adjusting the loudspeaker structure or the sound collecting cover structure is a way to adjust the directivity. Chinese patent CN216852231U discloses a loudspeaker with adjustable directivity. It designs tripods with different angles and installs the playback unit through the tripod, so that the angle of the playback unit is different, so as to achieve the purpose of adjusting the directivity angle of the loudspeaker, and thus will not lose the sound quality and dynamics of the loudspeaker itself, greatly improving the sound quality and adjustable range of the loudspeaker. This design is a multiple, discrete design method. The tripod and baffle are designed according to the angle to be adjusted each time. It cannot be changed in real time, and can only be adjusted in one dimension of the pitch angle, and only a pitch angle change of 30° to 60° is achieved. Chinese patent CN116233662A discloses a speaker and a sound wave directivity adjustment device thereof. A horn body is set in a shell, and the horn body includes a plurality of directional waveguides. The position of the horn body in the shell is adjusted so that the corresponding waveguide outputs sound waves, thereby adjusting the vertical directivity of the sound wave. This method has the following problems: the waveguide will have standing waves at high frequencies, which will reduce the high-frequency sound quality; the extended and moving waveguide will collide with its installation and other objects on the path.

[0010] The directivity of the loudspeaker array can be corrected by the delay-sum method. Compared with the parametric array, the stability of the loudspeaker unit is usually higher, so the stability of the array is usually higher. However, the array is affected by its spatial distribution rate. If fine control is required, a large number of loudspeakers are required, and its controller is relatively complex. Therefore, the space occupied and the complex system settings limit its use, and the array dimension of the loudspeaker is related to the control dimension, that is, if you need to control the two-dimensional direction like the adjustable directivity parametric array, a two-dimensional matrix array is required. This will make the installation more difficult.

[0011] The parameter adopts ultrasonic modulation, using ultrasonic waves as carriers and taking advantage of the strong directivity of ultrasonic waves. By changing the directivity of the carrier ultrasonic waves, the directivity of the sound waves is changed. Currently, it is a method with the strongest directivity, but it has the following two main disadvantages: the replayed audio is mainly in the middle and high frequencies, and the low frequency distortion is large; the cost is high and the system is easy to damage. Summary of the invention

[0012] The purpose of the present invention is to provide a loudspeaker device with adjustable directivity, which solves the problem of how to adjust the directivity of the loudspeaker more quickly.

[0013] In order to achieve the above object, the technical solution adopted by the present invention is:

[0014] The present invention provides an adjustable directional loudspeaker device, comprising a box body, a coupling tube arranged in the box body, and a rotating mechanism for driving the coupling tube to rotate, wherein the front side of the box body has an opening, the coupling tube extends from front to rear in the box body to a set length, a speaker is arranged at the front end of the coupling tube, the rear end of the coupling tube is open in the box body, a gap is formed between the outer wall of the coupling tube and the side wall of the box body, the front end of the gap is open, the rear end of the gap is connected to the rear end of the coupling tube, the gap can allow the coupling tube to swing with a set amplitude, and the driving end of the rotating mechanism is connected to the coupling tube.

[0015] Preferably, the side wall of the box body is folded back from the front to the back and extends into the box body by a set length, and a cavity with an open rear end is formed between the folded portion and the side wall of the box body.

[0016] Preferably, the rotating mechanism is connected between the box and the coupling pipe.

[0017] Furthermore, the rotating mechanism is hidden in the box, and the power port and the signal transmission port on the rotating mechanism are located on the outer side wall of the box.

[0018] Preferably, the rotating mechanism includes a spherical gear and a first motor and a second motor driving the spherical gear to rotate from different directions respectively, and the driving ends of the first motor and the second motor are respectively provided with a first gear and a second gear meshing with the spherical gear.

[0019] Preferably, the rotating mechanism comprises a first-axis driven rotating mechanism and a second-axis driven rotating mechanism, and the first axis is orthogonal to the second axis.

