JPS609295A - Low frequency sound reproducing loudspeaker system - Google Patents

Abstract

PURPOSE:To eliminate effectively a peak of a loudspeaker unit by making a frequency for generating a dip coincide with a high frequency sound resonance frequency of a low frequency sound reproducing loudspeaker unit, in a high band of a gain characteristic of a horn containing an equalizer provided on a throat part of the horn. CONSTITUTION:A low frequency sound reproducing cone type loudspeaker unit 2 provided with a cone paper 3 is attached to a cabinet 1, and a square throat part 5 of a parabolic horn 4 is placed so as to be opposed to the unit 2. A length of one side of the throat part 5 is smaller than the outside diameter of the cone paper 3, and a part of the outside circumferential part of the cone paper is covered with the inside circumferential part of the horn 4. A regular square pyramidal equalizer 6 provided with a spherical opposed part on the bottom part opposed to a central dome part of the cone paper 3 is provided in the center of the throat part 5. As for a size of the horn 4, the equalizer 6, etc., an average path length reaching the throat part 5 from the center part and the outside circumferential part of the cone paper 3 is set so as to become 1/2 of a wavelength of a high frequency sound resonance frequency of the loudspeaker unit 2, and a peak of a sound pressure frequency characteristics can be eliminated effectively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in speaker systems for bass reproduction.

As shown in FIG. 1, the cone-shaped speaker unit for low-pitched sound reproduction has a sound H-frequency characteristic that has a peak at the high-pitched resonance frequency fH.

In order to remove such peaks, conventionally known methods include removing the peaks using a high-cut filter and absorbing the peaks using a sound-absorbing net. However, the effects of both are not sufficient, and the former has a steep high-frequency attenuation characteristic of the high-cut filter (-18-
m-24d B10ct), there is a drawback that the transient characteristics deteriorate.The present invention improves on such conventional drawbacks, and the following is described below.
An embodiment shown in FIGS. 2 and 3 will be described.

In the figure, (1) is a cabinet), (2) is a cone-shaped speaker unit for bass reproduction equipped with cone paper (3), and (4) is a polygon horn with a square throat part (5). The length of the negative side of this throat portion (5) is smaller than the outer diameter of the paper cone (3), and as shown in the figure, a part of the outer periphery of the paper cone (3) is the inner periphery of the horn (4). covered by. (6) is a square pyramidal equalizer with a spherical opposing part at the bottom facing the central dome part (dust cap) of the paper cone (3), and is located at the center of the throat part (5) of the horn (4). Then, the frequency at which a dip occurs in the high range of the gain characteristic of the horn (4) including the equalizer (6) is adjusted to
) to match the number of high-pitched resonance layers fH. That is, the horn (4 ), equalizer (6), etc., as appropriate.

According to the above configuration, the throat portion (5) of the horn (4)
In this case, the phases of the sound waves from the part of the paper cone (3) facing the throat part (5) and the sound waves from the center and outer periphery of the paper cone (3) are opposite at the high-pitched resonance frequency fH of the speaker unit (2). Because the rain sound waves cancel each other out, the gain characteristics of the horn (4) including the equalizer (6) have a large difference at the high-pitched resonance frequency fH of the speaker unit (2), as shown in Figure 4. It causes a drop. Therefore, the sound pressure frequency characteristics of the speaker system are a combination of the gain characteristics of the horn (4) including the equalizer (6) and the sound pressure frequency characteristics of the speaker unit (2). As shown in 0, the peak at the high-pitched resonance frequency fH is removed.
In the figure, d indicates the characteristics of a speaker system that does not include a horn and an equalizer.

In short, the present invention converts the frequency at which a dip occurs in the high range of the gain characteristic of the horn (4) including the equalizer (6) to the high-pitched resonance frequency fH of the speaker unit (2).
Since this speaker unit is designed to cancel and remove the peak at the high-pitched resonance frequency fH of 1-(2), the format and shape of the horn and equalizer are limited to those of the above embodiment. However, it can also be realized by various types and shapes, such as an exponential horn, a conical equalizer, etc.

As described above, the present invention provides the throat portion (
5), an equalizer (6) is arranged in the throat section (5), and the gain characteristics of the horn (4) including the equalizer (6) are adjusted. Since the frequency that causes the dip in the high range is made to match the high-pitched resonance frequency fH of the speaker unit (2), this speaker unit (2)
This has the advantage that the peak at the high-pitched resonance frequency fs can be effectively removed.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the sound pressure frequency characteristics of a speaker unit, FIGS. 2 and 3 are diagrams showing the structure of the bass reproduction speaker system of the present invention, and FIG. 4 is a diagram showing the sound pressure frequency characteristics of the speaker unit. . (2) u speaker unit, (4) is horn, (5)
is the throat part, and (6) is the equalizer.

Claims (1)

[Claims] In a structure in which a speaker unit for bass reproduction (2) is arranged opposite the throat part (5) of the horn (4),
A K equalizer (6) is arranged in the throat section (5), and the frequency that causes a dip in the high range of the gain characteristic of the horn (4) including the equalizer (6) is adjusted to the high-pitched resonance frequency fH of the speaker unit (2). A speaker system for bass reproduction characterized by matching.