JP2020178147A - Ceiling embedded speaker - Google Patents

Abstract

To provide a ceiling embedded speaker that has wide directivity even when a cabinet is installed so as to be embedded in a ceiling, and in which a difference in sound pressure level between the position directly under an embedded speaker and the position away from the speaker is reduced.SOLUTION: A ceiling embedded speaker 1 includes a cabinet 10 and at least two speaker units 21 to 25, and the cabinet includes a flat surface portion 11 including a flat surface defined on the upper side deeper than the ceiling surface, a side wall portion 16 that defines an annular side wall surface that connects the flat surface and the ceiling surface, and a mounting portion 12 that mounts the speaker unit so as to protrude downward from the flat surface on the outer peripheral side of the flat surface portion and so as not to protrude downward from the side wall portion. Each of the speaker units is mounted on the mounting portion so as to be tilted such that the diaphragm approaches the side wall, and connection of two identical speaker units arranged next to each other emit sound waves in an opposite phase relationship is performed.SELECTED DRAWING: Figure 1

Description

The present invention relates to a ceiling-embedded speaker, and in particular, the directivity is widened even when the cabinet is embedded in the ceiling, and the sound pressure level difference between the position directly under the embedded speaker and the position away from the speaker is large. Regarding less ceiling-embedded speakers.

Ceiling-embedded speakers installed on the ceiling inside a building are used for loudspeakers that transmit voice such as announcements and music to people in the room. When the ceiling-embedded speakers are installed indoors in a large store or in a long corridor, a plurality of speakers may be connected so as to reproduce the same sound and arranged at appropriate installation intervals.

However, if the direct radiation type speaker is installed so as to be simply embedded in the ceiling, there is a problem that the sound pressure level difference tends to be large in the room because the directivity is narrow. In such a case, the sound pressure level on the right side in the front direction on the axis where the diaphragm vibrates becomes high, while the sound pressure level becomes high at a position other than the front direction on the axis, that is, a position away from the speaker. This is because it tends to be low. The directivity of the direct radiation type speaker is strong toward the front side and tends to be narrowed in the high frequency range where the wavelength of the sound wave radiated from the diaphragm is short. As a result, there is a problem that the sound reproduced in the room is noisy and hard to hear.

Therefore, each ceiling-embedded speaker is required to have a wide directivity. If the directivity is wide, it is expected that the difference in sound pressure level of the sound reproduced in the room will be small even with one ceiling-embedded speaker. Further, if the directivity is wide, even when a plurality of ceiling-embedded speakers are installed, the number of installed speakers per unit area can be reduced, and an increase in cost can be prevented.

For example, the conventional Patent Document 1 describes a sound energy source, a housing that supports sound energy, a passage capable of directing the sound energy generated by the sound energy source to the outside of the housing, and a sound energy emitted from the passage. It has a bottom wall that diffracts at least a portion of the housing and points towards the vertical axis of the housing, thereby providing a housing designed to form a distribution of sound energy downward in the radial direction from the loudspeaker. A ceiling-mounted loudspeaker consisting of is disclosed.

Further, the conventional Patent Document 2 is a ceiling speaker device installed on the ceiling of a room, which includes a speaker for direct sound generation and a speaker for generating reflected sound in the same package, and the speaker for direct sound generation is the main. The speaker is a directional speaker and the sound radiation direction is fixed in the package so that the sound radiation direction faces directly below the vertical direction. The reflected sound generation speaker is a directional speaker, and the sound radiation direction is 30 with respect to the vertical direction. Direct sound generation speakers can be used to localize the sound output from the reflected sound generation speakers in a specific area of the room by fixing them in the package so that they face the lower side wall of the room at an angle in the range of degrees to 75 degrees. A ceiling speaker device characterized by lowering the localization of the sound output from the speaker is disclosed.

However, in the conventional ceiling-embedded speaker, for example, as illustrated in the conventional patent document 3, a substantially acoustic cabinet is embedded in the ceiling surface, and there are few portions protruding downward from the ceiling surface. Is often desirable. The ceiling-embedded speaker has a problem that it tends to be difficult to widen the directivity if the speaker is configured so that the portion protruding downward from the ceiling surface is small. Further, even for the purpose of improving the directivity of the ceiling-embedded speaker, if there are many portions protruding downward from the ceiling surface, the appearance may be deteriorated and the speaker may not be preferred.

