JPH0638547Y2 - Speaker-cabinet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a speaker cabinet.

[Prior Art] Conventionally, a method has been put to practical use in which a reinforcing bar or a reinforcing bar is attached to a cabinet to increase the mechanical strength of the box itself and to disperse and damp the vibrations of the baffle plate, the side plate, and the back plate. However, among them, there is, for example, Japanese Utility Model Application Laid-Open No. 58-147376 for the purpose of damping the plate vibration of the baffle plate.

The one described in the publication has a structure in which a narrow groove in the plate thickness direction is provided around a speaker unit of a baffle plate, and this groove is filled with a viscoelastic material such as rubber.

[Problems to be solved by the invention] One of the factors causing the plate vibration of the baffle plate is the reaction of the speaker unit. However, since the conventional structure has a groove in the baffle plate, the mechanical strength of the baffle plate is low. Get smaller. Therefore, the baffle plate as the reference of the sound source (speaker unit) vibrates and easily emits sound, so that the sound from the speaker unit is superimposed on the sound from the speaker unit and the response characteristic of the system is However, there is a problem in that it deteriorates the transient characteristics and distortion characteristics.

The inventors have proposed, for example, the following structure in order to solve such a problem. (Actual application
60-001967) Referring to FIG. 5, at the joint between the baffle plate (1) and the side plate (2) of the cabinet, the plate surface of the baffle plate (1) is almost extended over the entire circumference of the side plate (2). This structure has parallel slit-shaped grooves (4).

In such an improved structure, the vibration propagating from the speaker unit (5) through the baffle plate (1) to the side plate (2) and the back plate (3) has a slit-like groove (4) part (vibration That is, by changing the cross-sectional area of the medium, the characteristic impedance of that portion is changed), and the vibration of the side plate (2) and the back plate (3) is reduced.

However, such an improved structure is a structure in which a slit-like groove is provided over the entire circumference of the side plate of the cabinet, so that the mechanical strength of the cabinet is reduced, notwithstanding the effect of reducing plate vibration. There was room for improvement.

The first object of the present invention is to solve such a problem. The second purpose is to suppress the generation of standing waves in the cabinet.

[Means for Solving Problems] The present invention is a speaker cabinet composed of a baffle plate, a top plate, left and right side plates, a bottom plate and a back plate, and has a U-shaped periphery except for a portion joined to the bottom plate of the baffle plate. A slit-like groove is provided, and the first end face portions of the first and second reinforcing plates are attached to the portions of the baffle plate facing the left and right side plates through the slit-like groove, and the first and second reinforcements are attached. The second end surface portion of the plate is attached to the bottom plate, respectively, and a plurality of acoustic plates are provided between the third inclined end surface portions of the first and second reinforcing plates at an arbitrary angle and at a predetermined interval. It is characterized in that they are arranged separately.

[Operation] As a result, the baffle plate and the bottom plate are firmly fixed by the first and second reinforcing plates, the mechanical strength of the cabinet as a whole is increased, and the baffle plate is removed from the speaker unit as the vibration source. Vibrations passing through to the top plate and the left and right side plates are damped by the U-shaped slit-shaped groove provided in the baffle plate. That is, the characteristic impedance of the portion is changed by changing the cross-sectional area of the medium, and the vibration damping effect when the vibration propagates to the medium having the different characteristic impedance is effectively used.

Further, the vibration energy propagating from the lower part of the baffle plate to the bottom plate is absorbed by the floor or the table on which the speaker cabinet is mounted.

In addition, between the parallel and opposite plate surfaces of the speaker cabinet (for example, top plate and bottom plate, left side plate and right side plate).
Since the effective lengths of the one plate surface and the acoustic plate are different at the position or place on the plate surface, the standing wave is dispersed and the occurrence of a significant standing wave is prevented. Such a standing wave dispersion action is large in the low frequency band in which the half-wavelength is longer than the distance between the plate bodies, and has an action of scattering the standing wave by scattering the sound wave in the high frequency band.

[Embodiment] A first embodiment will be described with reference to FIGS. 1 and 2.

Around the periphery of the baffle plate (1) excluding the portion joined to the bottom plate (8), that is, the top plate (6), left and right side plates (7a), (7b)
A slit-shaped groove (9) having a narrow shape in the plate thickness direction and having a U-shape as a whole is provided at the joint portion with. Then, the left and right side plates (7a), (7) are inserted through the slit-shaped grooves (9) of the baffle plate (1).
The first vertical end faces of the right and left triangular reinforcing plates (10) and (11) are attached to the portions facing b), respectively, and the first and second reinforcing plates (10) are attached. , (11) are attached to the bottom plate (8), respectively. And, a plurality of acoustic plates not necessarily having a constant width and a constant shape between the third inclined end surface portions (10a) and (11a) of the first and second reinforcing plates (10) and (11). (12), (12), ...
Install with fixed or indefinite intervals.
In this case, both ends of the acoustic plates (12), (12), ... Do not touch or abut the left and right side plates (7a), (7b).

