JP2784063B2 - Bass stereo playback device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stereo reproduction apparatus, and more particularly to a low-frequency stereo reproduction apparatus that selectively reproduces low-frequency sound in stereo.

[Prior Art] FIG. 5 is a plan sectional view of a conventional bass stereo reproduction apparatus. The bass stereo playback device is the L channel playback device 1
And an R channel reproducing device 2. The L-channel playback device 1 includes a cabin net 3, a speaker 4, and an acoustic filter 5.

Cabinet 3 is a closed cabinet. One of the side walls constituting the cabinet 3 is provided with a speaker mounting opening 6. The speaker 4 is attached to the speaker opening 6. The speaker 4 is mounted so that the front surface of the speaker 4 is exposed outside the cabinet 3.

When the closed type is used as the cabinet 3, there are the following advantages. When the sound is heard from the front of the speaker 4, when the sound wave reaches the front from the back, the sound interferes with the sound from the front and cancels each other, so that the sound is reduced. This tendency is remarkable in the bass range. When a closed type cabinet is used as the cabinet 3, such a phenomenon can be prevented because the sound waves from the back surface are enclosed in the cabinet 3.

The acoustic filter 5 includes a box 11 and a duct 12. By appropriately designing the length of the duct, the cross-sectional area of the duct, and the volume of the box portion excluding the duct, the acoustic filter 5 can selectively pass a required low-tone range.

The structure of the R-channel playback device 2 is the same as that of the L-channel playback device 1, and a description thereof is omitted. However, an R channel signal is input to the speaker 4 of the R channel reproducing device 2.

[Problems to be Solved by the Invention] However, in the conventional system shown in FIG. 5, if the volume of the closed cabinet 3 provided on the rear side of the speaker 4 is not sufficiently large, the bass reproduction band can be reduced to a sufficiently low band. However, there is a problem that it is difficult to increase the sound pressure to a maximum, or the sound pressure level in a low sound range becomes low.

In order to solve such a problem, the sixth
There is a bass reproduction device as shown in the figure. This bass reproduction device is a cabinet common to the cabinet of the first channel reproduction device and the cabinet of the second channel reproduction device. Hereinafter, the bass reproducing apparatus will be described. This bass reproduction device has a cabinet 15, speakers
16, 17 and an acoustic filter 18.

Cabinet 15 is a closed cabinet. One of the side walls constituting the cabinet 15 is provided with speaker mounting openings 19 and 20. The speaker 16 is mounted in the speaker mounting opening 19. Speaker 16 is mounted such that the front surface of speaker 16 is exposed outside cabinet 15. An L channel signal is input to the speaker 16. The speaker 17 is attached to the speaker attachment opening 20. Speaker 17 is mounted such that the front surface of speaker 17 is exposed outside cabinet 15. An R channel signal is input to the speaker 17.

 The acoustic filter 18 includes a box 29 and a duct 30.

In the bass reproduction apparatus shown in FIG.
The cabinet accommodating 16 and the cabinet accommodating the speaker 17 are a common cabinet 15.
For example, when the volume of the cabinet 15 is the cabinet 3 of the L channel reproduction device of the bass stereo reproduction device shown in FIG.
If the low-frequency signal is input to only one of the channels, the bass sound reproducing device shown in FIG. The reproduction limit frequency can be lower than that of the bass stereo reproduction device shown.

However, in the bass reproducing apparatus shown in FIG. 6, both the sound wave emitted from the speaker 16 and the sound wave emitted from the speaker 17 pass through the acoustic filter 18. For this reason, the sound wave coming out of the sound wave emission port 31 becomes monaural, and stereo reproduction cannot be performed.

Therefore, the present invention has been made to solve such a conventional problem. SUMMARY OF THE INVENTION An object of the present invention is to provide a low-frequency stereo reproduction apparatus capable of performing stereo reproduction and lowering a reproduction limit frequency.

[Means for Solving the Problems] A bass stereo playback device according to the present invention has a first channel playback device and a second channel playback device.

The first channel playback device is provided so as to connect a first cabinet to which a speaker for converting a first channel signal into a sound wave is attached, with the first box, and inside and outside of the first box. A first acoustic filter having a first cylindrical opening provided.

The second channel playback device is provided so as to communicate a second cabinet to which a speaker for converting a second channel signal into a sound wave is attached, a second box portion, and the inside and outside of the second box portion. A second acoustic filter having a second cylindrical opening provided.

In the bass stereo reproduction device according to the present invention, the volume of the first box of the first acoustic filter, the opening area of the first cylindrical opening, and the length of the first cylindrical opening are each The volume of the second box of the second acoustic filter, the opening area of the second cylindrical opening, and the length of the second cylindrical opening are substantially equal to each other; Is connected to the second cabinet of the second channel playback device.