Japanese Unexamined Patent Publication No. 7-312792 Japanese Patent No. 5577949 Japanese Patent No. 4161995

The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to widen the directivity of a ceiling-embedded speaker even when the cabinet is embedded in the ceiling. The purpose of the present invention is to provide a ceiling-embedded speaker in which the difference in sound pressure level between the position directly under the embedded speaker and the position away from the speaker is reduced.

The ceiling-embedded speaker of the present invention includes a cabinet that is mounted so as to be embedded in a mounting hole on the ceiling surface, and at least two speaker units that are mounted on the cabinet and emit sound waves to a space below the ceiling surface. A ceiling-embedded speaker, the cabinet has a flat surface including a flat surface defined on the upper side deeper than the ceiling surface, and a side wall portion defining an annular side wall surface connecting the flat surface and the ceiling surface. The outer peripheral side of the flat surface portion has a mounting portion for mounting the speaker unit so as to project downward from the flat surface and not to protrude downward from the side wall portion, and each speaker unit approaches the side wall portion with its diaphragm. Two identical speaker units, which are tilted so as to be attached to the mounting portion and are arranged adjacent to each other, are connected so as to emit sound waves having an opposite phase relationship.

Preferably, in the ceiling-embedded speaker of the present invention, the cabinet further has a flange portion that projects outward from the side wall portion and engages with an edge portion that defines a mounting hole for the ceiling surface, and the side wall surface of the side wall portion. The cross section defining the above includes an arc in contact with the flange portion, and is formed in a substantially convex shape on the inner peripheral side.

Further, preferably, in the ceiling-embedded speaker of the present invention, the mounting portion of the cabinet includes the side wall surface and the mounting surface of the speaker unit inclined with respect to the flat surface, and the area of the mounting surface is sufficiently narrower than the flat surface. It is formed to be.

Further, preferably, in the ceiling-embedded speaker of the present invention, the side wall portion of the cabinet is formed in a substantially annular shape, and at least four identical speaker units are pointed with a central point defining the substantially annular ring in between. They are arranged symmetrically.

Further, preferably, the ceiling-embedded speaker of the present invention is a tweeter in which the speaker unit emits sound waves in a high frequency range higher than a predetermined frequency, and a sound wave containing a frequency lower than that in the high frequency range is directed downward. A second radiating speaker unit is further mounted on the flat surface of the flat surface of the cabinet.

Further, preferably, the ceiling-embedded speaker of the present invention has a frame body that covers at least the mounting portion and the flat surface and is mounted on the cabinet so as not to protrude downward from the flange portion, and is radiated from the speaker unit. A grill with a window through which the sound waves pass is further provided.

Hereinafter, the operation of the present invention will be described.

The ceiling-embedded speaker of the present invention includes a cabinet that is mounted so as to be embedded in a mounting hole on the ceiling surface, and at least two speaker units that are mounted on the cabinet and emit sound waves to a space below the ceiling surface. Be prepared. The cabinet has a flat surface portion including a flat surface defined on the upper side deeper than the ceiling surface, a side wall portion defining an annular side wall surface connecting the flat surface and the ceiling surface, and a lower side from the flat surface on the outer peripheral side of the flat surface portion. It has a mounting portion for mounting the speaker unit so as not to protrude downward from the side wall portion.

Here, each of the two speaker units is tilted so that the diaphragm approaches the side wall portion and is attached to the mounting portion, and two identical speaker units arranged adjacent to each other are in an opposite phase relationship. It is connected to emit sound waves. Therefore, the ceiling-embedded speaker of the present invention reflects sound waves to the side wall surface of the side wall portion in an inverted phase relationship radiated from the diaphragm of the speaker, which is a direct radiation type electroacoustic converter mounted at an angle. As a result, the directivity can be widened even though the speaker unit is mounted so that it does not protrude downward from the side wall, that is, it hardly protrudes downward from the ceiling surface, and the speaker unit is embedded in the ceiling. It is possible to reduce the difference in sound pressure level between the position directly below and the position away from the ceiling-embedded speaker.

