JP2002095074A - Duct for bass reflex type speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a duct for bass reflex type speaker in which bass regeneration characteristics can be regulated easily at a low cost by varying the resonance frequency of the duct. SOLUTION: A part of a member constituting a duct fixed in a speaker cabinet can be fixed removably from the duct such that the duct is opened over the longitudinal direction thereof and the length and the opening area of the duct can be varied simultaneously by varying the dimensions thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bass reflex speaker duct for improving the reproduction characteristics in a low frequency range.

[0002]

2. Description of the Related Art As a speaker system, there is a bass reflex type speaker system having a duct for the purpose of improving reproduction characteristics in a low frequency range. An example is shown in FIG. This is to control the sound pressure in the low frequency range by applying a phase change to the sound coming out of the back of the speaker unit and radiating it from the duct according to Helmholtz's resonance principle, the characteristics of which depend on the resonance frequency of the duct, It is determined by the internal volume of the cabinet and the length of the duct and its open area. In the conventional bass reflex type speaker system, the internal volume of the speaker cabinet, the length of the duct and the opening area thereof are fixed, and the resonance frequency of the duct determined by these is also fixed.

However, the conventional speaker system has a problem that the bass reproduction characteristic is changed depending on the installation environment. Therefore, a bass reflex type speaker system in which the user can adjust the bass reproduction characteristics by changing the resonance frequency of the duct is desired. There was something to change.

[0004]

However, in the prior art, the adjustment work is performed by disassembling the speaker cabinet,
It is very time-consuming, such as requiring assembly,
There were problems such as a complicated structure and a very high cost.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention is directed to a part of a member forming the duct such that the duct installed in the speaker cabinet is opened over its length. Are detachable from inside the duct. By changing the dimensions of the detachable member, the length of the duct and the opening area thereof can be changed at the same time, and the resonance frequency of the duct can be changed easily and at low cost to adjust the bass reproduction characteristics. be able to.

[0006]

Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a perspective view showing one embodiment of the present invention, as viewed from the inside of a speaker cabinet to which it is attached. In FIG. 1, 1 is a speaker cabinet, 2 is a duct body, 3 is a duct component plate and a duct body 2
And a part of a member constituting a duct.

The duct main body 2 is shaped to be open over the length of the duct when the duct constituting plate 3 is removed. The duct main body 2 has attachment portions 2a, 2b, and 2c so that the duct constituting plate 3 can be attached to and detached from the inside of the duct.

The duct forming plate 3 is provided with mounting portions 2a, 2b, 2c.
It is fixed by a screw 4 and a nut 5 which are means for pressing against. The pressing means in this embodiment is provided at a position within reach of a human hand from the opening in the wall surface of the speaker cabinet because of the workability of turning the screw 4. The nut 5 is embedded and fixed in the duct body 2, and the duct constituting plate 3 is provided with a hole 3 a through which the screw 4 is inserted.

FIGS. 2, 3 and 4 show a front view, a side sectional view and a rear view, respectively, of an embodiment of the present invention. FIG. 5 is a side sectional view of the embodiment of the present invention from which the duct component plate 3 is removed, and FIG. 6 is a sectional view taken along line AA of FIG.

The duct constructed as described above is mounted in a speaker cabinet, and functions as a bass reflex speaker duct by forming an opening in the wall of the speaker cabinet.

Since the duct constituting plate 3 can be easily detached from the duct by removing the screw 4, the length of the duct constituting plate 3 functioning as a duct can be changed by changing the dimension L2 of the duct constituting plate 3. Further, by changing the dimension L1 of the duct constituting plate 3, the opening area of the duct can be changed. Therefore, there is no need to disassemble and assemble the speaker cabinet. The duct forming plate 3 is attached to the outer wall surface of the speaker cabinet at one end thereof.

By changing the length of the duct or the opening area of the duct, the resonance frequency of the duct can be changed. However, since the efficiency of the sound radiated from the duct is different, the low frequency sound reproduction is complicated. Both need to be changed to adjust the properties, and the present invention can change them simultaneously.

Further, since the duct constituting plate 3 can be a simple plate-shaped member as in the embodiment, the dimensions L1 and L2 can be changed by preparing the duct constituting plates having different dimensions in advance. It can be implemented easily and at low cost.

Furthermore, although each component of the duct needs to be airtight, the mounting parts 2a, 2b and 2c are on the same plane, and the duct component plate 3 is a plate-like member, so that particularly accurate component precision is required. And airtightness can be maintained by simple pressing means, so that it can be implemented at low cost.

Since there is no step in the duct like the double tube in the prior art, there is no unnecessary diffraction phenomenon of the sound wave, and the function as the duct is stabilized.

The present invention is not limited to the above configuration. For example, the duct main body 2 may be configured by combining simple plate-like members, or a spring or the like may be used as a means for pressing the duct configuration plate 3 against the mounting portions 2a, 2b, 2c.
Further, the opening 6 in the length direction of the duct is not limited to the upper part, but may be formed on the lower part and the side part.

As described above, according to the present embodiment, the bass sound reproduction characteristics can be adjusted easily and at low cost by changing the resonance frequency of the duct.

[0019]

As described above, according to the present invention,
The length of the duct and its opening area can be changed at the same time by changing the dimensions of the simple plate-like member that can be removed from the inside of the duct, making it easy to change the resonance frequency of the duct and adjust the bass reproduction characteristics. it can.

Further, the duct can be manufactured at a low cost because it is constructed without requiring a complicated mechanism or precise component accuracy.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of the present invention.

FIG. 2 is a front view of one embodiment of the present invention.

FIG. 3 is a side sectional view of one embodiment of the present invention.

FIG. 4 is a rear view of one embodiment of the present invention.

FIG. 5 is a side cross-sectional view of the embodiment of the present invention in which the duct constituting plate 3 is removed.

6 is a sectional view taken along line AA of FIG.

FIG. 7 is an overall view of a conventional bass reflex speaker.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 11 Speaker cabinet 2 Duct main body 2a, 2b, 2c Attachment part 3 Duct constituent plate 6 Duct lengthwise opening 17 Speaker unit 18 Duct opening

Claims (2)

[Claims] Claims: 1. A speaker cabinet mounted in a speaker cabinet,
In a duct for a bass reflex type speaker that forms an opening in a wall surface of the speaker cabinet, a part of a member constituting the duct is detachable from the inside of the duct so that the duct is opened over its length direction. Features a duct for bass reflex type speakers. 2. The duct has a mounting portion so that a part of the member constituting the duct can be fixed from inside the duct by a pressing means such as a screw.
The bass reflex speaker duct described.