[Operation] In the bass reproduction device according to the present invention, the cabinet of the first channel reproduction device and the cabinet of the second channel reproduction device communicate with each other. Therefore, the speaker of the first channel playback device is accommodated in a cabinet having a size obtained by adding the cabinet of the first channel playback device and the cabinet of the second channel playback device. For this reason, the volume of the cabinet of the first channel reproduction device of the bass stereo reproduction device according to the present invention is larger than the volume of the cabinet of the first channel reproduction device of the conventional bass stereo reproduction device shown in FIG. Become. For this reason, the reproduction limit frequency of the first channel reproduction device of the bass stereo reproduction device according to the present invention is such that when a low frequency signal is input only to this channel, the conventional bass stereo reproduction device shown in FIG. It becomes lower than the reproduction limit frequency of the first channel reproduction device of the device. The same applies to the second channel playback device of the bass stereo playback device according to the present invention.

Further, in the bass stereo reproduction device according to the present invention, the acoustic filter provided in the first channel reproduction device and the acoustic filter provided in the second channel reproduction device are designed to be the same and separate from each other. It becomes possible.

FIG. 1 is a plan sectional view of a first embodiment of a bass stereo reproduction apparatus according to the present invention. The first embodiment of the bass stereo reproducing apparatus according to the present invention includes a cabinet 41, speakers 42 and 43, and acoustic filters 44 and 45.

The cabinet 41 is a closed cabinet. One of the side walls constituting the cabinet 41 is provided with speaker mounting openings 46 and 47.

The speaker 42 is mounted in the speaker mounting opening 46. The speaker 42 is mounted such that the front surface of the speaker 42 is exposed outside the cabinet 41. Speaker 42 is L
Play the channel.

The speaker 43 is attached to the speaker attachment opening 47. The speaker 43 is mounted such that the front surface of the speaker 43 is exposed outside the cabinet 41. Speaker 43 is R
Play the channel.

The acoustic filter 44 includes a box 56 and a duct 57. The acoustic filter 44 is designed to selectively pass a necessary bass range. The cabinet 41, the speaker 42, and the acoustic filter 44 constitute an L-channel playback device.

The acoustic filter 45 includes a box portion 59 and a duct 60. The acoustic filter 45 is designed to be equivalent to the acoustic filter 44.
The cabinet 41, the speaker 43, and the acoustic filter 45 constitute an R-channel playback device. Acoustic filter 44 and acoustic filter
45 has a common side wall 62.

In this embodiment, the cabinet 41 is shared by the L-channel playback device and the R-channel playback device.
Therefore, the volume of the cabinet 41 is the sum of the volume of the cabinet 3 of the L-channel reproduction device of the conventional bass stereo reproduction device and the volume of the cabinet 3 of the R-channel reproduction device shown in FIG. Therefore,
According to this embodiment, when a low-frequency signal is input to only one of the channels, the reproduction limit frequency can be reduced as compared with the conventional bass stereo reproduction device shown in FIG. The sound wave radiated from the speaker 42 for reproducing the L channel passes through the acoustic filter 44. The sound wave radiated from the speaker 43 for reproducing the R channel passes through the acoustic filter 45. Therefore, according to this embodiment, stereo reproduction becomes possible.

A second embodiment of the bass stereo reproduction apparatus according to the present invention will be described. FIG. 2 is a plan sectional view of a second embodiment of the bass stereo reproduction apparatus according to the present invention. The difference from the first embodiment is that the cabinet 41 has a partition plate 66 having an opening 67.
That is, As a result, the cabinet 41 is divided into an L-channel cabinet 68 and an R-channel cabinet 69.
43 becomes the same as sharing a cabinet.

A third embodiment of the bass stereo reproduction apparatus according to the present invention will be described. FIG. 3 is a plan sectional view of a third embodiment of the bass stereo reproduction apparatus according to the present invention. The third embodiment of the bass stereo reproduction apparatus according to the present invention includes a cabinet 71, speakers 72 and 73, and acoustic filters 74 and 75.

Speaker mounting openings 76 and 7 are provided on the side wall of cabinet 71.
7. An opening 78 is provided. A speaker 72 is mounted in the speaker mounting opening 76. The speaker 72 receives an L channel signal. The speaker 73 is attached to the speaker attachment opening 77. An R channel signal is input to the speaker 73.

Acoustic filters 74 and 75 are attached to the side walls of the cabinet 71 where the speaker mounting openings 76 and 77 and the opening 78 are provided. The acoustic filter 74 includes a box 87 and a duct 88. One end of the duct 88 is a sound wave emission port 89. Acoustic filter 75 is box part 90,
And a duct 91. One end of the duct 91 is a sound wave emission port 92. The sound wave emitted from the speaker 72 passes through the acoustic filter 74. The sound wave emitted from the speaker 73 passes through the acoustic filter 75. The cabinet 71 has a phase inversion type cabinet structure,
A duct 95 is attached to the opening 78 of the 71. cabinet
An acoustic filter 97 is formed by 71 and the duct 95.

Resonance frequency of acoustic filters 74 and 75 to about 150Hz,
The state of the sound pressure characteristic of an example in which the resonance frequency of the acoustic filter 97 is designed to be about 50 Hz will be described.