Preferably, the ceiling-embedded speaker further comprises a flange portion in which the cabinet projects outward from the side wall portion and engages with an edge defining a mounting hole for the ceiling surface, defining the side wall surface of the side wall portion. The cross section may include an arc in contact with the flange portion and may be formed in a substantially convex shape on the inner peripheral side. Further, the mounting portion of the cabinet includes the mounting surface of the speaker unit that is inclined at an angle of, for example, about 45 degrees with respect to the side wall surface and the flat surface, and is formed so that the area of the mounting surface is sufficiently narrower than the flat surface. Is preferable. By properly designing the cross-sectional shape of the side wall surface to be reflected, or by minimizing the mounting surface of the mounting part to minimize the effect, the peak that occurs in the sound pressure frequency characteristics of the sound waves emitted by the ceiling-embedded speaker. It is possible to suppress the dip and realize more preferable sound reproduction.

In the ceiling-embedded speaker, the side wall of the cabinet is formed in the shape of a substantially annulus, and at least four identical speaker units are arranged point-symmetrically with a central point defining the approximately annulus in between. You may. Further, the speaker unit is a tweeter that emits sound waves in a high frequency range higher than a predetermined frequency, and a second speaker unit that emits sound waves having a frequency lower than that in the high frequency range downward is a flat portion of the cabinet. It may be further attached to the plane of. The directivity can be widened in the entire band, and the difference in sound pressure level between the position directly under the ceiling-embedded speaker and the position away from the ceiling-embedded speaker can be reduced.

In addition, the ceiling-embedded speaker has a frame that covers at least the mounting portion and the flat surface and is mounted on the cabinet so as not to protrude downward from the flange portion, and a window through which sound waves radiated from the speaker unit pass. A grill having a portion may be further provided. Even a ceiling-embedded speaker with improved directivity can be covered with a grill so that the portion protruding downward from the ceiling surface is reduced, which has the advantage of improving the appearance.

The ceiling-embedded speaker of the present invention has wide directivity even when the cabinet is embedded in the ceiling, and the difference in sound pressure level between the position directly under the embedded speaker and the position away from the speaker is reduced. Can be done.

It is a perspective view which shows the concrete structure of the ceiling-embedded speaker of this invention. It is a partial cross-sectional view which shows the concrete structure of the ceiling-embedded speaker of this invention. It is a graph which shows the standardized directional sound pressure frequency characteristic in the BOB plane of the ceiling-embedded speaker of this Example. It is a graph which shows the standardized directional sound pressure frequency characteristic in the BOB plane of the ceiling-embedded speaker of the comparative example. It is a partial cross-sectional view which shows the concrete structure of the ceiling-embedded speaker of another Example of this invention.

Hereinafter, the ceiling-embedded speaker according to the preferred embodiment of the present invention will be described, but the present invention is not limited to these embodiments.

1 and 2 are perspective views illustrating a ceiling-embedded speaker 1 according to a preferred embodiment of the present invention. Specifically, FIG. 1 is a perspective view in which the ceiling-embedded speaker 1 mounted on the ceiling surface 2 extending on the illustrated XY plane is looked up from the indoor side in the Z-axis direction. FIG. 5 is a cross-sectional view taken along the line AO on an XX plane including a central axis U passing downward through the center point O of the ceiling-embedded speaker 1. In the following description and figures, description and illustration of a configuration unnecessary for the description of the present invention will be omitted.

The ceiling-embedded speaker 1 of the present embodiment is mounted so that the cabinet 10 is embedded in a mounting hole 3 which is a circular hole provided in a plate material constituting the ceiling surface 2. The ceiling-embedded speaker 1 includes a cabinet 10 and speaker units 21, 22, 23, 24, and 25, which are electroacoustic transducers attached to the cabinet 10. The speaker units 21, 22, 23, 24, and 25 are attached so that the diaphragms that radiate the respective sound waves are exposed toward the indoor space 5 below the ceiling surface 2. Therefore, the ceiling-embedded speaker 1 does not radiate sound waves to the space 4 above the ceiling surface 2, but radiates sound waves to the indoor space 5 below the ceiling surface 2.

