JP3271433B2 - Speaker system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loudspeaker system used as an indoor / outdoor sound reproducing apparatus, and more particularly to a passive loudspeaker system for reducing abnormal sound radiation.

[0002]

2. Description of the Related Art In recent years, as one of techniques for cutting the middle and high frequencies in reproducing low-pitched sound of a speaker system, there have appeared several methods of cutting with an acoustic filter using a passive radiator without using an electric filter. Hereinafter, an example of the above-described conventional speaker system will be described with reference to the drawings.

FIGS. 3 and 4 show a conventional bass reproducing speaker system with a passive radiator. FIG. 3 is a partially cutaway perspective view, FIG. 4 is a side sectional view showing the structure, and FIG. It is a part side sectional view. In the figure, a cabinet 5 comprises a passive radiator-side cavity 5a having an opening in the front and a driving speaker unit-side cavity 5b inside thereof, and a diaphragm 1a and a driving plate are provided in front of the driving speaker unit-side cavity 5b. A driving speaker unit 1 having an edge 1b serving as a diaphragm supporting system of the speaker unit is mounted, and a diaphragm 2a and an edge 2b serving as a diaphragm supporting system of a passive radiator are provided in front of a passive radiator side cavity 5a.
Is mounted. The driving speaker unit 1 is driven by the signal input 6.

The operation is described below. The signal input 6 is given by a signal source (not shown) (power amplifier or the like), and the driving speaker unit 1 is driven and supported by the edge 1b. When the diaphragm 1a vibrates, the air pressure of the passive radiator side cavity 5a on the front surface thereof increases and decreases as the diaphragm 1a moves forward and backwards, so that the diaphragm 2a of the passive radiator 2 supported by the edge 2b becomes In response to the forward and backward movements, and generates an acoustic output from the front of the cabinet 5 toward the front.

[0005]

However, in a speaker system having a driving speaker unit and a passive radiator of the above-described conventional example, the frequency at which the movements of the diaphragms of the driving speaker unit and the passive radiator are anti-resonant with each other. In a band, that is, in a frequency band in which vibrations of opposite phases occur, a difference occurs between the air pressure in the passive radiator side cavity 5a and the air pressure outside the cavity, and the difference is remarkable at a large amplitude.

At this time, when a general soft material is used for the edge serving as the support system of the diaphragm, the edge tends to be deformed from the larger air pressure to the smaller air pressure due to the effect of the air pressure difference. . In particular, the edge 2b having a general R shape as shown in FIG. 5 is deformed from a dashed convex line to a solid concave line in FIG. 5 with a decrease in the air pressure in the passive radiator side cavity 5a. There was a problem that sound was emitted. This deformation can occur not only at the edge 2b of the passive radiator 2 but also at the edge 1b of the driving speaker unit 1.

The present invention has been made to solve the above-mentioned conventional problems, and has as its object to provide a speaker system that eliminates abnormal sound from an edge serving as a diaphragm support system.

[0008]

In order to solve the above-mentioned problems, a speaker system according to the present invention comprises a driving speaker unit driven by a signal input, and a passive speaker unit driven in response to vibration of the driving speaker unit. A radiator, a cabinet having a passive radiator-side cavity for mounting the passive radiator on the front surface, and a driving speaker unit-side cavity for mounting the driving speaker unit toward the passive radiator-side cavity; and And an auxiliary diaphragm for reducing a difference in air pressure between the inside and the outside of the passive radiator side cavity. In this configuration, the auxiliary diaphragm is provided on a part of the passive radiator side cavity of the cabinet or a part of the passive radiator diaphragm. And, the material of the auxiliary diaphragm are those internal loss is high, formed a highly stretchable material soft.

[0009]

According to the present invention, the vibrations of the auxiliary diaphragm are vibrated at the frequency at which the movement of the diaphragm of the driving speaker unit and the vibration of the diaphragm of the passive radiator are anti-resonant with each other, that is, at the frequency of the opposite-phase vibration. This reduces the air pressure difference between the inside and the outside of the cavity on the side of the passive radiator, and acts to reduce the deformation of the edge, which is the diaphragm support system, and the emission of abnormal noise due to the deformation.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a speaker system according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a side sectional view showing the structure of the speaker system according to the first embodiment of the present invention. 1, components having the same functions as those in FIGS. 2, 3, and 4 of the conventional example are denoted by the same reference numerals, and description thereof is omitted. On one side surface of the passive radiator side cavity 5a of the cabinet 5, an auxiliary diaphragm 3 made of a soft and highly elastic material, for example, rubber or the like, having a high internal loss is attached.

