Patent Publication Number: US-10779079-B1

Title: Sound propagating device and loudspeaker having the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This non-provisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No(s). 108133416 filed in R.O.C. Taiwan on Sep. 17, 2019, the entire contents of which are hereby incorporated by reference. 
     TECHNICAL FIELD 
     The disclosure relates to a sound propagating device, more particularly to a sound propagating device having a sound-reflecting component and a loudspeaker having the sound propagating device. 
     BACKGROUND 
     With the development of technology and the continual pursuit of lifestyle upgrading, for the purpose of better entertainment viewing pleasure while using entertainment electronics, such as smartphone, computer, or TV to watch movies or listen music, more and more people prefer to use a wireless loudspeaker to play sounds. As smart home technology progresses to further increases the demand for smart loudspeakers, recently, many loudspeakers with artificial intelligence have been introduced in the market. 
     This type of loudspeaker can be placed anywhere in the room and can interact with users around it. The feature that a loudspeaker produces radiation of sound with different sound pressure-frequency in different directions is called “directivity”. The higher the frequency of the sound, the more obvious the directivity will be. To give the same listening experience to every listener in the room, an omnidirectional loudspeaker is provided to give the same sound pressure-frequency characteristics in all directions. Therefore, the omnidirectional loudspeaker is a loudspeaker that can radiate sound evenly in a 360-degree pattern for more uniform coverage and balanced sound quality for every listener in the room. 
     However, the conventional omnidirectional loudspeaker discards the advantages of the directional loudspeaker, while the conventional directional loudspeaker cannot achieve the effect of the omnidirectional loudspeaker, either. In the current market, there is yet no loudspeaker that can achieve both advantages of the omnidirectional and directional loudspeakers, and which remains one of the important topics in the field. 
     SUMMARY 
     One embodiment of the disclosure provides a loudspeaker including a housing, a speaker unit, a sound-reflecting component, a first baffle plate, a second baffle plate, and a baffle assembly. The speaker unit is located in the housing and having a sound outputting side. The sound-reflecting component is located in the housing and has a conical surface. The sound outputting side of the speaker unit faces toward the conical surface. The first baffle plate and the second baffle plate are respectively connected to two opposite ends of the baffle assembly. The first baffle plate, the second baffle plate, and the baffle assembly are moveably located on the conical surface. An angle between the first baffle plate and the second baffle plate is changed when at least one of the first baffle plate and the second baffle plate is moved. 
     Another embodiment of the disclosure provides a sound propagating device including a sound-reflecting component, a first baffle plate, a second baffle plate, and a baffle assembly. The sound-reflecting component has a conical surface. The first baffle plate and the second baffle plate are respectively connected to two opposite ends of the baffle assembly. The first baffle plate, the second baffle plate, and the baffle assembly are moveably located on the conical surface. An angle between the first baffle plate and the second baffle plate is changed when at least one of the first baffle plate and the second baffle plate is moved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will become better understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only and thus are not intending to limit the present disclosure and wherein: 
         FIG. 1  is a side cross-sectional view of a loudspeaker according to one embodiment of the disclosure; 
         FIGS. 2-3  are perspective views of the loudspeaker in  FIG. 1 , taken from different angles; 
         FIG. 4  is a partial exploded view of the loudspeaker in  FIG. 3 ; 
         FIG. 5  is an exploded view of a directivity adjustment assembly of the loudspeaker in  FIG. 1 ; 
         FIG. 6  is a top view of the loudspeaker in  FIG. 1 ; 
         FIG. 7  shows a frequency response analysis of the loudspeaker in  FIG. 1  performed in different angles between the first baffle plate and the second baffle plate; 
         FIGS. 8A-8B  are exploded views of an actuating mechanism of the loudspeaker in  FIG. 1 , taken from different angles; 
         FIG. 9  is a partial enlarged side view of the loudspeaker in  FIG. 1 ; 
         FIG. 10  is a partial enlarged side view of a loudspeaker according to another embodiment of the disclosure; 
         FIG. 11  is a partial enlarged side view of a loudspeaker according to still another embodiment of the disclosure; and 
         FIG. 12  is a partial enlarged side view of a loudspeaker according to yet another embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. 
     In addition, for the purpose of simple illustration, well-known structures and devices are drawn schematically, and some components or unnecessary details may be omitted from the drawings. And the size or ratio of the features in the drawings of the present disclosure may be exaggerated for illustrative purposes, but the present disclosure is not limited thereto. Note that the actual size and designs of the product manufactured based on teaching and suggestion of the present disclosure may also be properly modified according to any actual requirement. 
     Further, terms, such as “end”, “part”, “portion” or “area” may be used in the following to describe specific element and structure or specific technical feature on or between them, but these elements, structure and technical feature are not limited by these terms. Also, in the following, it may use terms, such as “substantially”, “approximately” or “about”; when these terms are used in combination with size, concentration, temperature or other physical or chemical properties or characteristics, they are used to express that, the deviation existing in the upper and/or lower limits of the range of these properties or characteristics or the acceptable tolerances caused by the manufacturing tolerances or analysis process, would still able to achieve the desired effect. 