Since the ceiling-embedded speaker 1 is used for loudspeaking in the indoor space 5, a plurality of the ceiling-embedded speakers 1 may be connected and arranged at appropriate installation intervals so as to reproduce the same sound. The ceiling-embedded speaker 1 has a wide directivity, that is, the sound pressure level in the direction of the central axis U (direction angle θ = 0 degrees) directly below the ceiling-embedded speaker 1 and the ceiling-embedded speaker 1. It is required that the difference between the sound pressure level in the direction of the directivity angle θ (however, its absolute value is 90 degrees or less) away from the directly below the type speaker 1 is small.

The ceiling-embedded speaker 1 includes a cabinet 10 which is a housing made of resin. The housing of the cabinet 10 defines a substantially cylindrical space that functions as an acoustic capacity, and the speaker 21 is attached to the center of a flat surface portion 11 including a flat surface 11a defined on the upper side deeper than the ceiling surface 2. There is. The speaker unit 21 is a woofer provided with a diaphragm having a diameter of about 10 cm and radiating sound waves of a predetermined frequency or less.

Further, the cabinet 10 defines a side wall portion 16 that defines an annular side wall surface 17 that connects the flat surface 11a of the flat surface portion 11 and the ceiling surface 2, and a mounting hole 3 that projects from the side wall portion 16 to the outer peripheral side. It has a flange portion 18 that locks to the edge portion to be used. In this ceiling-embedded speaker 1, only the flange portion 18 that locks to the edge portion of the mounting hole 3 projects downward from the ceiling surface 2, so that the appearance as a ceiling speaker is improved and an aesthetically pleasing impression is given. give.

The cabinet 10 of the ceiling-embedded speaker 1 is a speaker unit so as to project downward from the flat surface 11a of the flat surface portion 11 on the outer peripheral side of the flat surface portion 11 near the side wall portion 16 and not to protrude downward from the side wall portion 16. It comprises mounting portions 12, 13, 14 or 15 for mounting 22, 23, 24 or 25, respectively. The speaker units 22, 23, 24, and 25 are the same speaker unit, are provided with a dome diaphragm having a small diameter, and are tweeters that radiate sound waves of a predetermined frequency or higher. Therefore, the speaker units 22, 23, 24, and 25 are smaller than the speaker unit 21, and project downward from the flat surface 11a on the outer peripheral side of the flat surface portion 11 and substantially protrude downward from the ceiling surface 2. It can be attached to the attachment portions 12, 13, 14 or 15, respectively, so as not to be attached.

The mounting portion 12 of the cabinet 10 includes a side wall surface 17 and a mounting surface 12a for mounting the speaker unit 22 that is inclined at an angle of about 45 degrees with respect to the flat surface 11a. The area of the mounting surface 12a is formed so as to be sufficiently smaller than the flat surface 11a of the flat surface portion 11. That is, the area of the mounting surface 12a is set narrow enough to secure the minimum area required for mounting the speaker unit 22, and as a result, the area is sufficiently narrower than the flat surface 11a of the flat surface portion 11.

Similarly, the mounting portion 13 of the cabinet 10 includes a side wall surface 17 and a mounting surface 13a for mounting the speaker unit 23 that is inclined at an angle of about 45 degrees with respect to the flat surface 11a. The area of the mounting surface 13a is formed so as to be sufficiently smaller than the flat surface 11a of the flat surface portion 11. The mounting portions 14 and 15 of the cabinet 10 are the same as the mounting portions 12 and 13.

Since the cabinet 10 of the ceiling-embedded speaker 1 is mounted in the mounting hole 3 which is a circular hole of the ceiling surface 2, the side wall portion 16 and the flange portion 18 of the cabinet 10 correspond to the mounting hole 3. It is formed in the shape of a substantially ring. In the case of this embodiment, the cross-sectional shapes of the side wall portion 16 and the flange portion 18 are uniform in the circumferential direction, and as shown in FIG. 2, a substantially cylindrical shape that is orthogonal to the plane of the plane portion 11. It has a side wall surface 17 which is an inner diameter surface of the above.

