JP7310970B2 - speaker - Google Patents

Description

The present invention relates to a loudspeaker, and more particularly to a loudspeaker with a diffuser.

In a cone-shaped diaphragm attached with a center cap that protrudes forward at the center, the periphery of the center cap and its vicinity form an annular depression.
When a speaker equipped with this diaphragm is operated, the output sound from the center cap and the output sound from the diaphragm interfere with each other in the space immediately in front of the recess, causing peaks and dips at specific frequencies, and the sound pressure frequency It is known that a so-called prechamber effect (cavity effect), which disturbs the characteristics, occurs. This anterior chamber effect should be suppressed, and an example of a suppression technique is described in US Pat.
On the other hand, in a speaker provided with a diaphragm to which the above-mentioned center cap is attached, there is known a technique of arranging a diffuser for adjusting the directional characteristics of the output sound in front of the center cap, which is described in Patent Document 2. It is

JP 2004-343804 A JP 2011-010056 A

Since the diffuser of the speaker described in Patent Document 2 has limitations in adjusting the directional characteristics, an improvement has been desired.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a loudspeaker capable of satisfactorily adjusting directional characteristics.

In order to solve the above problems, the present invention has the following configurations.
A vibrating body and a diffuser positioned so that the end on the vibrating body side faces the vibrating body, and the end on the vibrating body side has a gouged part in which the distance from the vibrating body changes smoothly in the circumferential direction. .

ADVANTAGE OF THE INVENTION According to this invention, the effect that directivity characteristic adjustment can be performed favorably is acquired.

FIG. 1 is a perspective view of a coaxial speaker 53 with a tweeter 51, which is an example of a speaker according to an embodiment of the invention. FIG. 2 is a cross-sectional view taken along line S2-S2 in FIG. FIG. 3 is a front perspective view of the diffuser base 8 provided in the tweeter 51. FIG. FIG. 4 is a perspective view of the rear side of the diffuser base 8. FIG. FIG. 5 is a graph for explaining the circumferential height of the bottom end portion 9c of the diffuser 9 of the diffuser base 8. As shown in FIG. FIG. 6 is a graph for explaining the difference in directional characteristics depending on whether the diffuser 9 is present or not. FIG. 7 is a graph for explaining the difference in sound pressure frequency characteristics depending on the presence or absence of the gouged portion E. FIG. FIG. 8 is a front view showing a speaker system 61 as an example of the speaker system according to the embodiment of the invention. FIG. 9 is a front view showing a stereo speaker system 62, which is an example of the stereo speaker system according to the embodiment of the invention. FIG. 10 is a schematic top view showing the vicinity of the driver's seat of an automobile. FIG. 11 is a schematic front view showing an in-vehicle stereo speaker system 51BS, which is an example of the in-vehicle stereo speaker system according to the embodiment of the present invention. 12A and 12B are graphs for explaining a modification of the gouged portion E. FIG.

A speaker according to an embodiment of the present invention will be described using a tweeter 51, which is a speaker of an embodiment.

(Example 1: Tweeter 51)
FIG. 1 is a perspective view showing a coaxial speaker 53 equipped with a tweeter 51. FIG. The coaxial speaker 53 is a so-called coaxial two-way speaker having a woofer 52 and a tweeter 51 coaxially attached to the woofer 52 .
The woofer 52 has a frame 52a and a conical diaphragm 52c supported by the frame 52a via an edge 52b. Here, the cone shape means a shape such as a truncated cone shape or a shape such as a petal shape of a morning glory that expands continuously from the root side to the tip side.
For the convenience of the following description, the front-rear direction is defined along the axis CL53 of the coaxial speaker 53, as shown in FIG.
In the coaxial speaker 53, the axis CL52 of the woofer 52 and the axis CL51 of the tweeter coincide with the axis CL53.

FIG. 2 is a vertical cross-sectional view of the tweeter 51, taken along line S2-S2 in FIG. The tweeter 51 is a so-called dynamic speaker.
The tweeter 51 has a body frame 1 and a magnetic circuit M including a yoke 2 , magnets 3 and a top plate 4 .

