JPH09331593A - Speaker equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain reproduction of a low frequency sound in a powerful, clear and articulate way by separating an inner volume of an enclosed box with a 1st speaker mounted therein into two spaces by a partition plate, mounting a 2nd speaker to the partition plate, driving the 2nd speaker and connecting a choke coil to a voice coil of the 1st speaker. SOLUTION: An inner volume of an enclosed box in which a 1st speaker 2 is mounted is separated into two spaces by a partition plate 4, a 2nd speaker 5 is mounted to the partition plate 4 and driven and a choke coil 3 is connected to a voice coil of the 1st speaker 2. When a sound amplitude change is steep in the 1st speaker 2 acting as a passive radiator, a damping current is reduced by the inductance of the choke coil 3, and when the amplitude change is slow in the case of succession of constant resonance, the damping current is increased. Thus, the speaker system reacts excellently a low frequency sound to cause less reduction in the sound pressure and attains reproduction of a low frequency sound in a powerful, clear and articulate way by applying sufficient damping to a consecutive low frequency sound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker device using a passive radiator.

[0002]

2. Description of the Related Art In recent years, a speaker device capable of reproducing heavy bass in a small space has been actively developed. Among these, there is one in which the internal volume of a closed box to which a passive radiator is attached is divided into two spaces by a partition, and a driving speaker is attached to the partition, which is called a Kelton system.

This conventional Kelton type speaker device will be described with reference to the sectional view of FIG. According to the figure, 51 is an outer wall of the closed box, 52 is a passive radiator mounted on the outer wall 51, 53 is a partition for dividing the inside of the closed box into two, 54
Is a speaker attached to the partition 53, and 55 is a speaker 5.
4 input terminals.

Next, the operation will be described. The speaker 5
When 4 is driven, the passive radiator 52 resonates at a specific frequency, and only the low sound part is radiated to the outside. This method is particularly useful for subwoofers because it has the advantages of downsizing the box and effectively cutting high frequencies.

FIG. 9 is a cross-sectional view of another conventional drone cone type speaker device. According to FIG. 9, 61 is a closed box, 62 is a driving speaker, and 63 is a speaker acting as a passive radiator. 64 is a speaker 6
A variable resistor for adjusting the braking amount, which is connected to the voice coil of No. 3, and 65 is an input terminal of the driving speaker 62.

As described above, the speaker 63 provided with the magnetic circuit is used instead of the passive radiator, and the variable resistor 64 is short-circuited to apply electromagnetic braking to emphasize the low tone and improve the response characteristic. Is.

[0007]

However, in the conventional configuration shown in FIG. 8, the passive radiator 52 itself does not have a driving force or a braking force, so that the transient response characteristic to an input signal is not good. Therefore, there are drawbacks such that the resonated vibration does not stop easily and the low tone is delayed.

Further, the one shown in FIG. 9 has a problem that the sound pressure of a low tone is simultaneously reduced by short-circuiting the variable resistor 64 and applying electromagnetic braking.

[0009]

In order to solve the above-mentioned problems, the speaker device according to the present invention divides the internal volume of the hermetically sealed box in which the first speaker is mounted into two spaces by a partition, The second speaker is mounted on the partition for driving, and the choke coil is connected to the voice coil of the first speaker.

With this configuration, in the first speaker that functions as a passive radiator, when the amplitude changes sharply, such as when the sound rises and falls, the inductance of the choke coil reduces the braking current, and a constant resonance continues. When the change is gradual, the braking current increases.

By the above, it is possible to respond well to a changing low tone and to reduce the sound pressure little, and to apply a sufficient braking to a continuous low tone to reproduce a powerful and crisp low tone.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is
The inner volume of the closed box in which the first speaker is mounted is divided into two spaces by a partition, and the partition is mounted with a second speaker for driving, and a voice coil of the first speaker is choked. In the first speaker, which acts as a passive radiator, when the amplitude of the sound changes sharply, the braking current decreases due to the inductance of the choke coil, and the amplitude changes gradually such that a constant resonance continues. In this case, the braking current will increase, and the sound pressure will be reduced well by responding well to changing bass, and sufficient braking will be applied to continuous bass to reproduce powerful and crisp bass. Is something that can be done.

According to a second aspect of the present invention, two speakers are mounted on the outer wall of one closed box to drive the first speaker, and a choke coil is connected to the voice coil of the second speaker. Thus, a drone cone type speaker device that reproduces a powerful and crisp low tone can be realized.

An embodiment of the present invention will be described below with reference to FIGS. (Embodiment 1) FIG. 1 is a sectional view of an embodiment of a speaker device of the present invention, FIGS. 2 to 4 are frequency characteristic diagrams, and FIGS. 5 and 6 are resonance characteristic diagrams.

In FIG. 1, 1 is an outer wall of the closed box, 2 is a speaker mounted on the outer wall 1, 3 is a choke coil connected to a voice coil of the speaker 2, and 4 is a partition which divides the inside of the closed box into two parts. Reference numeral 5 denotes a speaker which is a driver attached to the partition 4, and 6 denotes an input terminal of the speaker 5.

