JPH043699A - Speaker system - Google Patents

Abstract

PURPOSE:To increase a sound pressure level in a low-pitched sound area by providing a shielded member to close space between the back plane and the wall plane of a speaker system, and providing a ventilation port making back plane sound pass and in the inside of which a sound absorbing material is provided in the system. CONSTITUTION:The speaker system is comprised in such a way that the ventilation port 10 that can change permeability by using the sound absorbing material is provided in a wall mounting type speaker system, and the shielded member 14 to prevent the back plane sound radiating from a part other than the ventilation port 10 to the front is provided. By employing such constitution, the sound radiated from the back planes of low-pitched sound area speakers 11a, 11b can be radiated only from the port aperture of the ventilation port 10, and energy can be reduced by making pass the sound absorbing material in the ventilation port 10. In such a way, canceling with front plane sound can be reduced, and also, since the back plane is not perfectly sealed, stiffness on a system back plane can be prevented increasing, and the sound pressure level in the low-pitched sound area can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a wall-mounted speaker system used as an indoor and outdoor sound reproduction device.

BACKGROUND OF THE INVENTION In recent years, speaker systems that do not require a large installation space have been developed due to the trend toward lighter, thinner, and smaller speakers.

Among these, there is a speaker system that reproduces a low distortion and plane wave-like sound field by reducing the depth and increasing the area of the diaphragm.

Hereinafter, the conventional speaker system as described above will be explained with reference to the drawings.

FIG. 2(a) is a front view of a thin, large-area speaker system mounted on a wall, and FIG. 2(b) is a side view taken along line AA' in FIG. 2(a). In FIG. 2, 1 is a frame, 2 is a stand, 3a and 3b are low-range speakers, 4 is a mid-to-high range speaker, and 5 is a baffle. A stand 2, low-range speakers 3a and 3b of a semi-rear open cabinet having both a closed part and an open part, a mid-high range speaker 4, and a baffle 5 are fixed to a frame 1 attached to a wall surface.

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

Since a large number of the low frequency speakers 3a and 3b are arranged next to each other, the baffle surface becomes large, and the sound pressure in the low frequency range increases due to the panfle effect. However, since the bass speakers 3a and 3b also emit sound from the back of the cabinet, the sound from the back of the speaker is goes around to the front of the speaker and cancels out the sound from the front, which is in opposite phase to the sound from the back, resulting in a sound pressure characteristic as shown in FIG. 4B.

In order to eliminate this cancellation 7, if the space behind the speaker system is sealed, the space between the wall and the speaker system is small, so the volume of the sealed space is small, and the stiffness increases. At low frequencies where the amplitude of the diaphragm 7 is large, the sound pressure decreases, and the sound pressure characteristics become as shown in A in FIG. 4.

Problems to be Solved by the Invention As mentioned above, conventional speaker systems suffer from a problem of low sound pressure in the bass range, and in order to obtain a rich bass feel, it has been desired to improve the efficiency of the bass range. .

In view of the above-mentioned problems, the present invention aims to prevent sound pressure reduction in the bass range due to bass cancellation and stiffness at the back of the system, and increase sound pressure in the bass range.

Means for Solving the Problems To achieve this object, the speaker system of the present invention is a wall-mounted type speaker system that is equipped with a ventilation port that can change the ventilation rate using a sound absorbing material, and a rear sound The structure includes a shield to prevent radiation from radiating to the front from other sources.

Effect With this configuration, the sound radiated from the back of the bass speaker is radiated to the front only from the port opening of the ventilation boat, and the energy is reduced by passing through the sound-absorbing material in the ventilation port, and the sound from the front is canceled out. greatly reduced.

Also, since the front side is not completely sealed, the stiffness at the back of the system does not increase, and the sound pressure level in the low frequency range increases.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1(a) is a front view of a speaker system according to an embodiment of the present invention, and FIG. 1(b) is a side view taken along line BB in FIG. 1(a). In the speaker system shown in FIG. 1, a ventilation boat 10, low-range speakers 11a, llb, mid-high range speakers 12, and a baffle 13 are fixed to a frame attached to a wall, and the space between the back of the system and the wall is shielded. It has a closed configuration with a plate 14.

The sound from the back of the bass speakers lla and llb is radiated to the back, and after being reflected off the wall, it cannot go around to the front because there is a shielding plate, so it passes through the ventilation boat and is radiated to the front. be done.

The back sound, which is a sound that is in the opposite phase to the front sound, is completely 180 degrees out of phase with the front sound immediately after being radiated from the diaphragm, but while it passes through the back of the speaker and is radiated from the ventilation boat 10. The phase difference with the front sound is reduced by the distance. Furthermore, the energy of the back sound is absorbed by the sound absorbing material in the ventilation port 10. That is, when the back sound is synthesized with the front sound, the sound has low energy and little phase shift, so the front sound will not be canceled out to a large extent. Further, since the sound from the back surface can pass through the ventilation boat 10, the stiffness of the back surface does not increase due to shielding the back surface.

As described above, the speaker system of this embodiment can realize an increase in sound pressure in the bass range, as shown by C in the sound pressure characteristic diagram in FIG. 4, compared to the conventional system.

In this example, a sound absorbing material was used in the ventilation port, but
The air permeability may be 100% without using any sound absorbing material. Also,
The vent boat was installed at the bottom of the system, but it could also be at the top.

Effects of the Invention The present invention provides a system that includes at least one low-frequency speaker that radiates sound to the front and rear sides of the speaker system, a shield that closes the space created between the back side of the speaker system and the wall surface, and By providing a ventilation boat with sound absorbing material inside that allows back sound to pass through, the stiffness at the back of the speaker does not increase, and the phase shift between the back sound and the front front is reduced, and the energy of the back sound is reduced. By making it smaller and then combining it with the front and front sounds, it is possible to create an excellent speaker system that can significantly reduce the cancellation of the rear sound and the front front, and increase the sound pressure level in the bass range. be.

[Brief explanation of the drawing]

Fig. 1 is a front view and a side view of a speaker system according to an embodiment of the present invention, Fig. 2 is a front view and a side view of a conventional speaker system, and Fig. 3 is a cross section of a bass speaker viewed from above. FIG. 4, which is a schematic diagram showing the propagation state, is a sound pressure frequency characteristic diagram of the speaker system. 10... Ventilation boat, lla, llb...
...Low range speaker, 12...Medium and high range speaker, 13...Buff full, 14...Shielding plate.

Claims (6)

[Claims] (1) A speaker system using at least one speaker that emits low frequency sounds from the back of the cabinet, a shield provided on the outer periphery of the speaker system to close the space between the back of the speaker system and the wall, and a speaker system. A speaker system characterized by having a ventilation port with a variable ventilation rate installed inside the speaker system, and radiating rear sound from one place to the front at an arbitrary ventilation rate. (2) The speaker system according to claim (1), wherein the shield is made of a wooden board. (3) The speaker system according to claim (1), wherein the ventilation port has a ventilation rate of 100%. (4) The speaker system according to claim (1), wherein the ventilation port is provided at the bottom of the speaker system. (5) Depending on the ventilation rate set by the ventilation port, the sound absorption coefficient,
2. The speaker system according to claim 1, wherein a sound absorbing material having a suitable air permeability is provided in the ventilation port. (6) The speaker system according to claim (1), wherein the ventilation port is constructed as a single unit independent of the speaker.