The main body frame 1 has a central hole 1a and has a substantially annular shape, and is fixed to a post 52d projecting forward from the central portion of the woofer 52. As shown in FIG.
The yoke 2 has the shape of a pot, and is attached to the body frame 1 by engaging the outer peripheral portion of the peripheral wall with the central hole 1a of the body frame 1 .
The magnet 3 is disk-shaped and fixed to the front surface of the bottom wall so as to form a predetermined radial gap with the peripheral wall of the yoke 2 .
The top plate 4 is disc-shaped and attached to the front surface of the magnet 3 .

The body frame 1 supports a cone-shaped or morning glory petal-shaped diaphragm 6 via an edge 6a so as to be movable back and forth.
The diaphragm 6 has a fitting portion 6b in the center. A center cap 7 in the form of a spherical shell projecting forward is attached to the diaphragm 6 so as to close the fitting portion 6b, forming a so-called balance dome shape. The diaphragm 6 and the center cap 7 emit sound by vibrating. Further, when the center cap 7 is convex forward, the center cap 7 and the diaphragm 6 form an annular valley portion Qa. In other words, the diaphragm 6 and the center cap 7 sandwich the valley portion Qa to form a vibrating body 67 for emitting sound. The center cap 7 may have an integral structure with the diaphragm 6 . Also, the center cap 7 may be adhered to the voice coil bobbin 5 and may have a distance from the diaphragm 6 . The center cap 7 is not limited to being convex forward, and may be convex rearward.
A front end portion of a cylindrical voice coil bobbin 5 is inserted into the fitting portion 6b of the diaphragm 6 and attached so as to extend rearward. A voice coil 5 a is wound around the rear end of the voice coil bobbin 5 .
A voice coil bobbin 5 around which a voice coil 5a is wound is disposed in a radial gap between the magnet 3 and the top plate 4 and the yoke 2 so as to be movable back and forth.
When a voice signal is supplied to the voice coil, the voice coil bobbin 5 and the diaphragm 6 to which it is attached vibrate back and forth due to electromagnetic induction with the magnetic circuit M to output sound.

The inner peripheral edge of the fitting portion 6b of the diaphragm 6, that is, the outer peripheral edge of the center cap 7 and the position of the front end portion of the voice coil bobbin 5, in the balance dome vibrating body 67 combining the diaphragm 6 and the center cap 7, are: It is an annular valley portion Qa corresponding to the bottom of a portion recessed to the rear side, which is also called a neck.

The tweeter 51 has a diffuser base 8 on the front side. The diffuser base 8 is attached to the front surface of the body frame 1 in this example. The diffuser base 8 is made of resin, for example.
3 is a perspective view of the diffuser base 8 seen obliquely from the front, and FIG. 4 is a perspective view of the diffuser base 8 seen obliquely from the rear.
As shown in FIGS. 2 to 4, the diffuser base 8 has a substantially annular plate shape, and is arranged in the sound emitting hole 8a having an inner diameter D8b larger than the outer diameter D5b of the diaphragm 6 and the sound emitting hole 8a. , and a diffuser 9 connected and supported by a support arm 10 to the inner peripheral portion of the sound emitting hole 8a. Further, the diffuser base 8 has an outer peripheral end 8b that is folded back to form a flange, and the sound emitting hole 8a to the outer peripheral end 8b are connected by a slope. Here, the slope may be straight in vertical cross section, or may have a curvature.
In this example, three support arms 10 are provided at a pitch of 120° around the axis CL51.