     Furthermore, unless otherwise defined, all the terms used in the disclosure, including technical and scientific terms, have their ordinary meanings that can be understood by those skilled in the art. Moreover, the definitions of the above terms are to be interpreted as being consistent with the technical fields related to the disclosure. Unless specifically defined, these terms are not to be construed as too idealistic or formal meanings. 
     Firstly, referring to  FIGS. 1-4 ,  FIG. 1  is a side cross-sectional view of a loudspeaker  1  according to one embodiment of the disclosure,  FIGS. 2-3  are perspective views of the loudspeaker  1  in  FIG. 1 , taken from different angles, and  FIG. 4  is a partial exploded view of the loudspeaker  1  in  FIG. 3 . 
     In this embodiment, the loudspeaker  1  includes a housing  10 , a cone  20 , a speaker unit  30 , and a directivity adjustment assembly  40 . As shown in the figures, the cone  20 , the speaker unit  30 , and the directivity adjustment assembly  40  may be accommodated in the housing  10 . It should be noted that, for the purpose of viewing the interior of the housing of the loudspeaker, the whole or part of the housing of the loudspeaker in  FIGS. 1-4  and subsequent drawings will be illustrated in a cross-sectional view or dashed line. 
     Specifically, in this embodiment or some other embodiments, the housing  10  includes a sound output case  110 , a resonance chamber case  130 , a base case  150 , and a lid  170 . The sound output case  110  is located between the base case  150  and the resonance chamber case  130 , and the resonance chamber case  130  is located between the sound output case  110  and the lid  170 . That is, the sound output case  110  and the resonance chamber case  130  are located between the base case  150  and the lid  170 . The base case  150 , in normal use, is the part of the housing  10  to be placed on a planar surface and used to support other parts, and the lid  170  is the part of the housing  10  opposite to the base case  150 ; however, the disclosure is not limited by the base case  150 , the lid  170 , and their design. 
     In this embodiment and some other embodiments, the sound output case  110  has an accommodation space AS, and the resonance chamber case  130  has a resonance chamber RC. The speaker unit  30  is installed at, for example, a side of the resonance chamber case  130  connected to the sound output case  110 , such that the sound generated by the speaker unit  30  can be amplified by the resonance chamber RC of the resonance chamber case  130  and projected forwards the accommodation space AS of the sound output case  110 . 
     Herein, note that the speaker unit  30  may be, but is not limited to, any suitable speaker that can generate sound. In this or other embodiments, the speaker unit  30  is, for example, a tweeter, but the disclosure is not limited by the type of the speaker unit  30 . In addition, the resonance chamber case  130  may be made of any material that is suitable to allow the sound generated from the speaker unit  30  to resonate, but the disclosure is either not limited thereto. Also, the shape and size of the resonance chamber RC defined by the resonance chamber case  130  can be modified according to actual requirements, but the disclosure is not limited thereto. 
     In more detail, in this embodiment or some other embodiments, the resonance chamber case  130  includes a speaker unit mounting portion  131  located at a side of the resonance chamber case  130  connected to the sound output case  110 . The speaker unit mounting portion  131  may be, but is not limited to, a through hole connected to the resonance chamber RC of the resonance chamber case  130  and the accommodation space AS of the sound output case  110 . The speaker unit  30  can be fixed at the speaker unit mounting portion  131  via, for example, adhesive, engageable features, screws, or any other suitable means. 
     In this embodiment and some other embodiments, the cone  20  can be accommodated in the accommodation space AS. The cone  20  is a sound-reflecting component configured to reflect and guide the sound generated from the speaker unit  30  outwards the sound output case  110 . Regarding the arrangement of the cone  20 , the cone  20  can be arranged in a way that its central line CL 1  is coaxial with a central line CL 2  of the speaker unit  30  to ensure that the sound generated from the speaker unit  30  can be evenly guided and reflected by the cone  20 , but the disclosure is not limited thereto. For example, in some other embodiments, the central line CL 1  of the cone  20  and the central line CL 2  of the speaker unit  30  may be non-coaxial. In more detail, in this embodiment or some other embodiments, the speaker unit  30  has a sound outputting side  31  and a rear side  32  opposite to each other, the sound outputting side  31  faces toward the cone  20  and is located in the accommodation space AS of the sound output case  110 , and the rear side  32  faces toward the resonance chamber case  130  and is located in the resonance chamber RC of the resonance chamber case  130 . The cone  20  is substantially in a cone shape and at least has a conical surface substantially facing toward the sound outputting side  31  of the speaker unit  30 , such that the sound emitted from the sound outputting side  31  of the speaker unit  30  can be reflected by the conical surface  21  so as to be guided outward the sound output case  110 . Note that the conical surface  21  can be modified to be any suitable shape for guiding the sound toward the desired direction or area according to actual requirements. For example, in another embodiment, the tip end of the cone  20  may be made sharp, flat, or rounded to a concave or convex shape, but the disclosure is not limited thereto. In addition, the cone  20 , according to actual requirements, may be made of any material that is suitable to reflect/guide the sound generated from the speaker unit  30  and is sound-impermeable to the sound generated from the speaker unit  30 , but the disclosure is either not limited thereto. The capabilities of the cone  20  in “suitable to reflect/guide the sound generated from the speaker unit  30 ” and “sound-impermeable to the sound generated from the speaker unit  30 ” can be modified according to actual requirements and are not particularly restricted. 