The speaker units 22, 23, 24, and 25 have mounting surfaces that are inclined so that their diaphragms face the outer peripheral side from the center point O of the ceiling-embedded speaker 1 on the outer peripheral side of the flat surface portion 11 near the side wall portion 16. It is attached to the attachment portions 12, 13, 14 and 15 having the above. Therefore, the sound wave radiated from the diaphragm is reflected by the side wall surface 17 of the side wall portion 16, and the shapes of the side wall surface 17 and the flange portion 18 of the side wall portion 16 affect the directional characteristics of the ceiling-embedded speaker 1.

FIG. 3 is a graph showing the standardized directional sound pressure frequency characteristics (1 kHz to 20 kHz) in the BB cutting plane in FIGS. 1 of the speaker units 22 to 25 of the ceiling-embedded speaker 1. On the other hand, FIG. 4 shows a standardized directional sound pressure frequency characteristic (1 kHz) in the BB cutting plane in FIG. 1 of the speaker units 22 to 25 of another (not shown) ceiling-embedded speaker 100 as a comparative example. It is a graph which shows ~ 20kHz). The ceiling-embedded speaker 100 of the comparative example is a general ceiling-embedded speaker having only a full-range speaker mounted substantially in the center of the cabinet like the speaker unit 21 of the ceiling-embedded speaker 1.

In FIGS. 3 and 4, the cases where the directivity angles θ are −90 degrees, −60 degrees, −30 degrees, 0 degrees, +30 degrees, +60 degrees, and +90 degrees are displayed in a graph. The graph of the sound pressure characteristic at each directivity angle is standardized and displayed according to the sound pressure level at the directivity angle θ = 0 degree, which is the direction of the central axis U. Therefore, the characteristic of θ = 0 degrees is 0 dB over all frequencies. Further, in the standardized directivity sound pressure frequency characteristic, the level displayed in the graph at any frequency becomes closer to 0 dB as the speaker has a wide directivity characteristic in which the directivity does not change according to the directivity angle. On the other hand, as the directivity becomes narrower, the level displayed in the graph becomes farther from 0 dB as the directivity angle θ becomes larger.

In the ceiling-embedded speaker 1 of the present embodiment, the same four speaker units 22, 23, 24, and 25 are arranged point-symmetrically with a center point O defining a substantially circular ring. That is, the four speaker units 22, 23, 24, and 25 are arranged at intervals of 90 degrees from the center point O to the center. Further, two identical speaker units 22 and 23 arranged so as to be adjacent to each other are connected so as to radiate sound waves having an opposite phase relationship. Further, the adjacent speaker units 23 and 24, the adjacent speaker units 24 and 25, and the adjacent speaker units 25 and 22 are connected so as to emit sound waves having an opposite phase relationship with each other.

Therefore, in the cross section of the XZ plane shown in FIG. 2, the right half, which is line-symmetrical, is not shown. Further, in FIGS. 3 and 4 and the graph of the directivity characteristic described later, the directivity angle θ shows a range of −90 degrees or more and 90 degrees or less. The same four speaker units 22, 23, 24, and 25 are connected in parallel or in series so that two adjacent speakers emit sound waves having an opposite phase relationship. It may have been done.

As shown in the graph of FIG. 3, the ceiling-embedded speaker 1 shows that the directivity changes in the BB plane in the high frequency range of 1 kHz or higher according to the directivity angle becomes small, and the directivity is wide. ing. In particular, when the directivity angle θ = 30 degrees or 60 degrees, the high frequency band of 4 kHz or more is not attenuated to the extent that it is almost within ± 5 dB. Further, even in a high frequency band of 10 kHz or more, there is almost no attenuation within the range of −10 dB to +5 dB.