The diffuser 9 has a disk-shaped front end portion 9d having a central hole 9a centered on the axis CL91, and a base portion 9b formed in an umbrella-like shape extending rearward from the periphery of the front end portion 9d. . Here, the diffuser 9 may be composed only of the base portion 9b and may not have the front end portion 9d, and the front end portion 9d may not have a flat disc shape. The base portion 9b may be cylindrical without widening.
The axis CL9 (see FIG. 3) of the central hole 9a coincides with the axis CL51 of the tweeter 51 when the diffuser 9 is attached to the body frame 1. As shown in FIG.
Note that the axis CL9 of the central hole 9a and the axis CL51 of the tweeter 51 do not have to coincide. If they do not match, the distance from an arbitrary point on the axis CL51 to the ridgeline of the central hole 9a changes around the axis CL51. The effect of smoothing peaks and dips is obtained.
The inner surface 9b1 of the base portion 9b has a corner portion between the disk-shaped front end portion 9d and the umbrella-shaped base portion 9b, and has a space between the center cap 7 formed in an arc shape. configured to It may be formed as a curved surface generally along the center cap 7 . Further, when the base portion 9b does not have an umbrella-like spread and is cylindrical, the inner surface 9b1 becomes a surface substantially parallel to the axis CL91. The outer surface 9b2 is formed as a curved surface that is set to have substantially the same plate thickness as the inner surface 9b1.
The diffuser 9 may not be a continuous closed ring around the axis CL91, but may be a discontinuous substantially ring with a slit in part. Moreover, it may be formed in an arc shape including a C shape having a large opening in the circumferential direction. In the following description, it will be described as a closed ring.

The base portion 9b is formed so that the radial position of the bottom end portion 9c, which is the rear side end portion (rear end portion) thereof, is located in front of the annular valley portion Qa at a position corresponding thereto. Further, in the front-rear direction, at least the rear end side of the base portion 9b is positioned within the front space Va of the annular valley portion Qa.
When the front space Va is defined as a reference plane LNb, which includes the rearward (lower) portion of the outer periphery of the diaphragm 6 and the vertex of the center cap 7 and is perpendicular to the axis CL51. 2, the space is defined as a space on the front side of the diaphragm 6 and the center cap 7 and on the rear side of the reference plane LNb. In FIG. 2 , the reference plane LNb is indicated by a dashed line, and the cross section of the front space Va is shown in the area between the reference plane LNb and the vibrating body 67 .
A portion of the base portion 9b of the diffuser 9 enters the rear side of the reference plane LNb. That is, it is in the forward space Va.

Further, the bottom end portion 9c, which is the rear end portion of the base portion 9b, does not have the entire circumference included in the same plane, but has a gouged portion E that is partially gouged forward.
In this example, as shown in FIGS. 3 and 4, the gouged portions E are formed at three locations as recesses 9c1 to 9c3.

For easy understanding, description will be made with reference to FIG. 5 as well.
FIG. 5 is a plan view of the front-rear position of the bottom end portion 9c developed over a 360° circumference with the circumferential position Pa in FIG. 3 being 0°. The circumferential position Pa is a position other than the gouged portion E. As shown in FIG. That is, the horizontal axis is the circumferential position around the axis CL9 with the circumferential position Pa as the base point, and the vertical axis is the bottom end 9c at the circumferential position Pa as the reference height LNa (see FIG. 2). is the gouging height H, which is the recessed amount of the . As shown in FIG. 5, the gouge height H of the concave portions 9c1 to 9c3 is Ha at maximum.
It means that the larger the gouging height H on the vertical axis, the stronger the gouging degree. If the gouge height H exceeds the axial width of the base portion 9b, the base portion 9b is divided to form a slit. When there are a plurality of slits formed by the gouged portion E, the support arm 10 is arranged so as to support a plurality of base portions 9b divided by the slits.
Further, at the gouged portion E, the gouged width W is defined as the circumferential distance at which the gouged height H becomes a positive value.

In the tweeter 51 described above, the diffuser 9 has its bottom end 9c entering the front space Va and is arranged close to the annular valley Qa.
As a result, the base portion 9b of the diffuser 9 functions as a separation wall that divides the front space Va into the center cap 7 side and the cone-shaped diaphragm 6 side.
Therefore, by suppressing the interference between the output sound from the center cap 7 and the output sound from the cone-shaped portion of the diaphragm 6, occurrence of peaks and dips at specific frequencies is reduced, and the sound pressure of the output sound is reduced. Disturbances in frequency characteristics are less likely to occur. That is, the anterior chamber effect is suppressed.