     Further, the sound output case  110 , according to actual requirements, may be made of any material or in any configuration that is suitable for the penetration of the sound generated from the speaker unit  30 , such as metal mesh or grill foam, but the disclosure is not limited thereto. Furthermore, the sound output case  110  may not be shaped to surround the cone  20  by 360 degrees; for example, in some other embodiments, the sound output case  110  may be in a form of multiple separated support posts (e.g., the support posts  111 ′″ in  FIG. 12  as illustrated in the later embodiment) that connects the resonance chamber case  130  and the base case  150 , in such an arrangement, the accommodation space of the sound output case becomes an open space, such that the cone  20  and the components thereon are directly exposed. 
     In this embodiment or some other embodiments, the directivity adjustment assembly  40  may be disposed in the accommodation space AS of the sound output case  110 , and at least part of the directivity adjustment assembly  40  is located between the resonance chamber case  130  and the conical surface  21  of the cone  20  so as to define a sound pressure adjustment area SPA in the accommodation space AS of the sound output case  110 . As shown in  FIGS. 1 and 2 , the sound outputting side  31  of the speaker unit  30  is located in the sound pressure adjustment area SPA. The directivity adjustment assembly  40  and the cone  20  may together form a type of sound propagating device. 
     Regarding the directivity adjustment assembly  40 , please further refer to  FIG. 5  to see the exploded view of the directivity adjustment assembly  40 . Specifically, in this embodiment or some other embodiments, the directivity adjustment assembly  40  may at least include a first baffle plate  41 , a second baffle plate  42 , a baffle assembly  43 , and a baffle guiding component  44 . 
     The baffle assembly  43  is configured to eliminate the possible gap or opening connecting to the speaker unit  30  during the relative movement of the first baffle plate  41  and the second baffle plate  42 , which helps to complete the desired space defined by the baffle assembly  43 , the first baffle plate  41 , the second baffle plate  42 , and the sound output case  110 . In one embodiment of the disclosure, the baffle assembly  43  may include a plurality of foldable structures  431 , and such arrangement makes the baffle assembly  43  become a foldable and flexible baffle plate. As shown in  FIGS. 2 and 5 , in this embodiment, the foldable structures  431  of the baffle assembly  43  are connected in a series to surround the speaker unit  30 , and each foldable structure  431  includes, for example, at least two thin plate pieces (not numbered) connected to each other. Therefore, each foldable structure  431  may at least have a fold, the folds make the baffle assembly  43  capable of being opened or closed, such that area that is defined by the baffle assembly  43  and located between the speaker unit  30  and the conical surface  21  of the cone  20  can be changed. More specifically, as the baffle assembly  43  is unfolded towards an open position, the area that is surrounded by the baffle assembly  43  and located between the speaker unit  30  and the conical surface  21  of the cone  20  may be substantially in a circular or cylindrical shape; on the other hand, as the baffle assembly  43  is folded towards a closed position, the area that is surrounded by the baffle assembly  43  and located between the speaker unit  30  and the conical surface  21  of the cone  20  may be substantially reduced to a semicircular shape or a minor segment of circular. However, the disclosure is not limited by the above configuration of the baffle assembly  43 ; for example, in some other embodiments, the baffle assembly may be replaced with two curved structures which are stacked on each other and respectively connected to the first baffle plate  41  and the second baffle plate  42  to be positioned at a side of the speaker unit  30 . 
     The baffle guiding component  44  may be, but is not limited to, a ring-shaped structure with or without ends (not numbered). The baffle guiding component  44  is disposed through the foldable structures  431  of the baffle assembly  43 , such that the baffle assembly  43  can be opened and closed along the baffle guiding component  44 . Therefore, when the baffle assembly  43  is relatively opened, the foldable structures  431  can be arranged in a form of surrounding the speaker unit  30 ; when the baffle assembly  43  is relatively closed, the plate pieces of the foldable structures  431  can be pivoted and stacked on each other so that the foldable structures  431  can be gathered at a side of the speaker unit  30 . 
     Note that the moveable range of the baffle assembly  43  on the baffle guiding component  44  is related to the actual length of the fully opened baffle assembly  43  and is also related to the length of the baffle guiding component  44 ; however, these factors all can be modified or changed according to actual requirements and are not particularly restricted. 
     In this embodiment or some other embodiments, the resonance chamber case  130  may further include a baffle guiding portion  132 . The baffle guiding portion  132  may be, but is not limited to, an annular groove formed on the surface (not numbered) of the resonance chamber case  130  facing the sound output case  110 . The annular groove surrounds the speaker unit mounting portion  131 ; that is, the annular groove surrounds the speaker unit  30  that is located in the speaker unit mounting portion  131 . At least part of the baffle assembly  43  and the baffle guiding component  44  thereon may be accommodated in the baffle guiding portion  132 . Two ends (not numbered) of the baffle guiding component  44  can be respectively fixed in position in the baffle guiding portion  132  via two fasteners  45  or any other suitable manners. As such, the baffle guiding portion  132  can provide a certain degree of restriction to the movement of the baffle assembly  43 , thus the baffle assembly  43  can only be opened or closed along the baffle guiding portion  132 . That is, the baffle guiding portion  132  is able to guide the baffle assembly  43 , such that the baffle assembly  43  can be opened or closed along a determined path surrounding the speaker unit  30  in the speaker unit mounting portion  131 . Accordingly, the baffle guiding portion  132  and the baffle guiding component  44  together form a guide mechanism for guiding or assisting the movement of the baffle assembly  43 , but such guide mechanism is exemplary and the disclosure is not limited thereto. 