As shown in the graph of FIG. 3, the ceiling-embedded speaker 1 has a small change in directivity according to the directivity angle in both the XZ plane and the YZ plane, and is oriented even when the speaker unit 21 is further included. The characteristics become wider. On the other hand, in the ceiling-embedded speaker 100 of the conventional comparative example, as shown in the graph of FIG. 4, it can be seen that the high frequency band of 2 kHz or more is significantly attenuated as the directivity angle increases. When the directivity angle θ = 30 degrees or 60 degrees, the difference from the case where the directivity angle θ is 0 degrees is large.

As shown in FIG. 2, the side wall portion 16 of the ceiling-embedded speaker 1 of this embodiment has a side wall surface 17a which is a substantially cylindrical inner diameter surface orthogonal to the plane of the plane portion 11. As a result, the sound wave radiated from the diaphragm of the speaker unit 22 or 23 attached to the attachment portion 12 or 13 having the attachment surface inclined so as to face the outer peripheral side is reflected by the side wall surface 17 of the side wall portion 16. , The effect appears. Further, since the area of the mounting surface 12a or 13a of the mounting portion 12 or 13 is set narrow enough to secure the minimum area required for mounting the speaker unit 22 or 23, the vibration of the speaker unit 22 or 23 is set. The effect of reflection of sound waves radiated from the plate is relatively small.

However, in the ceiling-embedded speaker 1, since two identical speaker units 22 and 23 arranged adjacent to each other are connected so as to radiate sound waves having an opposite phase relationship, the directivity characteristic of FIG. 4 is shown. As shown in the graph of, the ceiling-embedded speaker 1 has a wide directivity even when it is embedded in the ceiling and installed.

FIG. 5 is a perspective view illustrating a ceiling-embedded speaker 1a according to another preferred embodiment of the present invention. Specifically, FIG. 5 is a cross-sectional view taken along the line AO on the XZ plane including the central axis U passing downward through the center point O of the ceiling-embedded speaker 1a. The ceiling-embedded speaker 1a of the present embodiment differs from the ceiling-embedded speaker 1 of the previous embodiment only in the shape of the side wall portion 16a and the side wall surface 17a of the cabinet 10a. Therefore, in the following description and figures, description and illustration of configurations unnecessary for the description of the present invention will be omitted.

As shown in FIG. 5, the side wall portion 16a of the cabinet 10a of the ceiling-embedded speaker 1a includes an arc whose cross section defining the side wall surface 17a is in contact with the flange portion 18, and is substantially convex toward the inner peripheral side. Is formed in. Also in the case of this embodiment, the cross-sectional shapes of the side wall portion 16a and the flange portion 18 are uniform in the circumferential direction, and as shown in FIG. 5, the side wall portion 16a and the flange portion 18 correspond to the mounting holes 3. It is formed in the shape of a substantially annular ring.

The speaker units 22, 23, 24, and 25 have mounting surfaces that are inclined so that the diaphragm faces the outer peripheral side from the center point O of the ceiling-embedded speaker 1a on the outer peripheral side of the flat surface portion 11 near the side wall portion 16a. It is attached to the attachment portion 12, 13, 14 or 15. Therefore, the sound wave radiated from the diaphragm is reflected by the side wall surface 17a of the side wall portion 16a, and the shapes of the side wall surface 17a and the flange portion 18 of the side wall portion 16a affect the directional characteristics of the ceiling-embedded speaker 1a.

The side wall portion 16a of the ceiling-embedded speaker 1a of this embodiment includes an arc whose cross section defining the side wall surface 17a is in contact with the flange portion 18, and is formed substantially convex on the inner peripheral side. As a result, the sound waves radiated from the diaphragms of 22, 23, 24 and 25 mounted on the mounting portions 12, 13, 14 or 15 having the mounting surface inclined so as to face the outer peripheral side are emitted from the side wall portion 16a. Although it is reflected by the side wall surface 17a, its influence is reduced. The above result appears in the graph of the directivity, and the ceiling-embedded speaker 1a has a wide directivity even when it is embedded in the ceiling and installed.