The shape of each acoustic plate (12), (12), ... is not limited to a rectangle, but may be a trapezoid, a mountain, or the like.

Next, in this embodiment, the size (unit: mm) of each part of the cabinet is determined as shown in FIG. 4, and the outer diameter is 280 W × 466 H × 232 D t = 12, 11 = 1, 12 = 3 Baffle plate (1) Attach a shaker (13) with the same structure as the speaker unit in the center of the unit, and apply an impulse vibration by this shaker (13) to each part P1: Frame of the shaker P2: Near the frame P3: Side plate Center P4: The plate vibration response waveform at the center of the side plate was measured.

FIG. 6 shows the measurement results of this embodiment, FIG. 7 shows the improved structure (with slit-shaped grooves), and FIG. 8 shows the measurement results of the conventional example (without slit-shaped grooves).

In addition, the sound pressure frequency characteristics of the speaker system using the speaker cabinet with the size of the sound plate set to 250 × 30 × 9 mm, the 12 sound plates arranged at 15 mm intervals, and their mounting angles set to 65 degrees. It was measured. The measurement results are shown in FIG.
The solid line is the present example, and the broken line is the conventional example (no slit groove, no acoustic plate). In this example, it is confirmed that peaks and dips disappear in the band of 400 to 2000 Hz.

FIG. 3 shows another embodiment, in which the first and second reinforcing plates (1
0) and (11) are integrally provided with stepped step portions (14), (14), ... On the third inclined end surface portions (10a) and (11a), and these stepped step portions (14) and (14), 14), ... on the horizontal part of the acoustic plate (12),
(12), ... is a structure with attached.

[Advantages of the Invention] The present invention has the following advantages: (a) The baffle plate and the bottom plate are firmly fixed by the first and second reinforcing plates, so that the mechanical strength of the cabinet as a whole is increased, and (b) the vibration. From the speaker unit as a source, through the baffle plate, the top plate,
The vibration propagating to the left and right side plates is damped by the U-shaped slit-shaped groove of the baffle plate. (C) Further, the vibration energy propagating from the lower part of the baffle plate to the bottom plate is absorbed by the floor or the table on which the speaker cabinet is mounted.
(D) As a result, the plate vibrations of the left and right side plates and the back plate of the cabinet are significantly reduced, and the deterioration of various characteristics due to the plate vibration is improved. (E) Further, by dispersing and scattering the standing wave in the cabinet, it is possible to suppress the generation of the standing wave.

[Brief description of drawings]

1 and 2 are views showing the structure of a speaker cabinet (one embodiment) of the present invention, FIG. 3 is a view showing the structure of the other embodiment, and FIG. Fig. 5 is a diagram showing the dimensions of Fig. 5, Fig. 5 is a diagram showing the structure of the improved speaker cabinet, and Fig. 6 is a vibration response waveform diagram of each part to the impulse of the speaker cabinet (one embodiment) of the present invention. , FIG. 7 is a vibration response waveform diagram of each part for impulse of an improved speaker cabinet, FIG. 8 is a vibration response waveform diagram of each part for impulse of a conventional speaker cabinet, and FIG. 9 is a speaker of the present invention. It is a sound pressure frequency characteristic figure of a cabinet (one example). (1) …… Baffle board, (3) …… Back board, (5) …… Speaker unit, (6) …… Top board, (7a), (7b)…
... Left and right side plates, (8) ... bottom plate, (9) ... slit grooves, (10), (11) ... first and second reinforcing plates, (12) ...
… Acoustic plate.

Claims (3)

[Scope of utility model registration request] 1. A soaker cabinet comprising a baffle plate (1), a top plate (6), left and right side plates (7a), (7b), a bottom plate (8) and a back plate (3). )
A U-shaped slit-shaped groove (9) is provided around the back surface of the baffle plate (1) except for a portion to be joined with the bottom plate (8). The first end faces of the substantially triangular first and second reinforcing plates (10) and (11) are attached to the portions facing the left and right plates (7a) and (7b), respectively, and the first and second The second end faces of the two reinforcing plates (10) and (11) are attached to the bottom plate (8), respectively, and the first and second reinforcing plates (1
A plurality of acoustic plates (1) are provided between the third end face portions of (0) and (11).
Speaker cabinets characterized in that 2), (12), etc. are arranged at an arbitrary angle and at predetermined intervals. 2. The first and second reinforcing plates (10), (11) are right-angled triangles, respectively, and the end face portions orthogonal to each other are the first and second end face portions, and the third end face. Claims for utility model registration, characterized in that rectangular acoustic plates (12), (12) ... Are arranged at predetermined intervals between the parts.
Speaker cabinet described in paragraph. 3. The stair-like step portions (14), (14) ... Are integrally provided on the third end face portions of the first and second reinforcing plates (10), (11), respectively, and the step-like step portions are formed. Speaker cabinet according to claim 2, characterized in that acoustic plates (12), (12) are attached to the horizontal portions of the steps (14), (14), respectively. Net.