JP3687180B2 - Subwoofer box device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a subwoofer box device that is used for a speaker that reproduces only a low sound range, and is particularly suitable for an on-vehicle audio device.
[0002]
[Prior art]
8A and 8B are configuration diagrams showing a first conventional example of the subwoofer box device, in which FIG. 8A is a front view, FIG. 8B is a plan view, and FIG. 8C is a side sectional view. A cylindrical tune port 12 is attached to the upper plate of the box main body 11 while being coupled to the outer space in the vertical direction, and a bass speaker mounting hole 13 is formed in the front plate.
[0003]
FIG. 9 is a block diagram showing a second conventional example of the subwoofer box device, where (a) is a front view, (b) is a plan view, and (c) is a side sectional view. Similarly, a cylindrical tune port 22 is attached to the upper plate of the box body 21 in the longitudinal direction and connected to the outer space, and a circular opening 23 is formed in the front plate. A transparent plate 24 is attached to the front surface of.
[0004]
Further, a partition plate 27 for setting the front and rear chambers 25 and 26 is attached inside the box body 21, and a bass speaker mounting hole 28 is formed in the center of the partition plate 27. .
[0005]
[Problems to be solved by the invention]
However, in the above-described first conventional example (FIG. 8), when a low-frequency sound reproducing speaker is attached, the front surface of the diaphragm is exposed to the outside of the box body 11, so that a mid-range sound unnecessary for a subwoofer is generated. There is an inconvenience of being easily reproduced.
[0006]
Also, if a grill net or the like is attached to protect the exposed diaphragm, it will be difficult to see the appearance of the diaphragm, but it is also an important factor to show the inside of the in-vehicle audio device, which is disadvantageous. Become.
[0007]
In the above-described second conventional example (FIG. 9), when a low-pitched sound 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 speakers are separated into front and rear chambers. Since it is built in the box body 21 having 25 and 26 and a low-pass filter is formed, the mid-high range can be attenuated. Further, since the appearance of the diaphragm can be seen well through the transparent plate 24, it is suitable for use in an in-vehicle audio apparatus.
[0008]
However, when the outer dimensions of the box body 21 are the same as those of the first conventional example, the front chamber 25 is in a sealed state with a small volume, so that the pressure increases and decreases excessively, and the amplitude of the diaphragm of the speaker is suppressed. Heavy bass reproduction is difficult. Moreover, there is an inconvenience that abnormal noise tends to occur due to a sudden increase or decrease in pressure.
[0009]
The present invention has been made to solve such a conventional problem, and enables the reproduction of heavy bass by reducing the pressure increase / decrease occurring when the chamber has a sealed structure, and further reduces the occurrence of abnormal sounds. The purpose is to do.
[0010]
[Means for Solving the Problems]
In the subwoofer device of the present invention, the interior is divided into a front chamber and a rear chamber by a partition plate to which a bass speaker is attached, the front chamber is provided with a transparent front plate, and the interior and the outer space of the rear chamber are the first space Coupled with a tune port, a bass speaker is attached to the front chamber, and the front chamber and the rear chamber have a structure coupled with a second tune port attached to the partition plate.
[0011]
According to the present invention, a subwoofer capable of attenuating the mid-high range by forming a low-pass filter, enabling the reproduction of heavy bass by relaxing the increase and decrease of the pressure in the sealed chamber, and further reducing the occurrence of abnormal sounds. A box device is obtained.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
According to the first aspect of the present invention, the interior is divided into a front chamber and a rear chamber by a partition plate to which a bass speaker is attached, and the front chamber includes a transparent front plate, and the inside and the outside of the rear chamber The space is connected by a first tune port, a bass speaker is attached to the front chamber, and the front chamber and the rear chamber are connected by a second tune port attached to the partition plate.
[0013]
Invention according to claim 2, wherein the specific anti-resonance frequency of the second tune port, determine a respective inner volume of the front chamber and the rear chamber, the inner diameter and length of the second tune port The in- vehicle subwoofer box device according to claim 1 , wherein the mid-high range is attenuated .
[0014]
According to the present invention, the specific anti-resonance frequency determined by the inner volume of the front and rear chambers and the inner diameter and length of the tune port by connecting the front chamber and the rear chamber with the second tune port. Then, the movement of the diaphragm of the speaker becomes very small, and the internal pressure does not increase rapidly. In addition, at the frequencies before and after the specific anti-resonance frequency, the air in the front and rear chambers enters and exits at the second tune port, so that the internal pressure does not increase suddenly, and a heavy bass reproduction can be realized. Generation of abnormal noise from the main body can be reduced.
