JPH02202295A - Speaker system - Google Patents

Abstract

PURPOSE:To eliminate the standing waves produced between a speaker cabinet and a wall surface and to obtain the flat frequency characteristics by preparing a module having an acoustic port containing a sound absorbing material at the periphery of the cabinet when the cabinet having an acoustic port on its back is attached to the wall surface. CONSTITUTION:The sound waves produced on the back of a diaphragm 1 are radiated to outside via the inner capacity 4 of a cabinet 3 and then an acoustic port 5. In a speaker system an acoustic space 7 is secured between the back of the cabinet 3 the wall surface so as not to close the port 5 and the cabinet 3 is fixed to the wall surface. A standing wave is produced in the space 7 with a specific frequency decided by the form of the space 7. This standing wave gives the adverse influence to the reproduced sound pressure frequency characteristics of the speaker system to produce the sound pressure characteristics having many deep dips. Thus an acoustic port module 8 containing an acoustic port 9 is prepared around the cabinet 3 in order to suppress the standing wave. That is, the port 9 having an extremely high input/ output frequency of sound waves contains a sound absorbing material 10 to effectively eliminate the standing wave.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a technique for wall-mounting a speaker system having an acoustic hole on the back side of a speaker cabinet.

BACKGROUND OF THE INVENTION Recently, in order to make speaker systems thinner and to minimize abnormal sounds coming from acoustic ports provided in cabinets, speaker systems in which an acoustic hole is placed on the back of a cabinet have been widely used. In addition, due to interior design and the desire to make the living space more spacious, speakers/stem are increasingly being mounted on walls.

Hereinafter, such a speaker system will be explained with reference to the drawings.

FIG. 5 shows a structural sectional view when the speaker/stem having the acoustic port on the back surface of the cabinet described above is attached to a wall using metal fittings (not shown).

In FIG. 6, 1 is a diaphragm, 2 is a free edge, 3 is a cabinet, 4 is an internal volume of the cabinet, 5 is an acoustic port, 6 is a wall surface, and 7 is an acoustic space between the wall surface and the cabinet.

The operation of the speaker system configured as above will be explained below.

An acoustic port 5 is provided on the rear surface of the speaker cabinet 3 to connect the internal volume 4 of the cabinet with the outside, and sound emitted to the rear surface of the diaphragm 1 passes through the acoustic port 5 and is radiated to the rear surface of the cabinet 3. An acoustic space 7 is provided between the cabinet 3 and the wall surface 8 so that the sound radiated from the acoustic port 6 is not sealed off by the wall surface 6. Therefore, the sound radiated to the front and back of the diaphragm 1 is radiated without being closed, so the diaphragm 1 is easy to move.

Problems to be Solved by the Invention However, in the above configuration, since the acoustic space 7 surrounded by the wall surface 6 and the cabinet 3 has a relatively uniform shape, standing waves are likely to occur. The re-frequency characteristic has many peaks and dips at frequencies where standing waves occur. FIG. 2 shows a reproduced sound pressure frequency characteristic diagram of a speaker system having an acoustic port on the back of the cabinet. In the figure, characteristic B is a characteristic diagram of a conventional speaker system, for example, shown in FIG. That is, at frequencies where standing waves are generated in the acoustic space 7, peaks and dips occur, and only disturbed sound pressure characteristics can be obtained.

In view of the above problems, the present invention obtains flat frequency characteristics without peaks and dips caused by standing waves in the acoustic space surrounded by walls and the cabinet, even in a speaker≠field system that has an acoustic port on the back of the speaker cabinet. In addition, in a small volume cabinet, the acoustic space can also be used as a cabinet, and the present invention provides a speaker system that can improve bass reproduction efficiency.

Means for Solving the Problems To achieve this object, the speaker system of the present invention includes: arranging a module having an opening through the front and back of the speaker cabinet around the speaker cabinet; arranging a sound absorbing material in the opening; The sound waves radiated to the back surface of the diaphragm are radiated to the front surface of the diaphragm through this opening.

Effect of the present invention The sound waves radiated from the acoustic ports provided on the back of the speaker cabinet generate standing waves in the acoustic space sandwiched between the wall surface and the cabinet. Although the characteristics have many peaks and valleys, by placing sound absorbing material around the acoustic space sandwiched between the wall and the cabinet, the peaks and dips of the reproduced sound pressure frequency characteristics caused by standing waves in the acoustic space can be reduced. This makes it possible to obtain flat sound pressure frequency characteristics. Furthermore, the acoustic space is equivalent to an increased cabinet volume, making it possible to reproduce lower frequencies.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 shows a speaker system in one embodiment of the present invention. In Figure 1, 1 is the speaker diaphragm, 2 is the free edge, 3 is the cabinet, 4 is the internal volume of the cabinet, 5 is the acoustic port provided on the back of the cabinet, 6 is the wall, and 7 is the wall surrounded by the wall and the cabinet. Acoustic space, 8 is the cabinet of the acoustic port module, 9 is the acoustic port, 10 is the sound absorbing material placed inside the acoustic port, 11 is the floor surface where the speaker system is installed, 12a is the area where the sound from the back is output to the top. It is a shielding plate that prevents people from moving.

