Horn with constant coverage

Abstract

An example device may comprise one or more of the following components: a neck having an opening for receiving sound, a bell directing the sound, a mouthpiece opening for emitting the sound, and a variable-width slot arranged between the neck and the bell directing the sound, wherein the variable-width slot may have a lower section having a first width and an upper section having a second width greater than the first width.

Description

BACKGROUND

[0001] A horn provides an additional sound pressure level (SPL) in a specific listening area by increasing the directivity of the sound towards that area. A constant-directivity horn essentially means that the directivity and coverage of the sound within a loudspeaker's frequency range are the same from the lowest to the highest frequency. With a constant-directivity horn, the sound coverage is uniform in both the horizontal and vertical planes, both in terms of frequency response and SPL. A constant-directivity horn may include a diffraction slot through which the sound exits. The diffraction slot typically has a fixed width along its entire vertical height. However, a disadvantage of the constant-directivity horn is that the radiation at the upper end of its vertical coverage is often less useful or even unusable.This is because this part of the horn's vertical coverage is typically directed at areas farther away than the center of its vertical coverage pattern. Due to the greater distance to these more distant areas, the sound pressure level (SPL) reaching them is lower compared to the SPL in areas closer by. This can result in large variations in the SPL directed at listeners / audiences across the entire coverage pattern of the horn. SUMMARY

[0002] One embodiment provides a horn which may include one or more of the following elements: a throat with an opening for receiving sound, a mouthpiece for emitting the sound, a bell for directing the sound to the mouthpiece, a coupling transition arranged between the throat and the bell, and a variable-width slot forming the interface between the coupling transition and the bell for directing the sound, wherein the variable-width slot comprises a lower section with a first width and an upper section with a second width that is greater than the first width.

[0003] Another embodiment provides a loudspeaker arrangement which may include one or more of the following elements: a neck with an opening for receiving sound, a mouthpiece for emitting the sound, a sound source located behind the opening of the neck and configured to emit the sound in the direction of the opening of the neck, a coupling transition located between the neck and the bell, and a variable-width slot between the coupling transition and the bell that guides the sound, wherein the variable-width slot comprises a lower section with a first width and an upper section with a second width that is greater than the first width. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1A is a representation of a perspective front view of a loudspeaker arrangement according to exemplary embodiments. Fig. 1B is a representation of a detailed view of the interface of the loudspeaker arrangement. Fig. 1A according to the examples shown. Fig. 1C is a representation of a perspective rear view of the loudspeaker from Fig. 1A according to the examples shown. Fig. 1D is a representation of a perspective side view of the loudspeaker from Fig. 1A according to the examples shown. Fig. 1E is a representation of a perspective top view of the loudspeaker from Fig. 1A according to the examples shown. Fig. 1F is a representation of a perspective bottom view of the loudspeaker from Fig. 1A according to the examples shown. Fig. 1G is an illustration of an oblique perspective view of the loudspeaker from Fig. 1A according to further examples of embodiment. Fig. Figure 2 is an illustration showing an example of a loudspeaker's sound coverage area. Fig. 1A shows examples of implementation. DETAILED DESCRIPTION

[0004] Most conventional horns are described as constant-directivity horns. They aim to ensure a uniform distribution of sound pressure level (SPL) within a defined radiation angle as a function of frequency. A better goal is for a loudspeaker to ensure a uniform distribution of SPL to as many listeners as possible within a designated listening area, while simultaneously limiting the sound energy outside the intended listening area. This requires that the shape of the horn's radiation pattern differ from that of a constant-directivity horn. The embodiments described relate to a novel constant-coverage horn that can provide a sound radiation pattern that ensures a more uniform distribution of SPL to a designated audience while simultaneously limiting the SPL to areas outside the intended listening area.

[0005] The constant-coverage horn comprises a throat, through which sound is received, for example, from a driver, and a mouthpiece, through which the sound is emitted. Between the throat and the bell is a novel interface comprising a coupling transition and a variable-width slot at the end of the coupling transition. The interface slot is referred to here as a "variable-width slot" because the width of the slot changes from its beginning to its end. Specifically, the slot widens upwards and narrows downwards from its beginning to its end.