The operation of the speaker system of the present invention configured as described above will be described below. At a frequency at which the movement of the diaphragm 1a of the driving speaker unit 1 and the movement of the diaphragm 2a of the passive radiator 2 are mutually anti-resonant, that is, a frequency at which the phases of the vibrations are reversed, the diaphragm 1a of the driving speaker unit 1 moves in the negative direction. When the vibration plate 2a of the passive radiator 2 is vibrated in the forward direction, the air pressure in the passive radiator side cavity 5a decreases. Therefore, the vibration of the auxiliary vibration plate 3 provided in the cabinet is to increase the air pressure in the cavity. It vibrates in the negative direction, that is, toward the inside of the passive radiator side cavity 5a.

The diaphragm 1 of the driving speaker unit 1
When “a” is in the positive direction and the vibration plate 2a of the passive radiator 2 is in the negative direction, the air pressure in the passive radiator side cavity 5a increases, so that the vibration of the auxiliary diaphragm 3 provided in the cabinet includes Vibrates in the forward direction, that is, toward the outside of the passive radiator side cavity 5a in order to reduce the change in air pressure.

The radiated sound pressure is a composite of the passive radiator 2 and the auxiliary diaphragm 3, but since the phases are opposite to each other, the sound pressure is reduced. The sound pressure can be arbitrarily set by making the diameter sufficiently smaller than the diameter or adjusting the material hardness or the like.

In this embodiment, the driving speaker unit 1
14 cm, a foamed urethane material for the edge 1b serving as a support system for the diaphragm 1a of the driving speaker unit 1, a passive radiator 2 having a diameter of 20cm, and an edge serving as a support system for the diaphragm 2a of the passive radiator 2. The material 2b was made of urethane foam, and the auxiliary diaphragm 3 was made of a flat plate having a diameter of 4 cm and made of soft rubber (thickness 0.3 mm). The volume of the cavity 5a on the passive radiator side was set to 7 liters, and the volume of the cavity 5b on the driving speaker unit side was set to 13 liters. Thereby, the air pressure difference between the inside and the outside of the passive radiator side cavity 5a could be reduced.

FIG. 2 is a side sectional view showing the structure of a speaker system according to a second embodiment of the present invention. In this embodiment, the auxiliary diaphragm 3 in FIG. 1 of the first embodiment is attached to the center of the diaphragm 2a of the passive radiator 2. Needless to say, this operation is performed in the same manner as in the case of FIG. 1 except that the vibration of the diaphragm 1a of the driving speaker unit 1 and the vibration of the diaphragm 2a of the passive radiator 2 become anti-resonant with each other, that is, the vibration of the opposite phase. At this frequency, the auxiliary diaphragm 3 vibrates in a direction to reduce the air pressure difference between the inside and the outside of the passive radiator side cavity 5a.

As described above, according to each embodiment of the present invention,
By attaching the auxiliary diaphragm 3, the air pressure difference between the inside and the outside of the passive radiator side cavity 5a can be reduced, and the deformation of the edge can be reduced.

[0017]

As described above, according to the present invention, the diaphragm of the driving speaker unit and the diaphragm of the passive radiator are mounted by attaching the auxiliary diaphragm to a part of the cavity of the passive radiator or the diaphragm of the passive radiator. At the frequency where the movements are anti-resonant with each other, that is, at the frequency of the opposite phase vibration, the air pressure difference between the inside and outside of the passive radiator side cavity can be reduced, the edge deformation is reduced, and at the same time the abnormal sound emission due to this deformation is reduced Can be done.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a structure of a speaker system according to a first embodiment of the present invention.

FIG. 2 is a side sectional view showing the structure of the speaker system according to the second embodiment.

FIG. 3 is a partially cutaway perspective view of a conventional speaker system.

FIG. 4 is a side sectional view showing the same structure.

FIG. 5 is a side sectional view of a main part for explaining the operation of the same.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 drive speaker unit 1a diaphragm of drive speaker unit 1b diaphragm support edge of drive speaker unit 2 passive radiator 2a diaphragm of passive radiator 2b diaphragm support edge of passive radiator 3 auxiliary diaphragm 5 cabinet 5a passive Radiator side cavity 5b Driving speaker unit side cavity 6 Signal input

Claims (4)

(57) [Claims] A driving loudspeaker unit driven by a signal input; a passive radiator driven in response to vibration of the driving loudspeaker unit; a passive radiator side cavity for mounting the passive radiator on a front surface; A cabinet having a driving speaker unit side cavity for mounting the driving speaker unit toward the passive radiator side cavity; Speaker system. 2. The speaker system according to claim 1, wherein the auxiliary diaphragm is provided in a cavity on a passive radiator side of the cabinet. 3. The speaker system according to claim 1, wherein the auxiliary diaphragm is provided on a part of the diaphragm of the passive radiator. 4. The speaker system according to claim 1, wherein the material of the auxiliary diaphragm is made of a soft and highly elastic material having a high internal loss.