JPS6120491A - Speaker device - Google Patents

Abstract

PURPOSE:To eliminate the irradiation of only a harmful frequcncy by providing a hole-type frequency band cut-off resonance mufler provided with a holed cylinder, which has a diameter smaller than that of a buss reflector-type low frequency reinfocing duct and forms an annular space between said duct and its innte peripheral surface, on some part of the inner peripheral surface of said duct. CONSTITUTION:A cylindrical holed-type frequency band cut-off resonance mufler 9 fitted on the enitire inner peripheral surface of a buss reflectro-type duct 7 is constituted of a holed cylinder 11, whicg has a diameter smaller than that of said duct 7 and forms an annular space 10 between said duct 7 and its inner peripheral surface, and a fitting flange board 12 provided on both outer peripheral edges of said cylinder 11. The resonance mufler 9 is produced by, for instance, metal or molded resin. A circular or rectangular foled part 14 for extending the circular space 10 at certain foling depth is formed on each hole 13 of the cylinder with holes 11. With such constitution, the resonance mufler 9 provided on the buss reflector-type duct 7 can attenuate the irradiation of a hurmful wave, and the disturbance of a sound pressure frequency characteristic and directivity characteristic can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to improving the sound quality of a high-fidelity reproduction speaker device for consumer or business use.

Conventional configurations and their problems In general, a bass reflex system is widely used as a method for enhancing the bass range of high-fidelity reproduction speaker devices. An outline of this method will be explained based on FIGS. 1 and 2.

In the figure, (1) is a speaker cabinet, (2) (
3) is a treble speaker unit and a bass speaker unit installed on the front of the speaker cabinet (1).
(4) is a bass reflex type bass reinforcement duct (hereinafter referred to as "bass reflex duct") located below the bass speaker unit (3) and provided on the front of the speaker cabinet (1), and (5) is the speaker cabinet (1). ) is a band division crossover network circuit provided in Note that (6) indicates openings at both ends of the bass reflex duct (4).

This method is based on the opening (6) of the bass reflex duct (4), the volume of the speaker cabinet (1), and the volume of the bass reflex duct (4).
) The resonant frequency fD obtained by the mass of air in
is used to enhance and radiate bass sounds, and fo is usually adjusted to a low frequency of 507 to 1oOHz. At frequencies above fD, the radiation of sound waves from the bass reflex duct (4) is ignored, but the high frequency new station frequency of the bass speaker unit (3) determined by the network circuit (5) is determined by the network circuit (5). If the frequency is higher than the frequency where the distance between the rear surface of the speaker unit (3) and the opening (6) of the bass reflex duct (4) is one wavelength, or this speaker system does not have a band division circuit using a full-range speaker unit. In the case of a full-range bass reflex speaker device, the sound waves emitted from the rear surface of the bass speaker unit (3) reach the opening (6) of the bass reflex duct (4) at exactly one wavelength (in phase), and the bass speaker unit (3) Since the sound wave is emitted in the opposite phase to the sound wave emitted from the front surface, at this frequency, a positive and negative dual sound source exists on the speaker baffle surface, and the sound pressure frequency characteristics and directional characteristics of the speaker device etc. It is known that this can cause significant disturbances. This frequency is around 30an in an ordinary home high-fidelity reproduction speaker device, where the distance between the liquid level of the bass speaker unit (3) and the opening (6) of the bass reflex duct (4) is long. From the relationship with the speed of the sound wave in the air, 340 m/s, it becomes approximately I K t(z).

Therefore, this harmful component actually poses a problem in speaker devices and full-range speaker systems in which a frequency of approximately IKl is radiated from a bass speaker unit. For this reason, conventionally, when determining the assigned frequency band of the bass speaker unit (3) of the speaker device, there was a problem in that there was a limit to the distance between the bass speaker unit (3) and the bass reflex duct (4).

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional problems, and aims to provide a speaker device that can remove only harmful frequency radiation with a simple configuration.