[0006] The variable-width slot causes its side walls to expand or be segmented in a curved manner, approximating a curvature. The expanding slot creates more acoustic resistance at the lower end, where it is narrower, and less at the upper end, where it is wider. This results in a more favorable sound path (lower resistance) for the sound energy in the upper section of the horn compared to the lower section, which has a less favorable path (higher resistance). Consequently, more sound energy, such as a higher SPL, is directed to the upper section of the horn. This is advantageous because the upper section of the horn directs the sound in the vertical plane to the more distant areas of the intended listening area, while the lower section covers the closer listening areas.

[0007] In general, the SPL of sound decreases with increasing distance through the air. The greater the distance traveled, the greater the attenuation of the SPL. The difference in distance to the listening areas within the horn's vertical coverage plane results in greater attenuation of the SPL for the more distant listening areas. By concentrating more SPL onto the more distant listening areas, the horn compensates for the attenuation of the SPL due to the greater propagation distance. This results in a more even distribution of the SPL across the intended listening area within the horn's vertical coverage plane.

[0008] The variable-width slot is shaped to ensure a more even distribution of the SPL within the normal planes (perpendicular to the horn's vertical radiation plane). The preferred shape makes the "horizontal" radiation angle of the sound a function of the vertical radiation angle within the horn. The upper sections of the horn direct the sound to the more distant listening areas in the vertical coverage plane, while the lower sections of the horn direct the sound to the closer listening areas in the same vertical coverage plane. To ensure an even distribution of the SPL across the listening area off-axis (e.g., the horizontal aspect of the listening area), the horizontal radiation angle of the horn must vary relative to the vertical radiation angle.

[0009] The horizontal radiation angle, which changes as a function of the vertical coverage, can cause the side walls of the slot with variable width to be curved relative to the axial dimension of the horn, rather than being the typical flat slots as in some conventional horns with constant directivity.

[0010] The constant coverage horn described here utilizes a coupling transition between the throat and bell sections of the horn, which differs significantly from previous horn designs. This coupling transition gradually changes the cross-section from the throat opening to the interface of the variable-width slot. The interface described here acts as a diffraction slot only for the lower portion of the horn's vertical coverage. The narrower horizontal coverage used in the upper portion of the horn's vertical coverage does not require a diffraction slot to achieve the desired horizontal coverage. This allows the interface to be made much wider in the upper portion. This can lead to an improvement in sound pressure level (SPL) that can be directed towards the upper portion of the horn's vertical coverage (distant listeners) compared to prior art designs.

[0011] Fig. Figure 1A shows a perspective front view 100A of a loudspeaker arrangement according to exemplary embodiments, Fig. Figure 1B shows a detailed view (100B) of the coupling transition and interface of the loudspeaker arrangement. Fig. 1A according to exemplary embodiments, and Fig. Figure 1C shows a perspective rear view of the loudspeaker 100C. Fig. 1A according to the examples shown.

[0012] With reference to the Fig. In 1A-1C, the loudspeaker arrangement comprises a throat 130, a bell 120, and a coupling transition 110 connecting the throat 130 to the bell 120. In this example, sound enters through the throat 130 and is emitted from the mouthpiece 140 of the bell 120. The coupling transition 110 directs the sound through a variable-width slot 111 located at the end of the coupling transition 110, which is further described herein. The result is that, compared to a horn with constant directivity, the distribution of sound energy is directed in a more advantageous pattern to listeners who are farther away than those who are closer.

[0013] In Fig. Figure 1A shows a front view of the bell 120, the coupling transition 110, and the variable-width slot 111. In this example, the mouthpiece 140 of the bell 120 comprises a rectangular rim with a first side 125, a top 126, a second side 127, and a bottom 128. In this example, the first side 125 and the second side 127 are of equal height, and the top 126 and the bottom 128 are of equal width. Here, the vertical height of the first side 125 and the second side 127 is greater than the width of the top 126 and the bottom 128. Sound can enter through a rear of the loudspeaker assembly and pass through the coupling transition 110 and then to the bell 120. The variable shape and size of the slot 111 with variable width results in a limitation of the sound emission at the bottom 128 of the bell 120 and a lesser limitation of the sound emission at the top 126 of the bell 120.