However, if the diffuser 9 does not have the gouged portion E, the diffuser 9 also operates as an acoustic tube and has a single resonance frequency because the height of the base portion 9b in the front-rear direction is uniform. As a result, the output sound is emphasized in a specific frequency range, generating peaks and disturbing the frequency characteristics.
Therefore, by providing one or a plurality of gouged portions E in the diffuser 9, the resonance frequency caused by the height and diameter of the cylindrical base portion 9b in the front-rear direction is dispersed, and the peak of the output sound can be suppressed. In the case of having a plurality of gouged portions E, the resonance frequency of the cylindrical base portion 9b is dispersed, so that the directional characteristics are improved.

When the gouged portion E is rectangular, the base portion 9b has two heights, the gouged portion E and the height other than the gouged portion E. Therefore, there are only two resonance frequencies, and the frequency characteristic has two peaks. For this reason, it is preferable that the shape of the gouged portion E be a shape such as a sine wave, a triangular wave, or an arc, which further disperses the resonance frequency. Further, it is more preferable that points other than the gouged portion E are not uniform in the height direction. Note that in the sound pressure frequency characteristics of the tweeter 51, if the peak or dip frequencies in question are related to these two resonance frequencies, this is not the only case.
The arrangement of the gouged portion E is not limited to the rear end portion of the diffuser 9, and may be the front end portion. The resonance frequency due to the sound tube effect can be dispersed in the same manner as in the case of being arranged at the rear end, and the effect as a protective wall to prevent interference between the output sound of the center cap 7 and the diaphragm 6 is the valley Qa and the diaphragm 6. Since the distance of is short, more effects can be obtained.

Furthermore, regarding the degree of proximity between the diffuser 9 and the annular valley Qa, the distance between the portion of the bottom end 9c without the gouged portion E and the annular valley Qa in the front-rear direction is the maximum rated amplitude of the tweeter 51 for the audio signal. It is set to be the minimum within the range that does not interfere with the amplitude of the diaphragm when is input. As a result, the function of the base portion 9b as a separation wall is maximized, and the front chamber effect is further suppressed.

In this way, the tweeter 51 has the diffuser 9, so that the interference between the output sound from the center cap 7 and the output sound from the cone-shaped portion of the diaphragm 6 can be suppressed satisfactorily. This interference suppression reduces the loss of energy due to the cancellation of output sounds having angles different from the direction of the sound emission axis, so that the sound pressure of the output sound increases in all directions and the directional characteristics of the output sound become wider. More specifically, the sound pressure increases not only in the plane perpendicular to the axis CL51 but also in the solid angle range in the direction from the axis CL51 to the gouged portion E, thereby widening the directivity.

FIG. 6 is a graph for explaining the difference in directional characteristics depending on the presence or absence of the diffuser 9, for example, the characteristics at 14.5 kHz when the outer circumference of the diaphragm 6 is about 25 mm.
In FIG. 6, the solid line indicates the directional characteristics of the tweeter 51, that is, the directional characteristics when the diffuser 9 is provided, and the dashed line indicates the directional characteristics of the speaker when the diffuser 9 is not provided. The front of the axis CL51, which is the front, is 0°.

As shown in FIG. 6, the directivity characteristic is widened by attaching the diffuser 9, and the improvement of the directivity characteristic is particularly remarkable in a region wider than 40°.
This result is obtained with a similar tendency at 14 kHz to 20 kHz.

Here, the state of interference between the sound from the center cap 7 and the sound from the cone-shaped diaphragm 6 differs between the angular range in which the gouged portion E near the diffuser 9 is arranged and the angular range in which it is not arranged. The state of interference changes around CL9. Accordingly, the diffuser 9 has the gouged portion E in the bottom end portion 9c, so that the degree of interference of the sound emitted from the tweeter 51 reaching the axis CL9 can be adjusted. As a result, the directional characteristics of the output sound of the tweeter 51 can be adjusted according to the position, number, and shape of the gouged portions E provided. Also, peaks and dips in the sound pressure frequency characteristics in the axis line CL51 of the tweeter 51 can be suppressed. Since the distance from an arbitrary point on the axis CL51 to the ridgeline of the central hole 9a changes around the axis CL51, sound with different paths arrives on the axis, smoothing peaks and dips in the sound pressure frequency characteristics. You can get the effect of