The operation of the speaker system configured as described above will be explained below. The speaker diaphragm 1 is driven by a financial mechanism (not shown). The sound waves generated on the back surface of the diaphragm 1 are radiated to the outside from the acoustic port 5 through the cabinet internal volume 4. Here, the speaker system is fixed to the wall with an acoustic space 7 provided between the back of the cabinet and the wall so as not to block the sound (W photo 6). 7, a standing wave is generated at a specific frequency determined by the shape.This standing wave has an adverse effect on the reproduced sound pressure frequency characteristics of the speaker system, resulting in a sound pressure characteristic with many peaks and dips.The speaker of this embodiment the system,
In order to suppress this standing wave, an acoustic port module having an acoustic port is arranged around the acoustic space 7, and a sound absorbing material 10 is arranged inside the acoustic port 9 of this acoustic port module.

In this way, the standing waves excited by the sound waves emitted from the acoustic port 6, as well as the standing waves generated when the sound emitted to the front surface of the diaphragm 1 wraps around and enters the acoustic space 7, It can be removed by the sound absorbing material 1o placed at 9. Furthermore, since the sound absorbing material 1o is arranged at the acoustic port 9 where sound waves enter and exit, standing waves can be effectively removed with a small amount of sound absorbing material. Then, a sound absorbing material 10 is placed on the acoustic port 9 of the modularized acoustic port cabinet 8.
Because of this arrangement, even large systems can be handled in module units, and fixed characteristics can be obtained. As a result, a flat reproduced sound pressure frequency characteristic can be obtained as shown in FIG. 2A. Furthermore, as is clear from the characteristics shown in FIG. 2A, since the acoustic space 7 can also be used as a part of the rear volume of the diaphragm, there is an advantage that the low frequency reproduction sound pressure characteristics are improved.

FIG. 3 shows how the sound absorbing material 1o is placed in the acoustic port 9 of the acoustic port module cabinet 8. The sound absorbing material 1o is often made of thin fibrous material such as glass wool that has a high sound absorbing effect, so the mesh 13a has small openings on both sides of the sound absorbing material 1o to prevent the sound absorbing material from protruding outside.

13b is placed. By doing so, the sound-absorbing material 10 does not fly out and scatter, does not impede the entry and exit of sound waves, has a clean appearance, and achieves the performance of the acoustic port module.

FIG. 4 shows a perspective view of a case where a plurality of speaker systems are arranged on a wall surface. Acoustic port module cabinets 8 are arranged on a floor surface 11, on which the speaker cabinets 3 shown in FIG. 1 are arranged in two tiers, and further above that, acoustic port module cabinets 8 are arranged. The sound waves radiated to the back surface of the diaphragm 1 are allowed to enter and exit only through the acoustic ports, and the rest are covered by shielding plates 12a and 12b. Therefore, the back sound enters and exits only through the acoustic port section, and the sound absorbing material 10 placed in the acoustic port section 9 acts as a base for the system, making it easy to configure the system. This allows easy assembly.

Effects of the Invention As described above, the present invention provides a method in which, when a cabinet having an acoustic port on the back side is installed on a wall, the cabinet with the acoustic port is placed around the cabinet, and a sound absorbing material is placed inside the acoustic port. When placed, this sound absorbing material can eliminate standing waves generated between the speaker cabinet and the wall surface, and can obtain flat frequency characteristics.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of the speaker system of the present invention at -'1lll, FIG. 2 is a sound pressure frequency characteristic diagram of the speaker system, and FIG. 3 is a sectional view of the acoustic port module of the embodiment of the present invention. FIG. 4 is a perspective view of a speaker system comprising a plurality of speaker cabinets and a plurality of acoustic port modules according to an embodiment of the present invention, and FIG. 6 is a sectional view of a conventional speaker system. 1... diaphragm, 2... free edge,
3...cabinet, 4...cabinet internal volume, 5...acoustic port, 6...
...Wall surface, 7...Acoustic space between wall surface and cabinet, 8...Acoustic port cabinet, 9.
...Acoustic port, 1o...Sound absorbing material, 11
. . . Floor surface, 12a, 12b . . . Shielding plate, 13a. 13b...Metush. Name of agent: Patent attorney Shigetaka Awano and 1 other person f.
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Claims (3)

[Claims] (1) An acoustic port is opened on the back of the speaker cabinet to acoustically connect the internal volume of the speaker cabinet to the outside, and when the speaker cabinet is installed at an appropriate distance from the wall, the acoustic space on the back of the speaker cabinet is opened. 1. A speaker system comprising a module having an acoustic port section that acoustically connects the front surface of the diaphragm and the front surface of the diaphragm. (2) The speaker system according to claim 1, characterized in that a sound absorbing material is arranged in the acoustic port portion of the module, and a mesh is arranged in front of the sound material. (3) A module having an acoustic port section is arranged on the floor, and the speaker system is arranged on the upper part of the module, and the space surrounded by the speaker system and the wall and the front surface of the speaker are connected to the acoustic port of the module. Claim 1 characterized in that the parts other than the parts are shielded so as not to be connected.
Speaker system as described.