     In addition, another side of the baffle assembly  43  opposite the baffle guiding portion  132  may be, but is not limited to, in contact with or pressing against the conical surface  21  of the cone  20  or having an ignorable clearance with respect to the conical surface  21  of the cone  20 , such that the baffle assembly  43  is also moved along the conical surface  21  of the cone  20  while being opened or closed. 
     In this embodiment and some other embodiments, the baffle assembly  43 , according to actual requirements, may be made of any material that is flexible and also sound-impermeable to the sound generated from the speaker unit  30 , and the baffle assembly  43  may be, but is not limited to, a single-layer or multiple-layer structure, but the disclosure is not limited thereto. Note that the capability of the baffle assembly  43  in “sound-impermeable to the sound generated from the speaker unit  30 ” can be modified according to actual requirements and is not particularly restricted. 
     In addition, in this embodiment or some other embodiments, the baffle assembly  43  may be disposed with a plurality of reinforcement plates  46 . The reinforcement plates  46  may be attached to or embedded into the plate pieces of the foldable structures  431  of the baffle assembly  43 . The material hardness of the reinforcement plate  46  may be greater than that of the baffle assembly  43 , thus the reinforcement plate  46  can help to increase the structural strength of the baffle assembly  43  to prevent the baffle assembly  43  from bending or deforming to unexpected or unwanted position while being opened or closed. Note that the quantity, thickness, shape, and material of the reinforcement plate  46  are not particularly restricted and can be modified according to actual requirements. The reinforcement plate  46  may even be omitted; for example, in some other embodiments, there may be no reinforcement plate  46  on the baffle assembly  43  if the structural strength of the baffle assembly  43  meets the requirement. 
     In this embodiment and some other embodiments, the first baffle plate  41  and the second baffle plate  42  are respectively connected to two opposite ends of the baffle assembly  43 . Regarding their positions, the first baffle plate  41 , the second baffle plate  42 , and baffle assembly  43  are located between the conical surface  21  of the cone  20  and the resonance chamber case  130 , such that the first baffle plate  41 , the second baffle plate  42 , and the baffle assembly  43  can define the sound pressure adjustment area SPA in the accommodation space AS of the sound output case  110 . As shown in the figures, the sound pressure adjustment area SPA is defined by first baffle plate  41 , the second baffle plate  42 , the baffle assembly  43 , the conical surface  21  of the cone  20 , and the resonance chamber case  130 . 
     Note that, in the drawings shown in this embodiment or some other embodiments, although the resonance chamber case  130  is arranged above the sound output case  110 , the disclosure is not limited thereto. As long as the directivity adjustment assembly  40  is located between the resonance chamber case  130  and the conical surface  21  of the cone  20  (i.e., the first baffle plate  41 , the second baffle plate  42 , and the baffle assembly  43  are located between the conical surface  21  of the cone  20  and the resonance chamber case  130 ), in some other embodiments, the sound output case  110  may be arranged above the resonance chamber case  130 , in such an arrangement, the conical surface  21  of the cone  20  may face downward while using. 
     In addition, in this embodiment and some other embodiments, the edges of the first baffle plate  41  and the second baffle plate  42  may contact or slightly touch the conical surface  21  of the cone  20  and the resonance chamber case  130  or have ignorable clearances with respect to the conical surface  21  and the resonance chamber case  130 . Specifically, as shown in the figures, in this embodiment, at least one of the first baffle plate  41  and the second baffle plate  42  may be in a shape partially matching the conical surface  21  of the cone  20  and the resonance chamber case  130 ; that is, at least one of the first baffle plate  41  and the second baffle plate  42  has a bottom edge (not numbered) matching the shape of the conical surface  21  of the cone  20 , and at least one of the first baffle plate  41  and the second baffle plate  42  has a top edge (not numbered) matching the bottom surface of the resonance chamber case  130 . As such, the completeness of the sound pressure adjustment area SPA is secured. However, the disclosure is not limited by the shapes of the first baffle plate  41  and the second baffle plate  42 ; for example, in some other embodiments, one or both of the first baffle plate and the second baffle plate of the directivity adjustment assembly may be in a shape not matching the conical surface of the cone. 
     Note that, the first baffle plate  41  and the second baffle plate  42 , according to actual requirements, may be made of any material that is suitable to reflect/guide the sound generated from the speaker unit  30  and is sound-impermeable to the sound generated from the speaker unit  30 , and the first baffle plate  41  and the second baffle plate  42  may be, but are not limited to, a single-layer or multiple-layer structure, but the disclosure is not limited thereto. Note that the capability of the first baffle plate  41  and the second baffle plate  42  in “sound-impermeable to the sound generated from the speaker unit  30 ” can be modified according to actual requirements and is not particularly restricted. 