FIG. 7 shows the sound pressure frequency characteristics of 10 kHz to 20 kHz in front of the front axis CL53 depending on the presence or absence of the gouged portion E. FIG.
The solid line shows the characteristics of the tweeter 51 with the gouged portion E, and the dashed line shows the characteristics when the diffuser 9 of the tweeter 51 is replaced with a diffuser without the gouged portion E in the shape of the base portion 9b.

As shown in FIG. 7, by providing the gouged portion E, it is possible to improve the sound pressure particularly in the high frequency range of 16 kHz or higher.
This is because the interference between the sound emitted from the center cap 7 and the sound emitted from the diaphragm 6 in the vicinity of the diffuser 9 is suppressed by the base portion 9b of the diffuser 9, thereby suppressing the front chamber effect. , the sound pressure in the high range from the center cap 7 increases.

(Embodiment 2: speaker system 61)
In general, when listening to the output sound from the front (front) side of a speaker system in which the speaker is attached to the enclosure, the directional characteristics of the high frequency range are such that if the directivity is wide in the upper side (parietal side), the listening sound field will be upward. Widening is known to be good, especially in listening to music.
Therefore, it is preferable to use a speaker having a diffuser 9 in the speaker system and attach the speaker to the enclosure so that the gouged portion E faces the upper side (top side) in use.

FIG. 8 is a front view (front view) showing a speaker system 61 as an example thereof. The speaker system 61 is a so-called two-way speaker having an enclosure 61a, which is an acoustic box, and a woofer 61b and a tweeter 51A attached to the enclosure 61a.
The tweeter 51A has the same structure as the tweeter 51, and is attached to the enclosure 61a so that one of the gouged portions E of the diffuser 9 faces upward (indicated by an arrow) in the usage posture.

The loudspeaker system 61 has a higher sound pressure in the upper direction at least in the high range of the output sound, and the directional characteristics are richer in the upper direction.
As a result, a listener who listens to the output sound from the front (front) can feel a good sound field with a clear sound image and spatial spread due to the sound image being localized upward.

(Example 3: Stereo speaker system)
For reproducing stereo sound, a pair of the speaker systems 61 of the second embodiment can be paired to form a stereo speaker system.
Also, one enclosure may be provided with a pair of speakers to form a stereo speaker system.
FIG. 9 is a front view showing an example stereo speaker system 62. As shown in FIG.
The stereo speaker system 62 includes a pair of left and right speakers 51A in an enclosure 62a. In each speaker 51A, one of the gouged parts E of the diffuser 9 is
The installation posture with respect to the enclosure 62a is determined such that the stereo speaker system 62 is positioned upward (indicated by an arrow) when used.
In these stereo speaker systems, the listener can feel a three-dimensionally spread stereo sound field due to the higher sound pressure in the upper sound range.

(Embodiment 4: In-vehicle stereo speaker system)
A stereo speaker system, which is a set of speakers whose directional characteristics are adjusted by the formation position of the gouged portion E, is also useful for in-vehicle use. This will be described with reference to FIGS. 10 and 11. FIG.
FIG. 10 is a schematic top view showing the vicinity of the driver's seat of an automobile.
FIG. 11 is a diagram illustrating a vehicle-mounted stereo speaker system 51BS.