[0015]
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, where (a) is a front view, (b) is a plan view, and (c) is a side sectional view. In this apparatus, a first tune port 2 is attached to the upper plate of the box body 1 while being connected to the external space in the vertical direction, and a circular opening 3 is formed in the front plate. A transparent plate 4 is fixed to the box body 1 with screws or the like on the front surface of the opening 3, and a front chamber 6 is formed together with a partition plate 5 attached to the inside of the box body 1.
[0016]
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. A rear chamber 8 is formed by the partition plate 5 and the rear half of the box body 1.
[0017]
In addition, a cylindrical second tune port 9 for connecting the front chamber 6 and the rear chamber 8 adjacent to the bass speaker mounting hole 7 is installed in the front left and lower sides of the partition plate 5 in the front-rear direction. Yes.
[0018]
In this configuration, when a signal is input to a low-frequency speaker (not shown) attached to the partition plate 5 and the diaphragm of the speaker swings back and forth, the air in the front chamber 6 and the rear chamber 8 is supplied to the second tune port 9. Go in and out. 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 amplitude of the speaker diaphragm becomes minute, and the tunes are respectively made in the front and rear chambers 6 and 8. An air dense wave, that is, a sound is emitted from the tip of the port 9. The specific frequency fR1 is an anti-resonance frequency in the entire system of the subwoofer box.
[0019]
The air density wave radiated from the tune port 9 is in phase with 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 a part of the air dense wave radiated by the diaphragm of the speaker is canceled. The same applies to frequencies lower than the antiresonance frequency fR1.
[0020]
On the other hand, at a frequency in the vicinity of the anti-resonance frequency fR1, the dense wave of air radiated from the speaker diaphragm is strengthened. The rear chamber 8 radiates an air dense wave radiated from the rear surface of the speaker diaphragm and an air dense wave synthesized from the tune port 9 and radiated from the tune port 2.
[0021]
Further, at a frequency in the vicinity of 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 air density wave is intensified and radiated from the tune port 2. At this time, the mid-high range sound is greatly attenuated.
[0022]
Next, frequency characteristics of the subwoofer box device according to the present embodiment will be described. 2 to 5 are diagrams showing output sound pressure frequency characteristics (hereinafter referred to as F characteristics) and impedance characteristics when the anti-resonance frequency fR1 of the tune port 9 is changed.
[0023]
The subwoofer box device used for the measurement this time has an inner volume of the front chamber 6 of about 14 liters and an inner volume of the rear chamber 8 of about 14 liters (however, the volume occupied by the bass speaker is the volume occupied by the tune port 2). The anti-resonance frequency of the first tune port 2 is about 65 Hz (inner diameter φ80, length 190 mm).
[0024]
In this measurement, the second tune port 9 is a cylindrical paper having an outer diameter of φ60 and an inner diameter of φ50, and the lengths are three types of 60 mm, 120 mm, and 190 mm. When the tune port 9 has an inner diameter φ60 and a length of 20 mm, the tune port 9 is removed from the partition plate 5, and the mounting hole φ60 and the plate pressure 20 mm are the inner diameter and length of the tune port. When there was no tune port 9, another plate was attached to the tune port mounting hole of the partition plate 5 for measurement.
[0025]
FIG. 2 shows the characteristics when the second tune port 9 has an outer diameter φ60 and a length of 20 mm. In this case, the antiresonance frequency fR1 is 66 Hz, and the antiresonance frequency fR2 is 65 Hz. The sound pressure drops at 50 to 150 Hz, and the sound is not strong. However, there is an increase in bass. Even when looking at the impedance curve, the amplitude around 25 Hz is too large.
[0026]
FIG. 3 shows the characteristics when the second tune port 9 has an outer diameter φ50 and a length of 60 mm. In this case, the antiresonance frequency fR1 is 46 Hz and the antiresonance frequency fR2 is 65 Hz. Although the drop in sound pressure has been improved, the amplitude around 20 Hz is too large according to the impedance curve.