2 to 4 are frequency characteristic diagrams, FIG. 2 shows the voice coil of the speaker 2 in an open state (that is, the same as FIG. 8), and FIG. 3 shows the voice coil of the speaker 2 short-circuited. FIG. 4 shows a state in which the choke coil 3 is connected to the voice coil of the speaker 2 (this embodiment), and the speaker 5 is 400 Hz.
FIG. 6 is a frequency characteristic diagram when each sine wave of is input.

As is apparent from FIGS. 2 to 4, in contrast to FIG. 2 (the voice coil of the speaker 2 is in the open state), FIG. 3 (the voice coil of the speaker 2 is in the short state), FIG. The one in which the choke coil 3 is connected to the voice coil of the speaker 2 at the resonance point A, and the one in which the high voltage level is shown in FIG.
About 95 dB, that of FIG. 4 is about 95 dB,
The one in which the voice coil of the speaker 2 is short-circuited or the choke coil 3 is connected to the voice coil of the speaker 2 applies about 3 dB more braking than the one in which the voice coil of the speaker 2 is opened, and resonance is suppressed. I understand. In addition, B of FIGS. 2-4 has shown the impedance characteristic.

Further, FIGS. 5 and 6 are comparisons of resonance characteristics after inputting four tone burst waves (1 kHz) once.
FIG. 5 shows the case of a voice coil open pair short circuit, and FIG. 6 shows the case of a voice coil open pair (of this embodiment) choke coil connection. In both cases, the filled portion is the waveform difference from the voice coil open, and this area is the magnitude of electromagnetic braking.

That is, in the period (range T) in which the amplitude changes sharply from the resonance start of the passive radiator immediately after the tone burst, the "open-to-choke coil connection" has a smaller waveform difference than the "open-to-short" electromagnetic wave. Braking is small. After that, as the amplitude change becomes gentle, the waveform difference between the two becomes equal and electromagnetic braking approaches.

As described above, in the speaker device of this embodiment, the speaker 2 acts as a passive radiator, and its resonance state changes depending on the steepness of the amplitude change. That is, when the amplitude changes steeply, such as when the sound rises and falls, the back electromotive force of the speaker 2 changes significantly, and the inductance of the choke coil 3 reduces the braking current. Therefore, the electromagnetic braking is weak, and the speaker 2 resonates and oscillates like a conventional passive radiator.

When the change is gentle such that the constant amplitude continues, the braking current of the choke coil 3 increases.
For this reason, electromagnetic braking becomes strong and resonance of the speaker 2 is suppressed.

As a result, it is possible to respond well to a changing low tone and to reduce the sound pressure little, and to apply a sufficient braking to a low tone which is easily prone to be continuous and to reproduce a powerful low-pitched low tone.

Since the inductance of the choke coil 3 in FIG. 1 affects the change in electromagnetic braking, there is an optimum value for each system. Further, in order to reduce the loss of the braking current, it is desirable that the DC resistance is as low as possible. In the present embodiment, a coil with a ferrite core of 0.78 mH was used according to the auditory perception.

(Embodiment 2) FIG. 7 is a cross-sectional view of a speaker device according to another embodiment. The same parts as those of the embodiment of FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. Reference numeral 7 is a speaker that shares the same rear space as the speaker 2, and 8 is an input terminal of the speaker 7. In this embodiment, the present invention is applied to a general drone cone system instead of the Kelton system, and the speaker 7 works for driving. The state and action of the electromagnetic braking applied to the speaker 2 are the same as those in the first embodiment. Although the first embodiment was an improvement of the Kelton system, this embodiment reproduces a powerful low-pitched bass sound. The drone cone type speaker device can be realized.

[0025]

The speaker device of the present invention configured as described above can apply electromagnetic braking to the conventional passive radiator weakly when the amplitude change is steep and strong when the amplitude change is gentle. , It responds well to changing bass and has little reduction in sound pressure. Sufficient braking is applied to continuous bass to enable powerful and crisp bass reproduction.

[Brief description of drawings]

FIG. 1 is a sectional view of a speaker device according to an embodiment of the present invention.

FIG. 2 is a frequency characteristic diagram by a sine wave sweep in the same voice coil open state.

FIG. 3 is a frequency characteristic diagram by a sine wave sweep in the same voice coil short state.

FIG. 4 is a frequency characteristic diagram by a sine wave sweep with the choke coil connected to the voice coil.

FIG. 5 is a resonance characteristic diagram of the same tone burst (comparative example).

FIG. 6 is a resonance characteristic diagram of the same tone burst.

FIG. 7 is a sectional view of a speaker device according to another embodiment of the present invention.

FIG. 8 is a sectional view of a conventional speaker device.

FIG. 9 is a sectional view of the other speaker device.

[Explanation of symbols]

 1 Outer wall (in a closed box) 2 Speaker 3 Choke coil 4 Partition 5 Speaker 7 Speaker

Claims (2)

[Claims] 1. An internal volume of a hermetically sealed box in which a first speaker is mounted is divided into two spaces by a partition, and a second speaker is mounted in the partition for driving, and at the same time, A speaker device consisting of a choke coil connected to a voice coil. 2. A speaker device in which two speakers are mounted in one closed box to drive the first speaker and a choke coil is connected to a voice coil of the second speaker.