A vehicle-mounted stereo speaker system 51BS is configured as a set of a left speaker 51BL and a right speaker 51BR. The speakers 51BL and 51BR may be tweeters, and may be a separate speaker system combined with a woofer.
The speaker 51BL and the speaker 51BR differ only in the circumferential position of the gouged portion E, and otherwise have the same structure.
An example of the installation mode of the speakers 51BL and 51BR in which the driver D in the vehicle can obtain the effect of expanding the directivity by the gouged portion E is as follows. Of course, the installation mode is not limited to the following example.
When the body axis of the driver (parallel to the vertical axis of the vehicle) is the A axis, the axis perpendicular to the A axis and passing through the height of driver D's ear is the B axis, and the axis perpendicular to the B axis is the C axis. To. In order to turn the gouged portion E of the speaker 51BL or 51BR toward the ear of the driver D in the vehicle interior, the sound emission axis of the speaker 51BL or 51BR is defined as the C axis. For example, when the speaker 51BL or the speaker 51BR is arranged vertically upward on the dashboard of the vehicle, the direction of sound emission is parallel to the A axis. Here, if the B-axis perpendicular to the A-axis is the longitudinal direction of the vehicle, the C-axis perpendicular to the B-axis is the vertical axis of the vehicle and coincides with the sound emission axis. In this relationship, by directing the gouged portion E of the speaker 51BL or 51BR toward the ear of the driver D, the effect of expanding directivity is obtained.
As described above, the effect of the gouged portion E spreads the directivity to the solid angle in the direction of the gouged portion E. Therefore, even when the height of the speaker 51BL or 51BR is different from the height of the ears of the driver D, the sound image You can get a sense of expansiveness.
As shown in FIGS. 10 and 11, in the vehicle, the left speaker 51BL mounted upward on the mounted member on the left side of the driver D (the left side of the dashboard DB in this example) outputs sound that A gouged portion E is provided at an angle θLa corresponding to the angle θL toward the left ear De1 of the person D, and is adjusted to increase the sound pressure of high frequencies in the direction of the angle θLa.
On the other hand, the right speaker 51BR, which is mounted facing upward on the right mounting member for the driver D (the right side of the dashboard DB in this example), corresponds to the angle θR toward the right ear De2 of the driver D, who is the listener. A gouged portion E is provided at an angle θRa, and is adjusted to increase the sound pressure of high-pitched sounds in the direction of the angle θRa.
In the case of a right-hand drive vehicle, the angles θL and θLa are smaller than the angles θR and θRa. The opposite is true for left-hand drive vehicles.

The left speaker 51BL is provided with a gouged portion E at a position offset by an angle θLa in the counterclockwise direction with respect to the rear of the installation posture when viewed from above. Further, the right speaker 51BR is provided with a gouged portion E at a position shifted by an angle θRa in the clockwise direction with respect to the rear of the installation posture when viewed from above.
As a result, the left and right speakers 51BL and 51BR output sounds whose output sound pressure mainly in the high range is adjusted by the gouged portion E so as to target the left ear De1 and right ear De2 of the driver D, respectively.
Therefore, even though the driver D sits in a position that is biased to the left and right, the driver D can hear a good three-dimensional sound image with a well-balanced high frequency range on the left and right sides. If the diffuser 9 has, for example, three hollowed out portions E as in the first embodiment, in addition to the hollowed out portion E facing the user, the sound emitted from the other hollowed out portions E gives a sense of depth to the output sound. effective.

The members to which the speakers 51BL and 51BR are mounted in the vehicle include, for example, the dashboard DB, doors, window pillars, ceilings, and the like.

The embodiments described in detail above are not limited to the configurations described above, and modifications may be made without departing from the gist of the present invention.

Each of the plurality of gouged portions E may have its own gouged height H, gouged width W, and gouged shape. Representative examples of this are shown in FIGS.

FIG. 12(a) is an example in which each of a plurality of gouged portions E is formed in a triangular shape. Although the gouge heights H are equal to each other with the height Ha, they may of course be different.
Further, the deformed shape of the gouged portion E is not limited to a triangular shape, and may be, for example, a sine wave shape. In the case of a sine wave, the sound pressure characteristics in the circumferential direction transition smoothly, and changes in the sound pressure characteristics in the circumferential direction at equal radial distances from the axis CL91, which is the sound emission axis, are audibly smooth.
Further, the shape of the gouged portion E may be rectangular, in which case the sound pressure characteristics in the circumferential direction can be changed sharply.

