JPH02301395A - Speaker system - Google Patents

Abstract

PURPOSE:To improve the reproducing capability of a low pitched sound by providing a enclosed acoustic space including a speaker unit rear panel and an open acoustic space opened at an opening into a speaker box with a partition plate and a passive radiator formed in a direction orthogonal to the speaker unit front side. CONSTITUTION:A rear side of a speaker unit 1 is enclosed with an inner wall of a speaker box 2 and a partition plate 3 to form an enclosed acoustic space S1. The partition plate 3 is formed in a direction orthogonal to the buffle face and a passive radiator 3A is fitted to the partition plate 3 via a soft edge 3B. The partition plate 3 forms one side wall of the enclosed acoustic space S1 and forms one side wall of an open acoustic space S2 linked to the outside of the speaker box 2 with the opening 4 at the opposite side. Thus, the enclosed acoustic space S1 promotes the motion of the diaphragm of the speaker unit 1 to emphasize the low pitched sound reproduction output of the speaker unit itself thereby improving more the reproduction capability of the low pitched sound corresponding to the aperture of the speaker 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J] The present invention relates to a speaker system consisting of a speaker unit and a speaker box, and particularly to a speaker system in which bass output is enhanced.

[Summary of the Invention 1 The speaker system of the present invention seals the rear side of a speaker unit in a speaker box with a partition plate to which a passive radiator is attached and is formed in a direction orthogonal to the front surface of the speaker box, thereby creating a sealed acoustic space. Form. Furthermore, this sealed acoustic space is divided by a partition plate having the passive radiator, and an open acoustic space is formed by using this partition plate as one wall and having an opening open to the outside of the speaker box. By doing so, it is possible to improve bass reproduction ability and achieve miniaturization.

[Prior Art] The lowest frequency of acoustic waves reproduced by a speaker is generally limited by the lowest resonant frequency f0 of a diaphragm. Therefore, the bass speaker unit for bass sounds is generally large and heavy, making the speaker system expensive.

Therefore, it has been considered to improve the bass reproduction ability by making various improvements to the speaker box to which the speakers are attached.

Figure 2 shows box B with speaker unit SP installed.
An acoustic duct AD is provided on the front side of the box BX, and the acoustic duct AD guides vibration waves in the bass range emitted from the rear car of the speaker unit SP to the front of the box BX,
This is intended to enhance the bass.

Also, in Figure 3, a passive radiator PR is installed on the front side of the box BX to which the speaker unit SP is attached.
The purpose is to improve bass reproduction ability by setting the resonance frequency of this passive radiator PR (also called a drone cone) to a substantially bass reproduction frequency.

[Problems to be Solved by the Invention] However, in such a speaker system, the speaker unit SP as well as the passive radiator PR and the acoustic duct AD are provided on the baffle surface, so the baffle plate needs to have a certain area or more. Moreover, especially when forming the acoustic duct AD, if it is desired to further emphasize the low frequency range, it is necessary to make the duct longer, and for these reasons, there is a problem in that it is difficult to miniaturize the speaker system.

Further, if the bass reproduction ability of the speaker unit itself is poor, sufficient bass reproduction output cannot be obtained, resulting in a drawback that sufficient bass cannot be obtained.

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned problems.A passive radiator is attached to the back of a speaker unit provided in a speaker box, and a passive radiator is attached to the back of a speaker unit provided in a speaker box. To provide a speaker system in which a sealed acoustic space is sealed by partition plates formed in orthogonal directions, and further, the partition plates serve as one wall to form an open acoustic space having an opening.

[Function] A sealed acoustic space is provided on the back of the speaker unit, and a passive radiator is attached to the wall that forms this space, so this sealed acoustic space promotes the movement of the diaphragm of the speaker unit, causing the speaker unit itself to move. It is possible to enhance the bass reproduction output and further improve the bass reproduction ability corresponding to the speaker diameter. Furthermore, the partition plate having the passive radiator is formed in the horizontal direction (direction perpendicular to the front surface of the speaker box), and
Since it is one wall surface of an open acoustic space, the baffle surface only needs a small area, making it possible to significantly downsize the entire speaker.

[Embodiment] Fig. 1 is a side cross-sectional view of a speaker system showing an embodiment of the present invention, where l is a speaker unit and 2 is a speaker system.
3 is a speaker box, 3 is a partition plate, and 4 is an opening.

The back surface of the speaker unit 1 is sealed by the inner wall of the speaker box 2 and the partition plate 3, forming a sealed acoustic space SI. The partition plate 3 is formed in a direction (horizontal direction in the figure) perpendicular to the front surface (baffle surface) of the speaker unit, and a passive radiator 3A is attached to the partition plate 3 via a soft edge 3B.

As described above, the partition plate 3 forms one side wall of the closed acoustic space S, and on the opposite side forms one side wall of the open acoustic space S2 communicated with the outside of the speaker box 2 through the opening 4. It is.

