JPH0417497A - speaker system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a speaker system capable of reproducing powerful deep bass even though it is small.

BACKGROUND OF THE INVENTION Conventionally, a cascade bass reflex system has been used as a compact speaker system capable of reproducing deep bass.

Fig. 6 shows a cross-sectional view of a conventional cascade bass reflex speaker system. In Fig. 6, 1 is the cabinet of the speaker system, 2 is the speaker unit, and 3 is the internal space of the cabinet l divided into two spaces. bulkhead,
4 is a first space divided by the partition wall 3, 5 is a second space, 6 is a first port attached to the partition wall 3, and 7 is a second port attached to the back of the cabinet l.

FIG. 7 is a mechanical equivalent circuit of the speaker system shown in FIG. 6. In Fig. 7, Z is Speakaniknit 2
where C1 is the compliance of the first space 4, PI is the mass of the first port 6, and C2 is the impedance of the second space 5.
compliance, P2 is the mass of the second port 7.

In the speaker system configured as above,
The first space 4, the first port 6, the second space 5 and the second port 7, i.e. two compliances and two masses, create a second space with two anti-resonant frequencies fl, f2.
We have an additional system of degrees of freedom. Therefore, as shown in Figure 8, the sound pressure frequency characteristic is similar to that of a simple bass reflex type speaker system in the frequency range near fl and from above f1 to f2. The sound emitted from the second port 7 and the second port 7 have the same phase, and good frequency characteristics can be obtained.

Problem to be Solved by the Invention However, near the second anti-resonance frequency f2, the level of the sound radiated from the second port 7 increases and its phase is reversed again, causing the sound radiated from the diaphragm to Due to the interference, the frequency characteristic has a problem in that a large dip occurs near r2. Therefore, although it can be used as a super woofer system for reproducing deep bass sounds, it is difficult to use it as a speaker system for reproducing a full range of frequencies.

Means for Solving the Problems In order to solve the above problems, the speaker system of the present invention uses a cascade bass reflex system, further includes a second partition so as to constitute a third space, and at least It has one hole or port.

Operation The present invention has the above-described configuration, so that the resonant frequency of the Helmholtz resonator constituted by the third space and the hole or port provided in the second partition is equal to the above-mentioned frequency f2.
By adjusting the size of the third space, hole, or port to match, the second anti-resonance at frequency f2 caused by the cascade bass reflex system can be absorbed by the Helmholtz resonator, and the sound The sharp dip characteristic near f2 on the pressure frequency characteristic can be significantly improved.

EXAMPLE A speaker system according to an example of the present invention will be described below with reference to the drawings.

FIG. 1 shows a sectional view of a speaker system according to a first embodiment of the present invention, FIG. 2 shows its mechanical equivalent circuit, and FIG. 3 shows a specific example of its sound pressure frequency characteristics.

In FIG. 1, cabinet 1. speaker unit 2
．． Partition wall 3. First space4. The second space 5°, the first port 6 and the second port 7 are the same as in FIG. 8 is a second partition wall provided inside the second space 5; 9 is a second partition wall provided inside the second space 5;
A third space 10 formed by the partition wall 8 is a hole provided in the second partition wall 8 so as to constitute a Helmholtz resonator together with the third space 9.

In FIG. 2, Z is the impedance composed of the mass, compliance, and resistance caused by the speaker unit 2, CI is the compliance of the first space 4, and Pl
is the mass of the first port 6, C2 is the compliance of the second space 5, P2 is the mass of the second port 7, C3 is the third
The compliance of the space 9, P3, is the mass of the hole 10.

The operation of the speaker system configured as described above will be described below with reference to FIGS. 1, 2, and 3.

As described in the conventional example, in a simple cascade bass reflex type speaker system, the first space 4, the first port 6, the second space 5, and the second port 7 in FIGS. 1 and 2, That is, two compliance C
I, C2 and two masses P1. P2 and two anti-resonant frequencies fl.

We additionally have a two-degree-of-freedom system with f2. Then, near the second anti-resonance frequency f2, the level of the sound emitted from the second port 7 increases and its phase is reversed again, and due to interference with the sound emitted from the diaphragm, the frequency The characteristic is that a large dip occurs near r2. Here, the third space 9 and the hole l
so that the resonant frequency of the Helmholtz resonator constituted by O is approximately equal to the second anti-resonant frequency f2,
By adjusting the volume of the third space 9 and/or the diameter of the hole 10, the second anti-resonance can be adjusted between P3 and 03 in FIG.
It is absorbed by the resonance of the Helmholtz resonator composed of. Therefore, the air vibration inside P2, that is, the second port, is suppressed, and as shown in FIG. 3, the dip in the sound pressure frequency characteristic near f2 is significantly improved.