     As the arrangement discussed above, the sound, that is emitted from the sound outputting side  31  of the speaker unit  30  and coming out of the sound output case  110 , has to travel through the sound pressure adjustment area SPA that is defined by the first baffle plate  41 , the second baffle plate  42 , the baffle assembly  43 , the conical surface  21  of the cone  20 , and the resonance chamber case  130 , thus the sound pressure-frequency characteristics of the sound emitted in a specific direction can be changed to the desired level. Accordingly, adjusting the directivity of the loudspeaker  1  is possible. 
     Specifically, in this embodiment and some other embodiments, changing the shape or size of the sound pressure adjustment area SPA can increase or decrease the degree of compression to the sound therein so as to change the sound pressure of the sound emitted in a specific direction; that is, the directivity of the loudspeaker  1  can be adjusted by changing the shape or size of the sound pressure adjustment area SPA. 
     More specifically, referring to  FIG. 6 ,  FIG. 6  is a top view of the loudspeaker  1  in  FIG. 1 , one or both of the first baffle plate  41  and the second baffle plate  42  can be moved with respect to the speaker unit  30  in the arrow A or arrow A′. During the movement of the first baffle plate  41  and the second baffle plate  42 , the angle θ between the first baffle plate  41  and the second baffle plate  42  is changed, and the baffle assembly  43  can be opened or closed by forced by the first baffle plate  41  and the second baffle plate  42 , such that the range of the sound pressure adjustment area SPA, which is defined by the first baffle plate  41 , the second baffle plate  42 , the baffle assembly  43 , the conical surface  21  of the cone  20 , and the resonance chamber case  130 , can be increased or decreased according to the changes in the positions of the first baffle plate  41  and/or the second baffle plate  42 . As show in  FIG. 6 , as the actuating mechanism  50  drives the first baffle plate  41  to pivot along the arrow A to the position of the dotted lined first baffle plate  41  and drives the second baffle plate  42  to pivot along the arrow A′ to the position of the dotted lined second baffle plate  42 , the angle θ between the first baffle plate  41  and the second baffle plate  42  is decreased to θ′ so that the sound pressure adjustment area SPA is decreased to SPA′. During such change of the sound pressure adjustment area SPA, the sound, that emitted from the speaker unit  30  and enters this area, is compressed and guided, the sound pressure of the sound emitted in the direction D 1  is increased and thus strengthening the directivity of the loudspeaker  1  in the direction D 1 . In practical use, the sound pressure of the sound emitted toward the user on the direction D 1  can be increased by adjusting the positions of the first baffle plate  41  and the second baffle plate  42  so that the user on the direction D 1  can obtain a stronger listening experience. 
     Herein, referring to  FIG. 7 ,  FIG. 7  shows a frequency response analysis of the loudspeaker in  FIG. 1  performed in different angles between the first baffle plate  41  and the second baffle plate  42 . Specifically, this analysis includes three frequency responses that were measured at a distance of approximately 10 centimeters and direction from the loudspeaker  1  under the conditions of applying the same voltage to the speaker unit  30  and three different angles (90, 180, and 270 degrees) between the first baffle plate  41  and the second baffle plate  42 . As can be clearly seen in  FIG. 7 , as the angle θ between the first baffle plate  41  and the second baffle plate  42  is reduced to 90 degrees, the sound pressure level (SPL) is higher than that as the angle θ is 180 and 270 degrees at the same position, wherein the SPL has the unit of decibels (dB). This shows that decreasing the angle θ between the first baffle plate  41  and the second baffle plate  42  to decrease the sound pressure adjustment area SPA can increase the sound pressure level to achieve a higher degree of directivity. 
     On the other hand, referring back to  FIG. 6 , the directivity of the loudspeaker  1  at a given distance and direction can be decreased by respectively pivoting the first baffle plate  41  and the second baffle plate  42  in arrow A′ and arrow A. Further, when the first baffle plate  41  and the second baffle plate  42  are pivoted to the other side opposite the direction D 1 , the sound reflected by the cone  20  can be propagated evenly in all directions, such that the loudspeaker  1  can be switched to an omnidirectional loudspeaker from a directional loudspeaker. At this moment, the sound generated from the speaker unit  30  and radiated by the cone  20  would have more balanced and consistent sound pressure-frequency characteristics in all directions. Accordingly, it is understood that the loudspeaker  1  of this embodiment can be switched between a directional loudspeaker and an omnidirectional loudspeaker by adjusting the positions of the first baffle plate  41  and the second baffle plate  42 , such that the loudspeaker  1  has both advantages of omnidirectional and directional loudspeakers. Consequently, the loudspeaker  1  can be adjusted according to different requirements and application environments to achieve high adaptability and applicability. 
     Note that the movements of the first baffle plate  41  and/or the second baffle plate  42  can be achieved manually or automatically, and the disclosure is not limited thereto. This embodiment provides an actuating mechanism  50  as an example for achieving the movements of the first baffle plate  41  and/or the second baffle plate  42 . Herein, referring back to  FIGS. 1-3  and further referring to  FIGS. 8A-9 , where  FIGS. 8A-8B  are exploded views of the actuating mechanism  50  of the loudspeaker  1  in  FIG. 1 , taken from different angles, and  FIG. 9  is a partial enlarged side view of the loudspeaker  1  in  FIG. 1 . 