FIG. 12(b) shows an example in which a plurality of gouged portions E are continuously formed. In this example, the portion where the gouge height H is 0 (zero) is not linear but dotted in the figure. Of course, it may be partially linear.
FIG. 13(c) shows an example in which the gouged height H, gouged width W, and gouged shape of each of the plurality of gouged portions E are all different. Of course, not all but only a part may be different.
The shapes and the like illustrated in FIGS. 12(a) to 12(c) can be freely combined.

Also, the front end portion 9d, which is the upper end of the diffuser 9, may have a gouged portion that is not flat but is gouged rearward.
Even if the front end portion 9d is provided with a gouged portion, the degree of interference between the output sound from the diaphragm 6 and the output sound from the center cap 7 can be adjusted to some extent. A peak dip on the axis CL51, which is the sound axis, can be suppressed.

The base portion 9b of the diffuser 9 has a corner portion between the above-described umbrella-shaped base portion 9b and the disc-shaped front end portion 9d, and a space is provided between the center cap 7 and the arc-shaped center cap 7, thereby increasing the output of the center cap 7. The pressure applied to the vibration of the center cap 7 can be reduced while imparting a diffusion effect to the sound. Since no pressure is applied to the vibration and the vibration is not suppressed, the sound pressure of the output sound from the center cap 7 is not suppressed and is emitted forward from the central hole 9a, so that the output sound pressure can be increased.
Depending on the output sound quality of the tweeter 91, the shape of the base portion 9b is not limited to an umbrella shape covering the outer peripheral side of the center cap 7, but may be, for example, a cylindrical shape with the same diameter or a cone shape expanding forward. .

The number and circumferential positions of the support arms 10 connecting the diffuser base 8 and the diffuser 9 are not limited to three at a pitch of 120° as described above, but can be set according to specifications such as the usage environment and the sound field to be set. good.
Although the cone shape of the diaphragm 6 of the tweeter 91 has been described as a circular cone shape, it is not limited to a circular shape. It may be elliptical.
In addition, the diffuser 9 is not limited to being mounted on a tweeter for a high range, and can be mounted on a speaker such as a squawker, a woofer, or a full-range speaker to suppress the front chamber effect and the directional characteristics of the output sound. can be adjusted.

Although a cone-shaped diaphragm (including a morning glory petal-shaped diaphragm) has been described as the diaphragm 6, it is not limited to this.
As long as the vibrating body 67 has an annular trough Qa and produces an anterior chamber effect, it can be applied because the effect of the diffuser 9 is exhibited.

1 body frame 1a center hole 2 yoke 3 magnet 4 top plate 5 voice coil bobbin 5a voice coil 5b outer diameter 6 diaphragm 6a edge 6b fitting portion 7 center cap 8 diffuser base 8a sound emission hole 8b outer periphery End 9 diffuser 9a center hole 9b base 9b1 inner surface 9b2 outer surface 9c bottom end 9c1 to 9c3 recess 9d front end 10 supporting arms 51, 51A tweeter (speaker)
51BL, 51BR (vehicle use) speaker 51BS (vehicle use) stereo speaker system 52 woofer (speaker)
52a Frame 52b Edge 52c Diaphragm 52d Support 53 Coaxial speaker 61 Speaker system 61a Enclosure 61b Woofer 62 Stereo speaker system 62a Enclosure 67 Vibrating body CL51, CL52, CL53, CL9 Axis D Driver De1 Left ear De2 Right ear D5b Outer diameter D8b Inner diameter E Gouged portion H Gouged height Ha Height M Magnetic circuit LNa Reference height LNb Reference plane Pa Circumferential position Qa Annular valleys TL, TR Door Va Front space W Gouged width θL θR, θLa, θRa Angle

Claims (2)

a vibrating body;
a diffuser positioned so that the end on the vibrating body side faces the vibrating body,
A speaker, wherein the end on the vibrating body side has a gouged part in which the distance from the vibrating body changes smoothly in the circumferential direction. a vibrating body;
a diffuser having an annular base, wherein the end of the base on the vibrating body side is positioned to face the vibrating body;
The end on the vibrating body side has a gouged part having a sine wave shape, an arc shape, or a triangular wave shape, the distance from the vibrating body being greater than that of the other part.

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