JPS643271Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the cabinet shape of a speaker system.

In conventional rectangular parallelepiped cabinets, the dimensions of the baffle plate to which the speaker unit is attached are finite, so when sound waves pass around it, the propagation direction changes, causing a diffraction phenomenon, which causes peaks and dips in the frequency characteristics. arise. Furthermore, at the front of the cabinet, the shorter the wavelength compared to the dimensions of the cabinet, the greater the influence of diffraction. It is well known that the negative effects of this diffraction can be minimized by making the cabinet spherical; however, spherical cabinets are not easy to manufacture and difficult to install, making them a suitable shape for commercial products for general use. isn't it. Furthermore, since the reflection of the sound wave by the spherical baffle does not occur in one direction like the reflection from the flat baffle, but instead diverges, it has the disadvantage that the frontal sound pressure decreases.

Commonly shaped cabinets that reduce the diffraction of sound waves and eliminate the drawbacks of spherical cabinets include a rectangular cabinet with an arcuate joint surface between the buttful plate and the left and right side walls, as shown in Figure 1. There are some with cut-off corners as shown in Figure 2, but all of them are cylindrical surfaces with a constant radius regardless of the reproduction band of the attached unit, or because there is a ridge at the buffled end. The effect was not complete.

This invention improves the drawbacks of the conventional cabinet in terms of diffraction effects, minimizes the deterioration of the buffling effect, and eliminates the effects of diffraction. Examples thereof will be described below.

In FIG. 3, reference numeral 1 denotes a cabinet, and a tweeter mounting hole 2, a squawker mounting hole 3, and a woofer mounting hole 4 are bored in the bracket 1a in order from the top.

The joint portion between the buttful 1a and the left and right side walls 1b, 1b' has a curvature R that gradually increases upward from the vicinity of the upper part of the bass speaker mounting hole 4, and the curvature R of the joint between the buttful 1a and the left and right side walls 1b, b' Curved surface portions 1d and 1d' in the shape of an inverted cone that smoothly connect with the surface are formed. The radius of curvature R of the curved surface portions 1d and 1d' at the center position of the tweeter mounting hole 2 is 0.3l≦R≦0.6l (1) from the experimental results, where l is the distance from the center of the tweeter to the side wall. It is appropriate to have something.

When the radius of curvature R is smaller than 0.3l, the curved surface part 1
d and 1d' lose their effect as curved surfaces and begin to exhibit the same diffraction effect as the edges. Also, R is 0.6
If it becomes larger, the flat portion of the buffle 1a becomes smaller, resulting in characteristics close to those of a spherical buffle. The radius of curvature R of this corner increases upward, but the dimension of the plane portion of the buff full 1a conversely increases downward. The dimension of this flat portion is one wavelength. Sufficient buff-full effect and diffraction removal effect can be obtained in the high frequency range, which corresponds to the tweeter reproduction band, but in the low frequency range, which corresponds to the long-wavelength band below that frequency, that is, the reproduction band between the squawker and the woofer. Since the surface dimensions are small compared to the wavelength, the effect is similar to that of a spherical baffle, and essentially no diffraction effect occurs.

FIG. 4 shows a modification of the above-mentioned embodiment, in which the boundary between the upper end surface 1e of the baffle 1a and the upper end surface 1e is a cylindrical surface 1f having a radius of curvature R', so that the upper end surface 1a and the baffle 1a are smoothly connected to each other. and the radius of curvature R' is 0.3l'≦R'≦0.6l'. However, l' is from the tweeter to the upper end surface 1e.
This is the distance to. With this structure, Batsuful 1a
The diffraction effect that occurs at the boundary between the upper end surface 1e and the upper end surface 1e is removed, and the characteristics are further improved.

FIG. 5 is a frequency characteristic diagram showing the effect in the tweeter band of the speaker system using the inventive cabinet shown in FIGS. 4a, b, and c, and the speaker system using the conventional cabinet. In the case of the cabinet of the present invention, 51 is 5.
2 is the sound pressure frequency characteristic when a conventional cabinet is used. The dips seen at 2.5KHz and 4.5KHz disappeared by using the cabinet of the present invention, and a sufficient effect was recognized. The cabinet dimensions for this experimental example are 260W x 598H x 250D.

FIG. 6 is another embodiment showing the specific structure of the cabinet of the present invention, and shows an example of the structure of the inverted conical portion. Joint pieces 1g and 1g' having inverted conical surfaces are provided between the baffle 1a and both left and right side surfaces 1b and 1b'. This structure has the advantage of being easy to manufacture.

As mentioned above, this invention has a shape that has an inverted conical surface having a radius of curvature R as shown in equation (1) at the tweeter mounting height position between the butthole of the speaker system and both left and right sides. The present invention relates to a speaker cabinet that is effective in eliminating the adverse effects of cabinet diffraction and obtaining excellent frequency characteristics while having a sufficient baffle area to reflect sound waves forward.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a conventional cabinet, Fig. 2 is a perspective view of another example of the conventional cabinet, Figs. , c are a top view, a front view, and a side view of an example of the cabinet of the present invention, FIG. 5 is a frequency characteristic diagram of the tweeter band when using the conventional cabinet and when using the cabinet of the present invention, and FIG. 6 is the frequency characteristic diagram of the present invention. FIG. 6 is an exploded perspective view showing another embodiment of the invented cabinet. 1...cabinet, 1a...batsful, 1
b, 1b'... left and right side walls, 1d, 1d'... curved surface part,
1e...Top end surface, 1f...Cylindrical surface, 2...Tweeter mounting hole, 3...Squawker mounting hole, 4...Woofer mounting hole.

Claims (1)

[Scope of Claim for Utility Model Registration] In a speaker cabinet in which at least a bass speaker and a treble speaker are to be installed, (1) a portion of the joint between the buttful 1a and the left and right side walls 1b, 1b' has an inverted conical shape; Curved surface portion 1d, 1
Consists of d′. (2) The curved surfaces 1d and 1d' start near the upper position of the bass speaker mounting position. (3) The radius of curvature R of the curved surface portions 1d and 1d' gradually increases upward. A speaker cabinet comprising the above components (1) to (3).