As described above, according to this embodiment, in a cascade bass reflex type speaker system, the third space and hole are provided, and the resonant frequency of the Helmholtz resonator constituted by these is approximately equal to the second anti-resonant frequency f2. By adjusting the volume of the third space and the diameter of the hole, it is possible to significantly improve the dip in the sound pressure frequency characteristics near the second anti-resonance frequency, thereby improving the playback quality. can be achieved.

A second embodiment of the present invention will be described below with reference to the drawings.

FIG. 4 shows a cross-sectional view of a speaker/stem in a second embodiment of the invention.

4 differs from FIG. 1 in that a third port 11 is provided in the second partition wall 8 instead of a hole. Even with this configuration, the Helmholtz resonator constituted by the third space 9 and the third port 11 operates in the same manner as in the first embodiment, and the sound near the second anti-resonance frequency f2 is The dip on the pressure frequency can be improved. Moreover, by adjusting only the length of the third port 11, the resonant frequency of the Helmholtz resonator can be easily set to around f2.

A third embodiment of the present invention will be described below with reference to the drawings.

FIG. 5 shows a sectional view of a speaker system in a third embodiment of the invention.

The difference between FIG. 5 and FIG. 4 is that the port wall surface 12 constituting the second port 7 is configured so that the cross-sectional area of the port increases smoothly as it goes toward the outside of the cabinet l. .

With such a configuration, it is possible to maintain a smooth flow of air within the port especially when the port resonates in a low frequency range, and it is possible to reduce noise caused by wind noise at the port.

Above 1. Second. In the third embodiment, there is one hole or third port provided in the second partition wall, but there may be a plurality of holes. Further, a plurality of third spaces formed by the second partition walls may also be provided. Further, although the partition walls are provided to divide the cabinet interior space into left and right sides, the present invention is not limited to this. For example, the partition walls may be provided to divide the cabinet interior space into upper and lower sections.

Effects of the Invention As described above, the present invention provides a phase-inverting speaker system in which a port is attached to one side of a cabinet.
A partition wall is provided to divide the space inside the cabin 7, and a port is also provided on this partition wall, and a second partition wall is provided to form a sealed small space, and a third partition wall is also provided on the second partition wall. By arranging ports or holes,
The Helmholtz resonator, which consists of a small sealed space and a third port or hole, absorbs the second anti-resonance of the speaker system, so that the out-of-phase sound radiated from the port to the outside of the cabinet around that frequency is It is possible to realize a flat sound pressure frequency characteristic without dips.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a speaker system according to the first embodiment of the present invention, Fig. 2 is an isometry plane m-view equivalently showing the speaker/stem of Fig. 1 in a mechanical system, and Fig. 3 is a sectional view of a speaker system according to a first embodiment of the present invention. 4 is a sectional view of the speaker system in the second embodiment of the present invention, and FIG. 5 is a mechanical equivalent of the beaker system in the third embodiment of the present invention. FIG. 8 is a sound pressure frequency characteristic diagram of a conventional speaker system. 1... Cabinet, 2... Speaker unit, 3... Partition wall, 4... First space, 5... Second space. Space, 6...1st
Port, 7...Second port, 8...
-Second partition wall, 9...Third space, 10...
...hole, 11...third port, 12...
...Port wall. Name of agent: Patent attorney Shigetaka Awano
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Claims (3)

[Claims] (1) A phase-inverting speaker system consisting of a cabinet, a speaker unit attached to the cabinet, and a port attached to one side of the cabinet, in which at least one partition wall is provided in the cabinet to include the port. The space is divided into a space and a space not including the port, and a second port is also provided in the partition wall, and a sealed space is configured in the space including the port, the space not including the port, or both spaces. Further, a second partition wall is provided, and the second partition wall is provided.
A speaker system characterized in that at least one hole is provided in a partition wall of the speaker system. (2) The speaker system according to claim (1), characterized in that a third port is provided in the hole. (3) The cross-sectional area of the port gradually increases from the central portion toward the open end.
2) The speaker system described.