     Generally, in this embodiment, the loudspeaker  1  may further include an actuating mechanism  50 . The actuating mechanism  50  may be accommodated in the housing  10 . Specifically, at least part of the actuating mechanism  50  is disposed in, for example, the sound output case  110 , and the other part of the actuating mechanism  50  is disposed in, for example, the base case  150 . The first baffle plate  41  and the second baffle plate  42  are connected to the actuating mechanism  50 , and at least one of the first baffle plate  41  and the second baffle plate  42  can be pivoted with respect to the speaker unit  30  by the actuating mechanism  50 . Therefore, the directivity adjustment assembly  40  can be moved by the actuating mechanism  50  to adjust the degree of directivity of the loudspeaker  1 . 
     In detail, in this embodiment, the actuating mechanism  50  includes an actuating component  510 , a first bevel gear  521 , a second bevel gear  522 , a shaft  530 , a first disc body  540 , a first spur gear  551 , a second spur gear  552 , and a second disc body  560 . In addition, the actuating mechanism  50  further includes a first frame body  571 , a second frame body  572 , a first spur gear bracket  581 , a second spur gear bracket  582 , a first fastener  591 , a second fastener  592 , a third fastener  593 , and a fourth fastener  594 . 
     The first disc body  540  and the second disc body  560  are located in the accommodation space AS of the sound output case  110  and spaced apart from each other. The first baffle plate  41  and the second baffle plate  42  are respectively connected to the edges of the first disc body  540  and the second disc body  560 . In this embodiment, the first baffle plate  41  and the first disc body  540  may be, but is not limited to, made of a single piece, and the second baffle plate  42  and the second disc body  560  may be, but is not limited to, made of a single piece; however, the disclosure is not limited thereto. For example, in some other embodiments, the first baffle plate  41  and the first disc body  540  may be two independent pieces fixed in position via adhesive or other suitable means, and the second baffle plate  42  and the second disc body  560  may also be two independent pieces fixed in position via adhesive or other suitable means. 
     In this embodiment, the shaft  530  has an axis AL, the first disc body  540  has a first shaft mount portion  541 , and the second disc body  560  has a second shaft mount portion  561 . The first shaft mount portion  541  and the second shaft mount portion  561  may be, but is not limited to, through holes that are aligned in the axis AL. The shaft  530  may be inserted into the second shaft mount portion  561  of the second disc body  560  and the first shaft mount portion  541  of the first disc body  540 . The second shaft mount portion  561  of the second disc body  560  is rotatably disposed on the shaft  530 , such that the second disc body  560  is rotatable with respect to the shaft  530 . The first shaft mount portion  541  of the first disc body  540  is non-rotatably fixed on the shaft  530 , such that the first disc body  540  can be rotated by being driven by the shaft  530 . 
     One end of the shaft  530  may be, but is not limited to, pivotably connected to the side of the cone  20  facing away from the resonance chamber case  130 , but the disclosure is not limited thereto. For example, in some other embodiments, the shaft  530  may be not in contact with the cone  20 . 
     The actuating component  510  is rotatably disposed at a side of the base case  150  and partially exposed from the base case  150 . In this embodiment, the actuating component  510  is, for example, a knob for the user to operate the actuating mechanism  50 . The first bevel gear  521  and the second bevel gear  522  may be, but is not limited to, gears that are meshed to each other and their axes intersect. The actuating component  510  is connected to the first bevel gear  521  via a transmission bar  523 , thus, as the actuating component  510  is rotated, the actuating component  510  can rotate the first bevel gear  521  through the transmission bar  523 . The second bevel gear  522  is fixed to another end of the shaft  530  away from the cone  20  so that the second bevel gear  522  is located at the side of the first disc body  540  away from the cone  20 . The second bevel gear  522  is engaged with the first bevel gear  521 . Therefore, as the first bevel gear  521  is rotated, the first bevel gear  521  is able to rotate the second bevel gear  522  so as to rotate the shaft  530  as well as the first disc body  540  and the first baffle plate  41  that are fixed to the shaft  530 . Note that the disclosure is not limited by the first bevel gear  521  and the second bevel gear  522  shown in the figures and their types, gear ratio, and angles of axes. 
     Further, in this embodiment, the first disc body  540  includes a first internal teeth  543 , the second disc body  560  includes a second internal teeth  563 , where the first internal teeth  543  is formed at the internal edge of the first disc body  540  and protruding towards the shaft  530 , and the second internal teeth  563  is formed at the internal edge of the second disc body  560  and protruding towards the shaft  530 . 
     The second frame body  572  and the first spur gear bracket  581  may be fixed at the side of the cone  20  away from the resonance chamber case  130  via the first fastener  591 . At least part of the first spur gear bracket  581  may be located between the second disc body  560  and the first disc body  540 . The first spur gear  551  may be fixed to the first spur gear bracket  581  via the third fastener  593  so that the first spur gear  551  is located between the first internal teeth  543  of the first disc body  540  and the first shaft mount portion  541  and engaged with the first internal teeth  543 . 
