JPH09275595A - Sub woofer box device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain reproduction of ultra-low heavy sound and to reduce production of abnormal sound by realizing increase/decrease of a pressure caused when a chamber adopts an enclosed structure with respect to the sub woofer box device of a speaker reproducing only a low sound frequency signal. SOLUTION: A partition plate 5 with a woofer mounted thereon is used to separate the inside to be a front chamber 6 and a rear chamber 8 and one chamber is coupled with an external space with a 1st tune port 2 in anti- resonance with a specific frequency. The front and rear chambers 6, 8 are coupled with a 2nd tune port 9 fitted to the partition plate 6 having other specific anti-resonance frequency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a subwoofer box device which is used for a speaker which reproduces only a low frequency range and which is particularly suitable for an on-vehicle audio device.

[0002]

2. Description of the Related Art FIG. 8 shows a first subwoofer box device.
2A and 2B are configuration diagrams showing a conventional example of FIG. 1, in which FIG. 7A is a front view, FIG. Box body 1
A tune port 12 having a cylindrical shape is attached to the inside of the upper plate of the apparatus 1 in the longitudinal direction so as to be coupled to the outer space, and a bass speaker mounting hole 13 is formed in the front plate.

FIG. 9 is a constitutional view showing a second conventional example of a subwoofer box device, wherein (a) is a front view, (b) is a plan view, and (c) is a side sectional view. Box body 21
Similarly, a cylindrical tune port 22 is vertically installed inside the upper plate so as to be coupled to the outer space. A circular opening 23 is formed in the front plate, and a front surface of the opening 23 is formed. Is attached with a transparent plate 24.

Further, inside the box body 21, a partition plate 2 for setting two front and rear chambers 25 and 26 is provided.
7 is attached, and a bass speaker attachment hole 28 is formed in the center of the partition plate 27.

[0005]

However, the above-mentioned first problem
In the conventional example (Fig. 8), when a speaker for low-pitched sound reproduction is attached, the front surface of the diaphragm is exposed to the outside of the box body 11, so that there is a disadvantage that unnecessary sounds in the middle range are easily reproduced as a subwoofer. is there.

Further, when a grill net or the like is attached to protect the exposed diaphragm, the appearance of the diaphragm becomes difficult to see, but it is also an important factor to show the inside of an audio device mounted on a vehicle. Will be at a disadvantage.

In the above-mentioned second conventional example (FIG. 9), when the bass reproduction speaker is attached to the speaker attachment hole 28 provided in the partition plate 27 and the transparent plate 24 is attached to the front plate, the speaker is front and rear respectively. Independent chambers 25, 26
Since it is built in the box body 21 having a low pass filter, the mid-high range can be attenuated. Further, since the external appearance of the diaphragm can be seen well through the transparent plate 24, it is suitable for use in a vehicle-mounted audio device.

However, when the outer dimensions of the box main body 21 are the same as those of the first conventional example, the front chamber 25 is in a closed state with a small volume, so that the pressure is excessively increased or decreased and the amplitude of the speaker diaphragm is increased. It is held down, and it is difficult to reproduce deep bass. Further, there is an inconvenience that an abnormal sound is likely to occur due to a rapid increase or decrease in pressure.

The present invention has been made in order to solve such a conventional problem, and makes it possible to reproduce deep bass sound by mitigating the increase and decrease in pressure that occurs when the chamber has a closed structure, and further The purpose is to reduce the occurrence.

[0010]

In the subwoofer box device of the present invention, a partition plate to which a bass speaker is attached divides the interior into a front chamber and a rear chamber, and one chamber is antiresonant at a specific frequency.
Has a structure in which the front chamber and the rear chamber are coupled to each other with a second tune port having another specific anti-resonance frequency attached to the partition plate.

According to the present invention, by forming a low-pass filter, the mid-high range is attenuated, and furthermore, the increase and decrease of the pressure in the sealed chamber is alleviated to enable the reproduction of deep bass sound, and further abnormal sound is generated. A subwoofer box device that can be reduced is obtained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is divided into a front chamber and a rear chamber by a partition plate to which a bass speaker is attached, and one chamber is antiresonant at a specific frequency. And the front chamber and the rear chamber are connected to each other by a second tune port having another specific anti-resonance frequency attached to the partition plate.

According to the second aspect of the present invention, the specific anti-resonance frequency of the second tune port is determined by the respective inner volumes of the front chamber and the rear chamber and the inner diameter and the length of the second tune port. The subwoofer box device is a frequency that becomes an anti-resonance frequency in the entire system of the subwoofer box.

