JPS5941359B2 - horn speaker - Google Patents

Description

[Detailed description of the invention] TECHNICAL FIELD This invention relates to horn speakers.

Conventionally, the horn of a horn speaker generally has an internal cross-sectional area change expressed by Sx = So (1+αx)n, and can have various shapes depending on the value of n.

A typical example is shown in Fig. 1, and when n=1, Sx =
So (Hctx), the side wall becomes a parabola as shown by the solid line 1, so it is called a parabolic horn.

When n=2, the conical horn, n
-■, 3 X = 6 rn X, and the dotted line 3
It has a horn shape as shown in , and is called an exponential horn.

These group of horns are called Bessel horns because they are given by Kahessel functions, which are solutions of the intra-horn wave equation.

This Bessel horn was derived from the condition that the horn length is as long as m, but in reality the dimensions are finite, and reflections at the horn opening cannot be ignored, resulting in a level drop in the high frequency range. There is a problem with doing so.

Among these Bessel horns, even in the exponential horn which has the least amount of reflection, the high frequency level decreases as shown in characteristic curve 2 in FIG. 3.

Additionally, this Bessel horn had the disadvantage that its directional characteristics were narrow (and the sound quality changed significantly depending on the listening position).

The present invention aims to reduce the reflection at the horn opening end, which is a drawback of conventional horns such as the Bessel horn, flatten the sound pressure characteristics, and widen the directivity.
Along this line, the horn and driver section ( (not shown).

here, FIG. 2 shows an example of its shape.

Here, the solid line 1 is an example of 5x=eaXb (b>1), and the dotted line 2 is an example of Sx=eaX.

As a result, according to the present invention, the high frequency range is not attenuated as shown by characteristic curve 1 in FIG. 3, and a flat sound pressure characteristic can be obtained, and the directivity is also widened. .

In other words, the horn/speaker of the present invention has a progressively thicker expansion coefficient (axb) than the conventional exponential horn, so impedance matching between the opening and the air is improved, and high frequency efficiency is improved. is improved.

In addition, since the internal cross-sectional area and sidewall function are continuous, reflections within the horn, which operates as an acoustic transmission tube, are reduced, and the radiation impedance seen from the throat of the horn is flattened, reducing the sidelobe level in directivity. You can also do that.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an example of the shape of the horn part of a conventional horn/speaker, Fig. 2 is a diagram showing an example of the shape of the horn part of a horn/speaker according to an embodiment of the present invention, and Fig. 3 is a diagram showing an example of the shape of the horn part of a conventional horn/speaker. This is a characteristic chart showing a comparison of the sound pressure characteristics of the products of the present invention.

Claims (1)

[Scope of Claims] 1. A horn formed by combining a horn with a horn whose internal cross-sectional area change is expressed by the function (1) below, or a horn whose shape change on the side wall of the horn is expressed by the function (2) below, and a driver part.・Speaker. (1) 5x=S□eaxb(b>i)(2)
r=teaX”(b>1) O