[0014] In relation to Fig. Figure 1B shows the coupling transition 110 with dashed lines and includes a start 114 and an end 115 along the length of the horn. Here, the start 114 of the coupling transition 110 is relatively vertical / planar in two dimensions (YZ plane), while the end 115 of the coupling transition 110 is curved and not planar in two dimensions (YZ plane). The variable-width slot 111 is located at the end of the coupling transition 110. The bell 120 begins at the variable-width slot 111, which is located at the end 115 of the coupling transition 110.

[0015] According to various embodiments, the interface slot is described as "variable width" because the shape and internal size of the slot change continuously from the bottom 115 to the top 115. Specifically, the variable width slot 111 becomes narrower at its bottom while becoming progressively wider at its top. This shape causes the sound pressure level (SPL) to be more limited at the bottom of the variable width slot 111 than at the top. The result is a more uniform radiation or coverage area for listeners standing further away.

[0016] For example, when sound enters the throat 130 of the loudspeaker array, it travels to the coupling junction 110. Here, the junction creates a stronger restriction of the sound in a lower section of the coupling junction 110, while the sound is less restricted in an upper section of the coupling junction 110. This allows sound with a higher SPL to be emitted from the upper section than from the lower section of the variable-width slot 111. The result is a more uniform sound output to a larger area of ​​the listeners at a greater distance.

[0017] In Fig. Figure 1C shows an opening of the throat 130. Sound enters through the opening of the throat 130 from a sound source such as a driver, a loudspeaker, or the like (not shown). In this example, the coupling transition 110 comprises an upper section 112, a lower section 113, and two side walls 116. Each of the side walls 116 is curved in all three dimensions. In other words, the side walls 116 are curved in both the YZ and XZ planes. The upper section 112 of the coupling transition 110 has a trapezoidal shape with a slight curvature but is flatter than the side walls 116. The lower section 113 of the coupling transition 110 is the narrowest part of the coupling transition 110 and remains relatively narrow throughout.

[0018] The bell 120 comprises a first bottom section 121 and a second bottom section 122. The first bottom section 121 is trapezoidal and leads to the second bottom section 122, which is also trapezoidal. The bell 120 also comprises an upper section 123, which is trapezoidal. In addition, the bell 120 comprises two side walls 124. Due to the curved design of the slot 111 with variable width at the end 115 of the coupling transition 110, the first bottom section 121 is partially overlapped by the upper section of the coupling transition 110. The second bottom section 122, on the other hand, is arranged around an outer surface of the coupling transition 110, similar to the two side walls 124 and the upper section 123.

[0019] Fig. 1D shows a perspective side view 100D of the loudspeaker. Fig. 1A according to exemplary embodiments. With reference to Fig. 1D allows a driver 150 to emit sound towards the throat 130 of the horn. In this case, the sound can enter through the throat and exit through the coupling transition 110 and the bell 120. In this example, the differences in the area of ​​the variable-width slot between the beginning 114 and the end 115 of the coupling transition 110 are shown.

[0020] In particular, a first region 110a of the coupling transition 110, corresponding to the beginning 114 of the coupling transition 110, is shown in two dimensions (YZ plane). Furthermore, a second region 110b of the coupling transition 110 is shown in the same two dimensions (YZ plane) at the end 115 of the coupling transition 110. That is, while the side view 100D of the coupling transition 110 is shown in two dimensions of the XY plane, the surface views of the first region 110a and the second region 110b are shown in the two dimensions of the YZ plane.