[0020] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0021] The adjustable directivity loudspeaker device of the present invention has a coupling tube that is rotatable and adjustable, so that only the coupling tube needs to be adjusted to mainly adjust the directivity of high-frequency sound waves, thereby adjusting the directivity of the loudspeaker, because the directivity of the loudspeaker is mainly contributed by the high frequency. Since there is no need to adjust the angle of the entire loudspeaker, the rotating mechanism does not need a lot of power, and there is no need to consider the collision of the loudspeaker with other objects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

[0023] Figure 1 It is a structural schematic diagram of a preferred embodiment of the present invention;

[0024] Figure 2 This is the schematic diagram of the phase-inverting system formed in this example;

[0025] Figure 3 It is a structural diagram of the rotating mechanism;

[0026] Figure 4 It is a structural diagram of another rotating mechanism;

[0027] Figure 5 There are two physical pictures of blocking and opening the opening at the front end of the gap;

[0028] Figure 6 It is the sound pressure test diagram when the opening at the front end of the gap is blocked and not blocked respectively;

[0029] The reference numerals are described as follows:

[0030] 1. Box body; 11. Opening; 2. Coupling tube; 3. Rotating mechanism; 31. Spherical gear; 32. First gear; 33. Second gear; 34. First shaft drives rotating mechanism; 35. Second shaft drives rotating mechanism; 4. Speaker; 5. Gap; 6. Cavity; 7. Back cavity; 8. Coupling cavity. DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0033] like Figure 1 The adjustable directivity loudspeaker device shown comprises a box body 1, a coupling tube 2, and a rotating mechanism 3. The coupling tube 2 is arranged in the box body 1. The rotating mechanism 3 is used to drive the coupling tube 2 to rotate.

[0034] The front side of the box body 1 has an opening 11, and the coupling tube 2 extends a certain length from the front to the back in the box body 1. The front end of the coupling tube 2 is provided with a speaker 4. Figure 1 The left end of the coupling tube 2 is closed, in this case by the speaker 4. Figure 1 The middle right end) is open in the box 1.

[0035] A gap 5 is formed between the outer wall of the coupling tube 2 and the side wall of the box body 1. Figure 1 Middle left end) opening, gap 5 rear end ( Figure 1 The middle right end) is connected to the rear end of the coupling pipe 2.

[0036] The side wall of the box body 1 is folded back from the front to the back and extends a certain length into the box body 1, and a cavity 6 is formed between the folded portion and the side wall of the box body 1. The rear end of the cavity 6 is open. The cavity 6 is conducive to the formation of the inverted phase system.

[0037] The gap 5 allows the coupling tube 2 to swing with a set amplitude. The gap 5 is also used to form a phase reversal. The principle is as follows Figure 2 shown.

[0038] The coupling tube 2 has a coupling cavity 8, and the space in the box body 1 at the right end of the coupling tube 2 forms a back cavity 7. The coupling cavity 8 and the back cavity 7 cooperate with the sound mass in the gap 5 to form a phase reversal system.

[0039] like Figure 5 and Figure 6 The figure shows the experimental results that prove that the gap 5 forms a phase reversal system. The low-frequency response is improved by 10 decibels by testing a speaker that is equipped with the coupling tube 2 and the cabinet 1 to form a phase reversal system and a closed cabinet that destroys the phase reversal path. Figure 5 The left picture in the middle is a view of the outer end opening of the gap without being blocked, and the right picture is a view of the outer end opening of the gap with being blocked. Figure 6 This is a graph of sound pressure test results.

[0040] The gap 5 causes the sound waves that should be absorbed inside to be output in reverse phase and output outward together with the positive sound waves. In addition, due to the acoustic mass in the gap 5, the overall resonance frequency is reduced, thereby enhancing the bass.

[0041] The driving end of the rotating mechanism 3 is connected to the coupling tube 2. The rotating mechanism 3 is hidden in the box body 1. The power interface and the signal transmission interface on the rotating mechanism 3 are located on the outer side wall of the box body 1, so that it is not easy to be damaged and the whole device also looks more beautiful.

[0042] Figure 3The 3D schematic diagram of the rotating mechanism 3 of this example is shown in FIG. The rotating mechanism 3 includes a spherical gear 31, and the coupling tube 2 is connected to the spherical gear 31. The spherical gear 31 is driven by the first gear 32 and the second gear 33 to rotate in all directions.