According to the present invention, by connecting a second tune port between the front chamber and the rear chamber, the specific volume determined by the inner volume of the front and rear chambers and the inner diameter and length of the tune port. At the anti-resonance frequency, the movement of the diaphragm of the speaker becomes minute and the internal pressure does not rise sharply. Further, at frequencies around the specific anti-resonance frequency, the air in the chambers before and after goes in and out of the second tune port, so there is no sudden increase in the internal pressure,
It is possible to realize deep bass reproduction and reduce the generation of abnormal sound from the speaker or box body.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a subwoofer box device according to an embodiment of the present invention, in which (a) is a front view, (b) is a plan view, and (c) is a side sectional view.
In this device, a first tune port 2 is attached to an upper plate of a box body 1 by being vertically connected to an external space, and a circular opening 3 is formed in a front plate. This hole 3
A transparent plate 4 is fixed to the box main body 1 by a screw or the like on the front surface thereof, and forms a front chamber 6 together with a partition plate 5 attached inside the box main body 1.

The partition plate 5 is fixed to the inner wall of the box body 1 so that air does not leak, and a bass speaker mounting hole 7 is formed in the center thereof. A rear chamber 8 is formed by the partition plate 5 and the rear half of the box body 1.

Further, at the lower left of the front surface of the partition plate 5, a cylindrical second tune port 9 for connecting the front chamber 6 and the rear chamber 8 is provided adjacent to the bass speaker mounting hole 7.
Are installed in the front-back direction.

In this structure, when a signal is input to the low-pitched speaker (not shown) attached to the partition plate 5 and the diaphragm of the speaker oscillates back and forth, the air in the front chamber 6 and the rear chamber 8 becomes the second. Enter and exit through tune port 9. At a specific frequency fR1 determined by the volume of the front chamber 6, the volume of the rear chamber 8, the inner diameter and the length of the tune port 9, the speaker diaphragm has a small amplitude, and the front and rear chambers 6 and 8 are tuned. A compression wave of air, that is, a sound is emitted from the tip of the port 9. The specific frequency fR1 becomes an anti-resonance frequency in the system of the entire subwoofer box.

The compressional wave of air radiated from the tune port 9 has the same phase as the speaker diaphragm in the front and rear chambers 6 and 8. As the frequency becomes higher than the anti-resonance frequency fR1, the phase shifts and cancels a part of the compression wave of the air emitted by the diaphragm of the speaker. The same applies to frequencies lower than the anti-resonance frequency fR1.

At frequencies near the anti-resonance frequency fR1, conversely the compressional wave of air radiated from the speaker diaphragm is strengthened. The rear chamber 8 radiates from the tune port 2 a compression wave of air radiated from the back surface of the speaker diaphragm and a compression wave of air that is a combination of compression waves of air radiated from the tune port 9.

At a frequency near the anti-resonance frequency fR2 determined by the inner diameter and length of the first tune port 2 and the volume of the rear chamber 8, the compression wave of air is intensified and radiated from the tune port 2. To be done. At this time, the sound in the mid-high range is greatly attenuated.

Next, the frequency characteristics of the subwoofer box device according to this embodiment will be described. 2 to 5
FIG. 4 is a diagram showing an output sound pressure frequency characteristic (hereinafter referred to as F characteristic) and an impedance characteristic when the anti-resonance frequency fR1 of the tune port 9 is changed.

In the subwoofer box device used for the measurement this time, the inner volume of the front chamber 6 is about 14 liters, and the inner volume of the rear chamber 8 is about 14 liters (however, the volume occupied by the bass speaker is the tune port 2). , Except that the anti-resonance frequency of the first tune port 2 is about 65 Hz (inner diameter φ80, length 190 mm).

In this measurement, the second tune port 9
Is a cylindrical paper with an outer diameter of φ60 and an inner diameter of φ50, and its length is three types of 60 mm, 120 mm, and 190 mm. Also,
If the tune port 9 has an inner diameter of 60 and a length of 20 mm,
The tune port 9 is removed from the partition plate 5, and a mounting hole φ60 and a plate pressure of 20 mm are used as the tune port inner diameter and length. If there is no tune port 9,
Another plate was attached to the tune port mounting hole of the partition plate 5 for measurement.

In FIG. 2, the second tune port 9 has an outer diameter φ.
The characteristics in the case of 60 and the length of 20 mm are shown. In this case, the antiresonance frequency fR1 is 66 Hz and the antiresonance frequency fR2 is 65H.
z. The sound pressure drops at 50 to 150 Hz, and the audibility is poor. However, there is a bass extension. Looking at the impedance curve, the amplitude around 25 Hz is too large.

In FIG. 3, the second tune port 9 has an outer diameter φ.
The characteristics when 50 and 60 mm in length are shown. In this case, the antiresonance frequency fR1 is 46Hz and the antiresonance frequency fR2 is 65H.
z. Although the drop in sound pressure is improved, the impedance curve shows that the amplitude around 20 Hz is too large.

