JPH0434633Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a speaker cabinet that eliminates the effects of diffraction.

Generally, sound waves emitted from a speaker unit are affected by diffraction depending on the shape of the cabinet. In order to eliminate disturbances in the sound pressure frequency characteristics due to this diffraction, it is desirable that the shape of the cabinet be a smooth curve like a sphere. However, in this case, the buffling effect that pushes the sound pressure to the front is diminished, resulting in a decrease in efficiency. Therefore, from the viewpoint of increasing sensitivity due to the buffling effect, a rectangular parallelepiped cabinet is better. Based on this idea, a cabinet has been devised that incorporates an elliptical curve into the shape of the cabinet.

1 and 2 are schematic diagrams showing examples of such conventional cabinets. FIG. 1A is a side view of the first example, FIG. 1B is a sectional view thereof, FIG. 2A is a side view of the second example, and FIG. 2B is a sectional view thereof. In the first example, the cross section is shaped like an ellipse and is smooth in the lateral direction, but there are corners at the top and the ground plane, and diffraction (indicated by arrows) occurs at these parts.
The second example is a spheroidal cabinet,
In addition to diffraction occurring on the ground plane, the area around the mounting portion of each speaker is irregularly shaped, resulting in a phase difference between the sound waves from each speaker.

In the present invention, in order to improve these drawbacks, the cabinet is made into a superellipsoid. Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 3 is a diagram showing an example of a super ellipse. The hyperellipse is well known, for example, as it was introduced as a new shape in ``Science Asahi'' published in August 1976. An ordinary ellipse is generally expressed by the following formula.

(x/a) ² +(y/b) ² =1 where 2a is the major axis and 2b is the minor axis.

If we extend this ellipse formula and consider the formula (x/a) ⁿ + (y/b) ⁿ = 1, when n = 2, it is an ellipse, but when n>2, the edges of the ellipse swell. beginning, n
At =∞, it becomes a rectangle circumscribing this deformed ellipse (see Figure 3). An ellipse with n>2 that extends slightly outward from a normal ellipse is called a superellipse. That is, a superellipse is located between an ellipse and a rectangle, and has a characteristic that the portion that touches the rectangle has a smaller curve than the ellipse and is almost a straight line. The present invention effectively utilizes the characteristics of this superellipse.

FIG. 4 is a perspective view showing a preferred embodiment of the present invention;
FIG. 5 is a side view thereof. In the figure, 1 indicates a superellipsoidal cabinet as a whole, 1 ₁ is an upper dome, 1 ₂ is a body, and 1 ₃ is a lower dome. 2 is a leg supporting the cabinet 1; 3 is a large-diameter speaker unit; 4 is a medium-diameter speaker unit; and 5 is a small-diameter speaker unit.
The upper dome ₁₁ is a superellipsoidal dome for removing diffraction at the upper part, and the lower dome ₁₃ is a superellipsoidal dome for removing diffraction and reflection at the lower part and the ground plane. These hyperellipsoidal domes are the sixth
As shown in Figures A and B, all cross sections and vertical cross sections based on the apex are constructed so as to partially have hyperelliptic curves. That is, the body 1 ₂ is a cylindrical body having a super elliptical cross section, and the contours or projections of both ends thereof are approximately linear. Furthermore, the cross-sectional view (x-y plane) of the upper and lower domes 1 ₁ and 1 ₃ is shown in Figure 6B.
As _shown in _FIG . The shape is obtained by cutting an elliptical shape along a plane parallel to the x-axis (for example, the x-plane). The super elliptical shape indicated by the dashed-dotted line in FIG. 6A shows a cross section taken along the dashed-dotted line in FIG. 6B. However, the reason why the superelliptic cabinet 1 is divided into an upper dome 1 ₁ , a body 1 ₂ , and a lower dome 1 ₃ is for manufacturing convenience.
These may be constructed as one unit. Therefore, the entire surface of the superelliptic cabinet 1 is continuous and smooth, and there are no parts that cause diffraction. Therefore, it is extremely effective in removing diffraction effects. In addition, since the parts to which each speaker unit 3, 4, and 5 are attached are almost linear when viewed from the side and almost straight when viewed from the vertical (top), the phase difference can be adjusted as shown in the example in Figure 2. It has the advantage of being able to eliminate diffraction effects and utilize the buffling effect at the same time.

FIG. 7 is a curve diagram showing frequency characteristics when the superelliptical cross sections of the upper and lower domes 1 ₁ , 1 ₃ and the body 1 ₂ are set to n=2.7. In the figure, the solid line curve shows the measurement taken with the speaker unit placed in the above-mentioned hyperelliptical cabinet, and the dotted line curve shows the measurement made with the same speaker unit placed in the JIS box. From the figure, it can be seen that the present invention has a remarkable low-frequency effect of peaks and dips.

In the above-described embodiment, superellipsoidal domes are provided at the top and bottom, but the same effect can be obtained even if only the upper dome is provided. Furthermore, it goes without saying that the effect can be obtained even when only a single speaker unit is used or when a buffle hole is provided.

[Brief explanation of the drawing]

FIGS. 1 and 2 are schematic diagrams showing a conventional example, FIG. 3 is a diagram showing an example of a superellipse, FIGS. 4 and 5 are diagrams showing a preferred embodiment of the present invention, and FIG. 6 is a diagram showing the present invention. FIG. 7 is a diagram showing the superellipses of the upper and lower domes of the invention, and is a frequency characteristic curve diagram showing the effects of the invention. 1 ₁ ... Upper hyperellipsoidal dome, 1 ₂ ... Body with superellipsoidal cross section, 1 ₃ ... Lower hyperellipsoidal dome.

Claims (1)

[Claims for Utility Model Registration] 1. A speaker cabinet whose cross section is entirely superelliptical, and at least in the upper part, the longitudinal section with the apex as a reference partially has a superelliptic curve. 2. The speaker cabinet according to claim 1 of the utility model registration, wherein the vertical cross section with respect to the apex also partially has a hyperelliptic curve even in the lower part.