This open acoustic space S2 functions like an acoustic duct by the action described later, that is, it guides the vibration waves output from the back surface of the speaker unit l to the front surface of the speaker box 2, and especially outputs bass reproduction. The acoustic impedance is such that waves are effectively output (in the same phase) to the front side of the speaker box 2.

The lowest resonant frequency is f of the speaker unit 1. .

In contrast, f of the passive radiator 3A. p, t”on of the open acoustic space S2 is f an< f or< f
It is set to be as. Note that the lowest resonance frequency f of the passive radiator 3A is caused by the open acoustic space S2 acting as a load. P can be effectively lowered.

The speaker system of this embodiment is configured as described above and has the features described below.

First of all, since the inside of the speaker box 2 is divided into two spaces s, , Ez via the passive radiator 3A (partition plate 3), especially when a bass audio signal is supplied to the speaker unit l, , the passive radiator 3A also vibrates in response to the amplitude of the diaphragm of the speaker unit l,
Produces the effect of increasing bass output. That is, when the diaphragm of the speaker unit l moves inward of the box, the internal pressure of the first space S1 increases, and the passive radiator 3A moves downward. Then, the internal pressure of the sealed acoustic space S1 becomes lower than the original state, and the speaker unit l
Apply a force that moves the diaphragm further inward.

Furthermore, when the diaphragm of the speaker unit 1 is driven in the direction of moving outward, the internal pressure of the sealed acoustic space S decreases,
Passive radiator 3A moves upward. Then, due to this movement, the internal pressure of the sealed acoustic space S1 increases, and a force is applied that pushes the diaphragm of the speaker unit 1 further outward.

Since such movement becomes noticeable near the resonant frequency of the passive radiator 3A, the resonant frequency f of the passive radiator 3A. P is the lowest resonant frequency f of the speaker unit l as described above. If it is set lower than 8, the conversion efficiency of the speaker unit l will improve for bass input signals,
Bass output will be enhanced.

If the passive radiator 3A has good followability with respect to the movement of the diaphragm of the speaker unit 1 (high compliance structure), the increase in the lowest resonant frequency of the speaker itself is extremely small.

Open acoustic space S2 due to vibration of passive radiator 3A
The change in the internal pressure of the speaker unit l becomes very small due to the opening 4 which is an opening to the outside, and by setting the impedance of the open acoustic space S2 to a desired value, the speaker unit l
The bass vibration waves emitted from the back surface of the passive radiator 3A and transmitted as vibration waves of the passive radiator 3A can be effectively drawn out from the opening 4 to the outside of the speaker box 2.

Also, the same acoustic space S9. Since space S* is not open and vibration waves are transmitted by the passive radiator 3A, high frequency vibration waves are effectively cut in space S2.

Next, the speaker system of the present invention particularly provides the partition plate 3 (
A passive radiator 3A) is formed in a direction perpendicular to the front surface of the speaker unit (baffle surface), and a rain space S is formed by this partition plate 3.

A major feature is that S2 is directly formed.

That is, the passive radiator 3A is not attached to the baffle surface, and only the opening 4 is required on the baffle surface other than the speaker unit 1, so that the area of the baffle plate can be significantly reduced compared to the conventional one.

In addition, by directly partitioning the rain spaces S, S, with the partition plate 3, the high-cut effect can be effectively obtained as described above.
Even without forming a long duct as in the conventional case, the open acoustic space S2 can sufficiently perform the same function as a duct or the like.

From these facts, it is possible to significantly downsize the entire speaker system.

In addition, instead of the partition plate and the passive radiator, the rain space sI is created using a vibrating membrane made of a rubber membrane or the like.

S2 may be separated.

[Effects of the Invention 1] As explained above, the speaker system of the present invention has a partition plate and a passive radiator formed in a direction perpendicular to the front surface of the speaker unit, so that the speaker box including the rear surface of the speaker unit is sealed. Since the acoustic space and the open acoustic space opened by the opening are provided, the vibration amplitude of the speaker unit can be enhanced especially in the low frequency side, thereby improving the bass reproduction ability, and making it possible to significantly improve the speaker system. It has the effect of being able to be made smaller.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of a speaker system showing an embodiment of the present invention, and FIGS. 2 and 3 are side sectional views showing examples of conventional speaker systems. 1 is a speaker unit, 2 is a speaker box, 3 is a partition plate %3A is a passive radiator, 4 is an opening, S is a closed acoustic space, and S2 is an open acoustic space. B Figure 1 X Figure 2 Figure 3

Claims (1)

[Claims] A speaker unit is provided in front of the speaker box, and a sealed acoustic space is formed in the rear space of the speaker unit by a partition plate formed in a direction perpendicular to the front surface of the speaker box and to which a passive radiator is attached, and further, the partition plate A speaker system comprising: an open acoustic space having an opening as one wall surface, and configured such that the back pressure of the passive radiator is released to the outside of the speaker box via the open acoustic space. .