FIG. 4 is a graph showing the relationship between the frequency (Hz) and the relative sound pressure level (dB) of the third embodiment of the bass stereo reproduction apparatus according to the present invention. The relationship between the frequency of the sound wave radiated from the acoustic filters 74 and 75 and the relative sound pressure level is represented by the curve a. The relationship between the frequency of the sound wave radiated from the acoustic filter 97 and the relative sound pressure level is represented by a curve indicated by b. The curve indicated by c represents the sum of the curve indicated by a and the curve indicated by b in consideration of the phase component, that is, the relationship between the frequency of the low-frequency stereo reproduction apparatus and the relative sound pressure level.

As shown in Fig. 4, the sound wave near 50Hz is a sound wave emission port.
Emitted mainly from 96. Sound waves of 60 to 300 Hz are mainly emitted from the sound wave emission ports 89 and 92.

Therefore, according to the third embodiment, a sound wave of a relatively high frequency, which makes it easy to recognize the localization (the direction of the sound image) among the low sounds, is reproduced in stereo from the sound wave emission ports 89 and 92. Also, among the low-pitched sounds, a sound wave of a relatively low frequency for which it is difficult to recognize the localization is reproduced in monaural from the sound wave emission port 96.

In the third embodiment, since the duct 95 is attached to the cabinet 71, the cabinet 71 functions as a phase inversion type cabinet. For this reason, in the third embodiment, the sound pressure level near the low-frequency limit frequency is higher than in the case of using a closed cabinet, and bass can be effectively reproduced.

As another cabinet that can be used in the third embodiment, there is a cabinet of a passive radiator type.

In the first, second, and third embodiments, 2-channel stereo reproduction is used. However, the present invention is not limited to this, and 3-channel stereo reproduction or 4-channel stereo reproduction may be used.

[Effect] In the bass stereo reproduction device according to the present invention, the cabinet of the first channel reproduction device and the cabinet of the second channel reproduction device are communicated. Therefore, the speaker of the first channel playback device is accommodated in a cabinet having a size obtained by adding the cabinet of the first channel playback device and the cabinet of the second channel playback device. For this reason, the cabinet volume of the first channel reproduction device of the bass stereo reproduction device according to the present invention is larger than the cabinet volume of the first channel reproduction device of the conventional bass stereo reproduction device. For this reason, the reproduction limit frequency of the first channel reproduction device of the bass stereo reproduction device according to the present invention is such that when a low-frequency signal is input only to the first channel, the first bass reproduction device of the conventional bass stereo reproduction device. The frequency becomes lower than the reproduction limit frequency of the channel reproducing apparatus, and effective sound can be reproduced even with a sound having a lower frequency. The same applies to the second channel playback device of the bass stereo playback device according to the present invention.

The bass stereo reproduction apparatus according to the present invention is the first stereo reproduction apparatus.
Filter provided in the channel reproduction device of
Since the acoustic filters provided in the channel reproducing device are designed and separated from each other, stereo reproduction is possible.

[Brief description of the drawings]

FIG. 1 shows a bass stereo reproduction apparatus 1 according to the present invention.
It is a plane sectional view of an example. FIG. 2 shows a second embodiment of the bass stereo reproduction apparatus according to the present invention.
It is a plane sectional view of an example. FIG. 3 shows a third embodiment of the bass stereo reproducing apparatus according to the present invention.
It is a plane sectional view of an example. FIG. 4 shows a third embodiment of the bass stereo reproduction apparatus according to the present invention.
It is a figure showing the graph which shows the relationship between a sound pressure relative level and a frequency of Example of FIG. FIG. 5 is a plan sectional view of a conventional bass stereo reproduction apparatus. FIG. 6 is a plan sectional view of a conventional bass reproducing apparatus. In the figure, 41 is a cabinet, 42 and 43 are speakers, 44,
45 is an acoustic filter, 67 is an opening, 71 is a cabinet, 72,
73 indicates a speaker, and 74 and 75 indicate acoustic filters.

Claims (2)

(57) [Claims] 1. A first cabinet to which a speaker for converting a first channel signal into a sound wave is mounted, and a first box is provided so as to communicate with the inside and outside of the first box. A first channel reproduction device including a first acoustic filter having a first cylindrical opening; a second cabinet to which a speaker for converting a second channel signal into sound waves is attached; Box part and the second
A second channel reproduction device including a second acoustic filter having a second cylindrical opening provided to communicate the inside and outside of the box portion, and a second stereo reproduction device comprising: The volume of the first box portion of the first acoustic filter,
The opening area of the cylindrical opening and the length of the first cylindrical opening are respectively the volume of the second box of the second acoustic filter, the opening area of the second cylindrical opening, and The length of the second cylindrical opening is substantially equal to the length of the second cylindrical opening, and the first cabinet of the first channel playback device and the second cabinet of the second channel playback device communicate with each other. , A bass stereo playback device. 2. The bass stereo reproduction apparatus according to claim 1, wherein said first and second cabinets have a phase inversion type structure.