In FIG. 4, the second tune port 9 has an outer diameter φ.
The characteristics when 50 and 120 mm in length are shown. in this case,
Anti-resonance frequency fR1 is 36 Hz, anti-resonance frequency fR2 is 65
Hz. Sound pressure drop is further improved, 20
The sound pressure at 40 Hz is rising. Looking at the impedance curve, the amplitude near 20 Hz is also suppressed.

In FIG. 5, the second tune port 9 has an outer diameter φ.
The characteristics when 50 and 190 mm in length are shown. in this case,
Anti-resonance frequency fR1 is 30Hz, anti-resonance frequency fR2 is 65
Hz. The sound pressure of 20-40 Hz is increasing. Although the user perceives a very low sound, the connection with the sound of 50 to 100 Hz is not good.

In the measurement by this experiment, the case where the anti-resonance frequency fR1 of the second tune port 9 was about 36 Hz was the best (FIG. 4). The condition of anti-resonance frequency fR1 must be lower than anti-resonance frequency fR2.
About half of R2 seems to be good in operation. However, the optimum value of the anti-resonance frequency fR2 cannot be determined only by the subwoofer box itself because various constants of the speaker also influence.

FIG. 6 shows the F characteristic of the second conventional device (FIG. 9) in the case where the second tune port 9 is not provided. In this case, the antiresonance frequency fR2 is 65 Hz. Although the F characteristic is good, it is a sound that is hard to hear and does not stretch, and abnormal noise is often generated.

FIG. 7 shows the F characteristic of the second conventional apparatus (FIG. 9) shown in FIG. 6 by a broken line, and the outer diameter φ5 shown in FIG.
The F characteristic of the device of the present invention having a tune port 9 of 0 and a length of 120 mm is shown by a solid line. Comparing the two devices, it can be seen that the sound pressure of 25 to 40 Hz is increased in the device of the present invention.

As described above, according to the present embodiment, by connecting the front chamber 6 and the rear chamber 8 with the tune port 9, the reproduction of the low frequency range is expanded and the generation of the abnormal sound is reduced. Have advantages.

Although the first tune port 2 is attached to the rear chamber 8 in the above embodiment, it may be attached to the front chamber 6. Also, tune port 2
Although cylindrical paper is used for 9 and 9, the material may be resin or the like, and the shape is not limited to a cylindrical shape, and may be a rectangular tube shape.
Further, the partition plate 5 and the subwoofer box body 1 may form the second tune port 9 in a slit shape.
The same applies to the first tune port 2.

[0034]

According to the present invention, since the front chamber and the rear chamber are connected by the second tune port,
At low frequencies, low frequency reproduction can be expanded without disturbing the amplitude operation of the speaker diaphragm. Further, it is possible to reduce the abnormal sound of the speaker or the subwoofer main body caused by the sudden increase and decrease of the pressure. In addition, since the subwoofer box device forms a low-pass filter, it is possible to attenuate unnecessary mid frequencies in the low-frequency reproduction device.

[Brief description of drawings]

FIG. 1 is a front view, a plan view and a side sectional view of a subwoofer box device according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing output sound pressure frequency characteristics and impedance characteristics of the subwoofer box device according to the same embodiment.

FIG. 3 is a characteristic diagram showing output sound pressure frequency characteristics and impedance characteristics of the subwoofer box device according to the same embodiment.

FIG. 4 is a characteristic diagram showing output sound pressure frequency characteristics and impedance characteristics of the subwoofer box device according to the same embodiment.

FIG. 5 is a characteristic diagram showing output sound pressure frequency characteristics and impedance characteristics of the subwoofer box device according to the same embodiment.

FIG. 6 is a characteristic diagram showing output sound pressure frequency characteristics and impedance characteristics of a conventional device without the second tune port shown in FIG.

FIG. 7 shows the output sound pressure frequency characteristic (solid line) shown in FIG. 4 and FIG.
Figure comparing output sound pressure frequency characteristics (dashed line) shown in

FIG. 8 is a front view, a plan view and a side sectional view of a subwoofer box device showing a first conventional example.

FIG. 9 is a front view, a plan view and a side sectional view of a subwoofer box device showing a second conventional example.

[Explanation of symbols]

 1 Box Main Body 2 First Tune Port 3 Opening Hole 4 Transparent Plate 5 Partition Plate 6 Front Chamber 7 Bass Speaker Mounting Hole 8 Rear Chamber 9 Second Tune Port

Claims (2)

[Claims] 1. A partition plate to which a bass speaker is attached divides the interior into a front chamber and a rear chamber, and one chamber is coupled to an outer space by a first tune port that is anti-resonant at a specific frequency, and the front chamber and The subwoofer box device, wherein the rear chamber is coupled with a second tune port having another specific anti-resonance frequency attached to the partition plate. 2. The specific anti-resonance frequency of the second tune port is determined by the inner volume of each of the front chamber and the rear chamber and the inner diameter and length of the second tune port, and in the system of the entire subwoofer box. A frequency which is an anti-resonance frequency.
The described subwoofer box device.