[0027]
FIG. 4 shows the characteristics when the second tune port 9 has an outer diameter φ50 and a length of 120 mm. In this case, the antiresonance frequency fR1 is 36 Hz, and the antiresonance frequency fR2 is 65 Hz. The drop in sound pressure is further improved, and the sound pressure at 20 to 40 Hz is increased. Looking at the impedance curve, the amplitude near 20 Hz is also suppressed.
[0028]
FIG. 5 shows the characteristics when the second tune port 9 has an outer diameter of 50 and a length of 190 mm. In this case, the antiresonance frequency fR1 is 30 Hz, and the antiresonance frequency fR2 is 65 Hz. The sound pressure of 20-40 Hz is rising. In terms of hearing, a very low sound is felt, but the connection with the sound of 50 to 100 Hz is not good.
[0029]
In the measurement by this experiment, it was the best when the anti-resonance frequency fR1 of the second tune port 9 was about 36 Hz (FIG. 4). The condition of the anti-resonance frequency fR1 needs to be lower than the anti-resonance frequency fR2, and about half of the anti-resonance frequency fR2 seems to be good in operation. However, the optimum value of the anti-resonance frequency fR2 is influenced by various constants of the speaker, and cannot be determined only by the subwoofer box itself.
[0030]
FIG. 6 shows the F characteristics of the second conventional apparatus (FIG. 9) when the second tune port 9 is not provided. In this case, the antiresonance frequency fR2 is 65 Hz. Although the F characteristic is good, the sound is hard and does not stretch, and abnormal sounds are often generated.
[0031]
FIG. 7 shows the F characteristic of the second prior art device shown in FIG. 6 (FIG. 9) by a broken line, and the F characteristic of the device of the present invention having the tune port 9 of outer diameter φ50 and length 120 mm shown in FIG. Is shown by a solid line. When both devices are compared, it can be seen that the sound pressure of 25 to 40 Hz is increased in the device of the present invention.
[0032]
As described above, according to the present embodiment, the front chamber 6 and the rear chamber 8 are coupled by the tune port 9, thereby having the advantage of expanding the reproduction of the low frequency range and reducing the occurrence of abnormal sounds. .
[0033]
In the embodiment described above, the first tune port 2 is attached to the rear chamber 8 . Moreover, although cylindrical paper is used for the tune ports 2 and 9, a material such as resin may be used, and the shape is not limited to the cylindrical shape, and may be a square cylindrical shape. Further, the second tune port 9 may be formed in a slit shape by the partition plate 5 and the subwoofer box body 1. The same applies to the first tune port 2.
[0034]
【The invention's effect】
According to the present invention, since the front chamber and the rear chamber are coupled by the second tune port, low-frequency reproduction can be expanded without impeding the amplitude operation of the speaker diaphragm at a low frequency. In addition, the abnormal sound of the speaker or subwoofer main body generated by a sudden increase or decrease in pressure can be reduced. Further, since the subwoofer box device forms a low-pass filter, the low-frequency reproduction apparatus capable of attenuating the high-mids unnecessary.
[Brief description of the 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 embodiment. FIG. 3 is a characteristic diagram showing output sound pressure frequency characteristics and impedance characteristics of the subwoofer box device according to the embodiment. FIG. 4 is a characteristic diagram showing output sound pressure frequency characteristics and impedance characteristics of the subwoofer box device according to the embodiment. 5 is a characteristic diagram showing an output sound pressure frequency characteristic and an impedance characteristic of the subwoofer box device according to the embodiment; FIG. 6 is an output sound pressure frequency characteristic of a conventional apparatus without the second tune port shown in FIG. FIG. 7 is a characteristic diagram showing impedance characteristics. FIG. 7 is an output sound pressure frequency characteristic (solid line) shown in FIG. 4 and FIG. 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 subwoofer box showing a second conventional example. Front view, plan view, and side cross-sectional view of the device
1 Box 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)

The interior is divided into a front chamber and a rear chamber by a partition plate to which a bass speaker is attached, the front chamber is provided with a transparent front plate, and the interior and the outer space of the rear chamber are coupled by a first tune port, A subwoofer box device , wherein a bass speaker is attached to a front chamber, and the front chamber and the rear chamber are coupled by a second tune port attached to the partition plate. Specific anti-resonance frequency of the second tune port, said each internal volume of the front chamber and the rear chamber is determined by the inner diameter and length of the second tune port, to attenuate the mid-high range The in-vehicle subwoofer box device according to claim 1.

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