[0043] The gap 5 not only forms the aforementioned phase reversal system, but also provides space for the rotation of the coupling tube 2 .

[0044] There are two common types of dual-axis rotation mechanisms. One is the ball gear control rotation in this example. The other is a separate dual-axis rotation mechanism. There are many types of these separate mechanisms, but the principles are basically the same. Figure 4 In the dual-axis, the first axis is driven to rotate by the first axis rotation mechanism 34, and the second axis is driven to rotate by the second axis rotation mechanism 35, and the first axis and the second axis are orthogonal.

[0045] Will Figure 3 and Figure 4 The rotating mechanism 3 is used to drive the coupling tube 2 to rotate, and the box 1 does not need to rotate. The sound wave passes through the coupling tube 2 and then reaches the gap 5 left for rotation. The gap 5 forms a phase reversal system, so that the low frequency of the system is not affected and the high frequency can be adjusted.

[0046] The adjustable directivity loudspeaker device of this example has the following beneficial effects:

[0047] 1. The coupling tube 2 is driven to rotate by the motor, instead of the motor driving the speaker device to rotate as a whole, thus reducing the load of the motor.

[0048] 2. The coupling tube 2 is driven to rotate by the motor, thereby avoiding interference and collision problems caused by the rotating box 1.

[0049] 3. Since the angle is adjustable in two degrees of freedom, the pointing dimension is higher and can be adjusted continuously.

[0050] 4. In the design of the rotating unit, how to make the seal is the most important issue, and the seal has a great impact on the low frequency. Many applications directly rotate the cabinet, or rotate the tweeter (the tweeter requires a very small back cavity, which can be equivalent to a rotating cabinet). This design avoids the sealing problem of back cavity leakage through the design of the coupling cavity, and the coupling cavity and the back cavity form a phase reversal system, which further improves the overall low-frequency response. The high-frequency direction can be adjusted by rotating the coupling cavity.

[0051] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the contents of the present invention and implement them accordingly. They cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. An adjustable directivity loudspeaker device, characterized in that: The invention comprises a housing (1), a coupling tube (2) arranged in the housing (1), and a rotating mechanism (3) for driving the coupling tube (2) to rotate. The housing (1) has an opening (11) on the front side. The coupling tube (2) extends from the front to the rear in the housing (1) by a set length. A horn (4) is arranged at the front end of the coupling tube (2). The rear end of the coupling tube (2) is open in the housing (1). A gap (5) is formed between the outer wall of the coupling tube (2) and the side wall of the housing (1). The front end of the gap (5) is open and the rear end of the gap (5) is connected to the coupling tube ( 2) the rear end is connected, the side wall of the box (1) is folded back from the front to the rear and extends into the box (1) by a set length, a cavity (6) with a rear end open is formed between the folded portion and the side wall of the box (1), the coupling tube (2) is a coupling cavity (8), the space in the box (1) at the right end of the coupling tube (2) is formed as a back cavity (7), the coupling cavity (8) and the back cavity (7) cooperate with the sound mass in the gap (5) to form a phase reversal system, the gap (5) can allow the coupling tube (2) to swing with a set amplitude, and the driving end of the rotating mechanism (3) is connected to the coupling tube (2).

2. The adjustable directivity loudspeaker device according to claim 1, characterized in that: The rotating mechanism (3) is connected between the box body (1) and the coupling pipe (2).

3. The adjustable directivity loudspeaker device according to claim 2, characterized in that: The rotating mechanism (3) is hidden in the box (1), and the power port and the signal transmission port on the rotating mechanism (3) are located on the outer side wall of the box (1).

4. The adjustable directivity loudspeaker device according to claim 1, characterized in that: The rotating mechanism (3) comprises a spherical gear (31) and a first motor and a second motor for driving the spherical gear (31) to rotate in different directions respectively, and the driving ends of the first motor and the second motor are respectively provided with a first gear (32) and a second gear (33) meshing with the spherical gear (31).

5. The adjustable directivity loudspeaker device according to claim 1, characterized in that: The rotating mechanism (3) comprises a first-axis driven rotating mechanism (34) and a second-axis driven rotating mechanism (35), and the first axis is orthogonal to the second axis.

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