     The first frame body  571  and the second spur gear bracket  582  may be fixed on the second frame body  572  via the second fastener  592 . At least part of the second spur gear bracket  582  is located between the second disc body  560  and the first disc body  540 . The second spur gear  552  may be fixed on the second spur gear bracket  582  via the fourth fastener  594  so that the second spur gear  552  is located between the second internal teeth  563  of the second disc body  560  and the second shaft mount portion  561  and engaged with the second internal teeth  563  and the first spur gear  551 . In such an arrangement, the first internal teeth  543  of the first disc body  540  is engaged with the first spur gear  551 , the first spur gear  551  is engaged with the second spur gear  552 , and the second spur gear  552  is engaged with the second internal teeth  563  of the second disc body  560 . 
     Therefore, when the actuating component  510  is rotated to force the first disc body  540  and the first baffle plate  41  thereon to rotate about the axis AL of the shaft  530 , the first internal teeth  543  of the first disc body  540  rotates the first spur gear  551 , the rotation of the first spur gear  551  forces the second spur gear  552  to rotate, and the rotation of the second spur gear  552  forces the second internal teeth  563  of the second disc body  560  to rotate about the axis AL of the shaft  530 , such that the second baffle plate  42  that is connected to the second disc body  560  is rotated about the axis AL of the shaft  530  in a direction opposite to that the first baffle plate  41  rotates, thereby changing the angle θ between the first baffle plate  41  and the second baffle plate  42  to enlarge or reduce the range of the sound pressure adjustment area SPA, i.e., achieving the operation shown in  FIG. 6 . 
     However, the actuating mechanism  50  in the previous embodiments are exemplary for actuating the directivity adjustment assembly  40 , and the disclosure is not limited thereto. For another example, referring to  FIG. 10 , where  FIG. 10  is a partial enlarged side view of a loudspeaker  1 ′ according to another embodiment of the disclosure. Note that the main difference between the loudspeaker  1 ′ of this embodiment and the loudspeaker  1  in the previous embodiments is the design of the actuating mechanism, thus only the differences between these embodiments will be illustrated hereinafter, and the same or similar descriptions may not be repeated and can be obtained with reference to the aforementioned embodiments. Also, in  FIG. 10 , the parts the same or similar to that of the previous embodiments are designated by the same or similar reference characters or numbers. 
     In this embodiment, the loudspeaker  1 ′ includes an actuating mechanism  50 ′, the actuating mechanism  50 ′ may include a first bevel gear  521 ′, a second bevel gear  522 ′, a third bevel gear  524 ′, a shaft  530 ′, and a bevel gear bracket  583 ′. The shaft  530 ′ is fixed in the base case  150 , the bevel gear bracket  583 ′ is fixed on the shaft  530 ′. The first bevel gear  521 ′ is rotatably disposed on the bevel gear bracket  583 ′. The second bevel gear  522 ′ and the third bevel gear  524 ′ are sleeved on the shaft  530 ′ and spaced apart from each other by a given distance, and the second bevel gear  522 ′ and the third bevel gear  524 ′ are respectively engaged with different sides of the first bevel gear  521 ′. Note that the second bevel gear  522 ′ and the third bevel gear  524 ′ are rotatable with respect to the shaft  530 ′, and the first baffle plate  41  and the second baffle plate  42  are respectively connected to the second bevel gear  522 ′ and the third bevel gear  524 ′. 
     In this arrangement, as the actuating component  510  is rotated, the actuating component  510  rotates the first bevel gear  521 ′ through the transmission bar  523 , and the rotation of the first bevel gear  521 ′ simultaneously rotates the second bevel gear  522 ′ and the third bevel gear  524 ′ so as to simultaneously force the first baffle plate  41  and the second baffle plate  42  to pivot about the shaft  530 ′, achieving the purpose of changing the angle between the first baffle plate  41  and the second baffle plate  42 . 
     Alternatively, referring to  FIG. 11 , where  FIG. 11  is a partial enlarged side view of a loudspeaker  1  “according to still another embodiment of the disclosure. Note that the main difference between the loudspeaker  1 ” of this embodiment and the loudspeaker  1 ′ in the previous embodiment is the design of the actuating mechanism, thus only the differences between these embodiments will be illustrated hereinafter, and the same or similar descriptions may not be repeated and can be obtained with reference to the aforementioned embodiments. Also, in  FIG. 11 , the parts the same or similar to that of the previous embodiments are designated by the same or similar reference characters or numbers. 
     In this embodiment, the loudspeaker  1 ″ includes an actuating mechanism  50 ″ and a base case  150 ″, the actuating mechanism  50 ″ may include an actuating component  510 ″, a first bevel gear  521 ″, a second bevel gear  522 ″, a transmission bar  523 ″, a third bevel gear  524 ″, a shaft  530 ″, and a bevel gear bracket  583 ″. 
     The shaft  530 ″ is fixed in place in the base case  150 ″, and the bevel gear bracket  583 ″ is fixed on the shaft  530 ″. The first bevel gear  521 ″ is rotatably disposed on the bevel gear bracket  583 ″. The second bevel gear  522 ″ and the third bevel gear  524 ″ are sleeved on the shaft  530 ″ and spaced apart from each other by a given distance, and the second bevel gear  522 ″ and the third bevel gear  524 ″ are respectively engaged with different sides of the first bevel gear  521 ″. Note that the second bevel gear  522 ″ and the third bevel gear  524 ″ are rotatable with respect to the shaft  530 ″, and the first baffle plate  41  and the second baffle plate  42  are respectively connected to the second bevel gear  522 ″ and the third bevel gear  524 ″. The actuating component  510 ″ is connected to the first baffle plate  41  via the transmission bar  523 ″. As such, the user is allowed to pivot the first baffle plate  41  by directly operating the actuating component  510 ″. Correspondingly, the base case  150 ″ may have a groove  150 ″ for the insertion and slidable movement of the transmission bar  523 ″. 