Structure of the Invention In order to achieve the above object, the speaker device of the present invention is a bass reflex speaker device having a speaker cabinet, a speaker unit, and a bass reflex bass enhancing duct, wherein the speaker device includes a speaker cabinet, a speaker unit and a bass reflex bass enhancing duct. A perforated band having a perforated cylindrical body on a part or the entire circumferential surface thereof, which has a diameter smaller than that of the bass reflex bass reinforcement duct and forms an annular space between it and the inner peripheral surface of the bass reflex bass reinforcement duct. It has a configuration in which a cut-off resonance muffler is attached, and thereby, the harmful sound waves emitted from the bass reflex bass reinforcement duct can be easily absorbed by the perforated band cut-off resonance muffler, which has a simple configuration. The distance between the bass speaker unit and the bass reflex duct can be set freely.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. Note that the configuration of the parts other than those shown in the drawings is the same as that shown in FIG.

In the figure, (7) is a cylindrical (or rectangular) bass reflex duct made using a paper or resin molding machine, and (8) is an opening at both ends thereof.

(9) A perforated band-cutting resonance muffler (hereinafter referred to as "resonance muffler") in the form of a circular tube (or square tube) attached to the entire inner peripheral surface of the bass reflex duct (7). A perforated cylindrical body (11) having a smaller diameter and forming an annular space lO between the inner circumferential surface of the bass reflex duct (7), and mounting holes provided on both outer peripheral edges of this perforated cylindrical body (11). It is composed of a flange plate (12). This resonance muffler (9) is manufactured using, for example, a metal or resin molded product. Each hole 13) of the perforated cylinder (]]) is formed with a circular or rectangular folded portion (14) extending into the annular space (10) with a constant folding depth. Note that the single resonant muffler (9) is considered to be a band-cut filter equipped with a large number of Helmholtz resonators, similar to a normal muffler.
Band of harmful sound waves that is currently attracting attention (approximately 1.kl[z)
Considering this, it is clear that it can be constructed with realistic dimensions.

According to this configuration, the radiation of harmful sound waves is attenuated by the resonance muffler (9) attached to the bass reflex duct (7), and disturbances in sound pressure frequency characteristics and directivity characteristics are reduced.

In addition, in this embodiment, the number hole (1) of the perforated cylinder (11) is
3) is adjusted to a specific frequency by keeping the size and shape constant, but by appropriately changing the thickness and shape of the hole (13), the band 11 and Q of the cutoff band can be changed. , it is possible to easily deal with disturbances in characteristics.

In this example, a resonance muffler (9) is attached to the entire inner circumferential surface of the bass reflex duct (7), but a small resonance muffler (9) is attached to a part of the inner circumferential surface of the bass reflex duct (7). A similar effect can be obtained by installing a silencer (9).

Effects of the Invention According to the present invention, harmful sound waves emitted from a bass reflex type bass reinforcement duct can be easily absorbed by a perforated band-cutting resonance muffler with a simple configuration, and a bass reflex speaker unit and a bass reflex The distance between the ducts can be set freely.

Therefore, it is extremely advantageous in designing the characteristics of the speaker device.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional bass reflex speaker device, FIG. 2 is an enlarged sectional view of the same essential parts, and FIG. 3 is an enlarged sectional view of the essential parts of a bass reflex speaker device according to the present invention.

Claims (1)

[Claims] 1. A bass reflex speaker device having a speaker cabinet, a speaker unit, and a bass reflex bass reinforcement duct, wherein the bass reflex bass reinforcement duct is provided with a bass reflex bass reinforcement duct on a part or the entire inner peripheral surface of the bass reflex bass reinforcement duct. A speaker device equipped with a perforated band-cutting resonance muffler having a perforated cylindrical body having a diameter smaller than that of a duct and forming an annular space between it and the inner peripheral surface of the bass-reflex type bass-reinforcing duct.