[0021] As in Fig. As can be seen in 1D, the shape of the coupling transition 110 changes in both height and width. In particular, the height increases from the first region 110a to the second region 110b, while the width tapers at the lower section of the coupling transition 110 from the first region 110a to the second region 110b. This is due to the curved surfaces along the side walls 116 (in Fig. (1C shown) of the coupling transition 110, which curves in each of the three dimensions (YZ and XZ planes) and thus creates the different shapes of the coupling transition 110. The three-dimensional curvature simultaneously results in a stronger limitation of the sound pressure level in the lower section of the coupling transition 110 and increases / enables a higher sound pressure level in the upper section of the coupling transition 110, thereby allowing more sound to be emitted from the upper section of the variable-width slot 111.

[0022] For example, the width in the Z-direction of the first region 110a of the coupling transition 110 can be greater than the width in the Z-direction of the second region 110b of the coupling transition 110. For example, the width of the first region 110a can be twice as wide, three times as wide, or even wider, or have any other desired difference in width compared to the width of the second region 110b. Meanwhile, the height of the first region 110a of the coupling transition 110 is smaller than the height of the second region 110b of the coupling transition 110. For example, the height of the first region 110a can be half the height of the second region 110b, two-thirds the height of the second region 110b, or any other desired difference in height.

[0023] Fig. Figure 1E shows a perspective top view of the loudspeaker (Figure 100E). Fig. 1A according to exemplary embodiments. With reference to Fig. In Figure 1E, the loudspeaker is viewed from above. Here, the upper section 123 of the bell 120 and the upper section 112 of the coupling transition 110 are visible. The neck 130 is also shown at the bottom of the drawing. As can be seen from this view, the upper section 123 of the bell 120 is trapezoidal and has a width that tapers towards the coupling transition 110. Similarly, the upper section 112 of the coupling transition 110 is also trapezoidal with a width that tapers towards the neck 130 of the loudspeaker assembly.

[0024] Fig. Figure 1F shows a perspective bottom view of the loudspeaker 100F. Fig. 1A according to exemplary embodiments. With reference to Fig. In section 1F, the loudspeaker is viewed from below. Here, the second bottom section 122 of the bell 120 has a trapezoidal shape that tapers towards the first bottom surface 121. The first bottom section 121 has a trapezoidal shape that appears almost triangular and terminates at the lower section 113 of the coupling transition 110. Furthermore, the lower section 113 of the coupling transition 110 has an approximately linear shape and is the point where the side walls 116 of the coupling transition 110 converge and almost touch.

[0025] Fig. 1G shows a skewed perspective view 100G of the loudspeaker from Fig. 1A according to further embodiments. With reference to Fig. Figure 1G shows a rear view of the loudspeaker arrangement, which provides an understanding of the curved nature of the side walls 116 of the coupling transition 110 and the curved nature of the side walls 124 of the bell 120. In this example, both the side walls 116 and the side walls 124 are curved / flared in each of the three dimensions. Here, the lower section 113 of the coupling transition 110 compresses the side walls 116, thereby forcing the sound pressure upwards towards the upper section 112 of the coupling transition 110 as the sound travels from the throat 130 through the coupling transition 110 and towards the bell 120. In addition, the first lower section 121 and the second lower section 122 of the bell 120 are widened from the coupling transition 110 outwards in the direction of the mouthpiece 140 in the bell 120, where the sound is emitted.

[0026] Fig. Figure 2 shows an example of a sound coverage area 212 of a loudspeaker 210 according to the exemplary embodiments. A conventional horn with constant directivity produces a sound coverage area that is more fan-shaped or trapezoidal. In the exemplary embodiments, the horn with constant coverage described here can produce a more rectangular coverage area. With reference to Fig. 2. The loudspeaker 210 can have a horn like in the Fig. The components shown and described in 1A-1G include a driver for generating sound. The horn can produce a coverage or radiation area suitable for a rectangular listening area 220, as shown. The sound radiation area 212 represents the SPL of the emitted sound. In this example, the sound radiation area 212 extends to one end of the rectangular listening area, thus providing relatively constant SPL coverage for listeners both closest to and furthest from the loudspeaker 210.

[0027] Although the coverage area in Fig. 2. If the shape is more rectangular, the horn can be designed to allow for a differently shaped coverage area.