The ceiling-embedded speaker 1 or 1a may further include a grill (not shown), which is omitted in FIG. 1 or 2. The grill that protects the speaker unit 21 and 22 to 25 has a frame that covers the flat surface portion 11 and the side wall portion 16 and is attached to the cabinet 10 so as not to protrude significantly downward from the flange portion 18, and the speaker unit. It suffices to have a window through which the sound waves radiated from 21 and 22-25 pass. The grill may be provided with a net, a net, a punching metal, or the like that covers the window portion of the frame.

Further, in the ceiling-embedded speaker 1 or 1a, since the cabinet 10 or 10a is mounted in the mounting hole 3 which is a circular hole of the ceiling surface 2, the side wall portion 16 or 16a and the flange portion 18 are mounted. , It is formed in the shape of a substantially annular ring corresponding to the mounting hole 3. However, when the mounting hole 3 is rectangular, the cabinet 10 or 10a may have a rectangular annular shape corresponding to the mounting hole 3.

The housing of the cabinet 10 of the ceiling-embedded speaker 1 does not have to define a substantially cylindrical space that functions as an acoustic capacity. Further, the mounting surface 12a of the mounting portion 12 of the cabinet 10 may be tilted so that the diaphragm approaches the side wall portion even if the angle is not about 45 degrees with respect to the side wall surface 17 and the flat surface 11a.

Further, the speaker units 21 and 22 to 25 of the above embodiment are not limited to the electrokinetic speaker which is an electrokinetic electroacoustic converter. The speaker units 21 and 22 to 25 may use speakers by other electroacoustic transducers, such as piezoelectric type or electrostatic type.

The ceiling-embedded speaker of the present invention is not limited to mounting on the ceiling surface as shown in the figure, and may be applied to an embedded speaker mounted so as to be embedded in a wall surface constituting a room.

1, 1a Ceiling embedded speaker 2 Ceiling surface 3 Mounting holes 10a, 10b Cabinet 11 Flat surfaces 12, 13 Mounting parts 16a, 16b Side wall parts 17a, 17b Side wall surface 18 Flange parts 21, 22, 23, 24, 25 Speaker units

Claims (6)

A ceiling-embedded speaker including a cabinet mounted so as to be embedded in a mounting hole on the ceiling surface, and at least two speaker units mounted on the cabinet and radiating sound waves in a space below the ceiling surface. hand,
The cabinet has a flat surface portion including a flat surface defined on the upper side deeper than the ceiling surface, a side wall portion defining an annular side wall surface connecting the flat surface and the ceiling surface, and an outer peripheral side of the flat surface portion. It has a mounting portion for mounting the speaker unit so as to project downward from the flat surface and not to protrude downward from the side wall portion.
A sound wave in which two identical speaker units, each of which is attached to the mounting portion by tilting the diaphragm so as to approach the side wall portion and is arranged adjacent to the speaker unit, have an opposite phase relationship. Connected to radiate,
Ceiling-embedded speaker. The cabinet further has a flange portion that projects outward from the side wall portion and engages with an edge portion that defines the mounting hole on the ceiling surface.
The cross section defining the side wall surface of the side wall portion includes an arc in contact with the flange portion and is formed in a substantially convex shape on the inner peripheral side.
The ceiling-embedded speaker according to claim 1. The mounting portion of the cabinet includes the side wall surface and the mounting surface of the speaker unit that is inclined with respect to the plane, and the area of the mounting surface is formed so as to be sufficiently narrower than the plane.
The ceiling-embedded speaker according to claim 1 or 2. The side wall portion of the cabinet is formed in a substantially annular shape, and at least four of the same speaker units are arranged point-symmetrically with respect to a central point defining the substantially annular ring.
The ceiling-embedded speaker according to any one of claims 1 to 3. The speaker unit is a tweeter that emits sound waves in a high frequency range higher than a predetermined frequency, and a second speaker unit that emits sound waves having a frequency lower than the sound waves in the high frequency range downward is the said cabinet. Further attached to the plane of the flat surface,
The ceiling-embedded speaker according to any one of claims 1 to 4. A grill having a frame that covers at least the mounting portion and the flat surface and is mounted on the cabinet so as not to protrude downward from the flange portion, and has a window portion through which sound waves radiated from the speaker unit pass. Further prepare,
The ceiling-embedded speaker according to any one of claims 2 to 5.