     In this arrangement, as the actuating component  510 ″ is moved along the groove  150 ″, the actuating component  510 ″ directly pivots the first baffle plate  41  and rotates the second bevel gear  522 ″, the rotation of the second bevel gear  522 ″ rotates the first bevel gear  521 ″, and the rotation of the first bevel gear  521 ″ rotates the third bevel gear  524 ″ so as to pivot the second baffle plate  42 . As such, the purpose of changing the angle between the first baffle plate  41  and the second baffle plate  42  is achieved. Note that the actuating component  510 ″ is not restricted to be directly connected to the first baffle plate  41 ; in one embodiment, the actuating component  510 ″ may be directly connected to the second baffle plate  42 , in such a case, the movement of the actuating component  510 ″ can directly pivots the second baffle plate  42  so as to pivot the first baffle plate  41 . 
     In the previous embodiments, the actuating mechanisms can be operated in a way of being manually rotated or pushed in a given direction, but the disclosure is not limited thereto. In some other embodiments, the actuating mechanism can be electrically triggered, correspondingly, the loudspeaker may require motor, antenna and/or other suitable components for the user to remotely control the actuating mechanism via, for example, smartphone or remoter controller; in such a case, the actuating component of the actuating mechanism that is exposed from the outer surface and the hole for the actuating component both can be omitted, such that the appearance of the loudspeaker may feature simpler forms and detailing. 
     In addition, the first and second baffle plates are hidden in the loudspeaker, in some other embodiments, the outer edges of the first and second baffle plate may be coated with fluorescent pigment or added with light-emitting element so that the edges of the first and second baffle plates can emit light permeable through the housing, allowing the user to recognize the positions of the first and second baffle plates from the appearance of the loudspeaker to acknowledge the status of the directivity of the loudspeaker. 
     Further, note that the disclosure is not limited by the aforementioned actuating mechanisms. In some other embodiments, the actuating mechanism may be omitted from the loudspeaker, and the first baffle plate or the second baffle plate may be directly manually adjusted to the desired position to adjust the directivity. For example, referring to  FIG. 12 , where  FIG. 12  is a partial enlarged side view of a loudspeaker  1 ′″ according to yet another embodiment of the disclosure. Note that the main difference between the loudspeaker  1 ′″ of this embodiment and the loudspeakers in the previous embodiments is that the loudspeaker  1 ′″ does not have the actuating mechanism, thus only the differences between these embodiments will be illustrated hereinafter, and the same or similar descriptions may not be repeated and can be obtained with reference to the aforementioned embodiments. Also, in  FIG. 12 , the parts the same or similar to that of the previous embodiments are designated by the same or similar reference characters or numbers. 
     In this embodiment, the loudspeaker  1 ′″ includes a first baffle plate  41 ′″ and a second baffle plate  42 ′″ that are both rotatably connected to a shaft  530 ′″ fixed at a side of the cone  20 , and the sound output case  110 ′″ is in a form of a plurality of support posts  111 ′″ that are separated from each other to make an accommodation space AS′″ of the sound output case  110 ′″ an open space. In this arrangement, the user is allowed to touch and directly pivot the first baffle plate  41 ′″ and/or the second baffle plate  42 ′″ to change the angle between the first baffle plate  41 ′″ and the second baffle plate  42 ′″, thereby adjusting the directivity of the loudspeaker  1 ′″. 
     According to the sound propagating device and the loudspeaker having the sound propagating device as discussed in the above embodiments of the disclosure, since the first baffle plate, the second baffle plate, and the baffle assembly are moveably located on the conical surface, and the angle between the first baffle plate and the second baffle plate can be changed as at least one of the first baffle plate and the second baffle plate is forced to move, thus, in the application of loudspeaker, the area defined by the baffle assembly and located between the conical surface and the speaker unit can be enlarged or reduced by adjusting the positions of the first baffle plate and/or second baffle plate to adjust the sound pressure of the sound generated from the speaker unit, such that the sound pressure of the sound emitted toward a given direction can be increased, thereby increasing the degree of directivity of the loudspeaker in the given direction. As a result, the user in a specific area can obtain a stronger listening experience. 
     In addition, in the application of loudspeaker, the conical surface faces toward the speaker unit; therefore, when the first baffle plate and the second baffle plate are pivoted to a suitable position, the sound generated from the speaker unit can be reflected by the cone and propagated evenly in all directions, such that the loudspeaker becomes an omnidirectional loudspeaker and is able to give the same listening experience to every listener in the room. 
     As such, the sound propagating device and the loudspeaker having the sound propagating device as discussed in the above embodiments of the disclosure can achieve both advantages of the omnidirectional and directional loudspeakers. 
     It will be apparent to those skilled in the art that various modifications and variations may be made to the present disclosure. It is intended that the specification and examples be considered as exemplary embodiments only, with a scope of the disclosure being indicated by the following claims and their equivalents.