[0028] Furthermore, the examples in the Fig.1A-1G and 2 refer to the horn with a rectangular mouthpiece (i.e., with a height greater than its width); however, it should also be noted that the mouthpiece can be square. As another example, the mouthpiece can be rectangular where the height is less than the width, and so on.

[0029] It goes without saying that the components of the invention, as generally described here and illustrated in the figures, can be arranged and designed in a multitude of different configurations. The detailed description of the embodiments is therefore not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0030] A person skilled in the art will readily understand that the above can be carried out with steps in a different sequence and / or with hardware elements in configurations that differ from those disclosed. Although the invention has been described on the basis of these preferred embodiments, it would be obvious to those skilled in the art that certain modifications, variations, and alternative designs are possible.

[0031] Although preferred embodiments of the present invention have been described, it is to be understood that the described embodiments are only illustrative and the scope of the invention is defined exclusively by the attached claims when considered with a full range of equivalents and modifications (e.g. protocols, hardware devices, software platforms, etc.).

Claims

[1] Horn, having: a neck that has an opening to receive sound; a bell that directs the sound; a mouthpiece opening that emits the sound; and a variable-width slot arranged between the neck and the bell that directs the sound, the variable-width slot having a lower section with a first width and an upper section with a second width which is greater than the first width. [2] Horn according to claim 1, wherein the slot with variable width has a curved shape from the lower section to the upper section. [3] Horn according to claim 1, wherein the slot with variable width has a V-shape. [4] Horn according to claim 1, wherein the slot with variable width has a pie-slice shape. [5] Horn according to claim 1, wherein the variable-width slot in the upper section has a lower acoustic resistance compared to the lower section. [6] Horn according to claim 1, wherein the mouthpiece has a rectangular opening comprising an upper section with a first width, a lower section with a second width and sides between the upper section and the lower section having a vertical height, wherein the vertical height is greater than the first width and the second width. [7] Horn according to claim 1, wherein the mouthpiece has a rectangular opening comprising an upper section with a first width, a lower section with a second width and sides between the upper section and the lower section having a vertical height, the vertical height being less than the first width and the second width. [8] Horn according to claim 1, wherein the mouthpiece has a square opening comprising an upper section with a first width, a lower section with a second width and sides between the upper section and the lower section having a vertical height, the vertical height being approximately equal to the first width and the second width. [9] Horn according to claim 1, wherein a horizontal coverage area of ​​the horn depends on the relative position of the horizontal coverage within the area of ​​the vertical coverage of the horn. [10] Loudspeakers, comprising: a neck that has an opening to receive sound; a bell that directs the sound; a mouthpiece opening that emits the sound; a sound source positioned behind the opening of the throat and configured to emit sound towards the opening of the throat; and a variable-width slot arranged between the neck and the bell that directs the sound, the variable-width slot having a lower section with a first width and an upper section with a second width which is greater than the first width. [11] Loudspeaker according to claim 10, wherein the slot with variable width has a curved shape from the lower section to the upper section. [12] Loudspeaker according to claim 10, wherein the slot with variable width has a V-shape. [13] Loudspeaker according to claim 10, wherein the slot with variable width has a pie-slice shape. [14] Loudspeaker according to claim 10, wherein the variable-width slot in the upper section has a lower acoustic resistance compared to the lower section. [15] Loudspeaker according to claim 10, wherein the mouthpiece has a rectangular opening comprising an upper section with a first width, a lower section with a second width and sides between the upper section and the lower section having a vertical height, wherein the vertical height is greater than the first width and the second width. [16] Loudspeaker according to claim 10, wherein the mouthpiece has a rectangular opening comprising an upper section with a first width, a lower section with a second width and sides between the upper section and the lower section having a vertical height, the vertical height being less than the first width and the second width. [17] Loudspeaker according to claim 10, wherein the mouthpiece has a square opening comprising an upper section with a first width, a lower section with a second width and sides between the upper section and the lower section having a vertical height, wherein the vertical height is approximately equal to the first width and the second width. [18] Loudspeaker according to claim 8, wherein a horizontal coverage area of ​​the loudspeaker depends on the relative position of the horizontal coverage within the area of ​​the vertical coverage of the horn.

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