JPH04235500A - Bass-reflex type speaker system - Google Patents

Abstract

PURPOSE:To efficiently utilize the entire baffle surface by sharing sound emitting space between sound emission from a speaker unit and that from an acoustic port. CONSTITUTION:By providing a plurality of opening parts 8 and 9 at a part of an acoustic horn 12 located on the front of a speaker unit 1 so that the horn is open toward a baffle surface 10, attaching sound absorption material 13 and 14 covering the geometric shape of the horn within the opening parts 8 and 9, and using the opening parts 8 and 9 also for the opening parts for sound ports 2 and 3, the internal space of the horn 12 can be shared between the sound emission from the speaker unit 1 and that from the acoustic ports 2 and 3.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-pipe duct type bass reflex speaker system in which the area of a baffle surface can be efficiently utilized for sound radiation.

0002

[Prior Art] Conventionally, a multi-pipe duct type bass reflex speaker system has been known in which a flat characteristic is obtained by dispersing the resonance of the acoustic port by providing acoustic ports of different lengths. ing.

FIG. 6 shows, for example, "Speaker System (Bottom)" (written by Takeo Yamamoto, Radio Gijutsusha, July 15, 1970).
First edition) P. 284 (FIG. 8.40) is a sectional view of a conventional multi-pipe duct type bass reflex speaker system, and FIG. 7 is a front view of the same. In the figure, 1 is a speaker unit that radiates sound to the outside, 2 is a first acoustic port that radiates low-frequency sound, and has an opening 8 in the front surface thereof. 3 is a second acoustic port having a different length from the first acoustic port 2.
, which has an opening 9 on its front side. 4 is the sound radiated from the front side of the speaker unit 1, 5 is the sound radiated from the back side of the speaker unit 1, 6 is the sound radiated from the first acoustic port 2, and 7 is the second acoustic port. Sound is radiated from 3, 10 is a baffle surface of the speaker unit 1, and 11 is a cabinet that accommodates the speaker unit 1, the first acoustic port 2, the second acoustic port 3, and the like.

[0004] Next, the operation of the above configuration will be explained. The sound 5 emitted from the back side of the speaker unit 1 has a low frequency sound enhanced by passing through the first acoustic port 2 and the second acoustic port 3, and the sound 5 emitted from the front side of the speaker unit 1 is intensified. is synthesized with Therefore, the bass range is expanded by the amount of sound radiated from the acoustic ports 2 and 3.

[0005] Furthermore, the bass reproduction limit frequency fob of the speaker unit 1 housed in the bass reflex type cabinet 11 is
If the equivalent stiffness of the cabinet 11 is sc, and the sum of the equivalent masses of the acoustic ports 2 and 3 is mι, then

00
06]

[Math 1]

As shown in FIG. 6, the first
If the area of the opening 8 of the acoustic port 2 and the opening 9 of the second acoustic port 3 are equal, if the length of each acoustic port 2, 3 is adjusted so that mι set at the time of design does not change,
The resonance of ports 2 and 3 is dispersed, and there is no disturbance in the output sound pressure frequency characteristics.

[0008]

[Problems to be Solved by the Invention] Since the conventional multi-pipe duct type bass reflex speaker system is configured as described above, as shown in FIG.
When disposing on the baffle surface 10, the baffle surface 10
It was necessary to form the openings 8 and 9 of the plurality of acoustic ports 2 and 3, and it was necessary to secure a larger area of the baffle surface 10 accordingly.

[0009] This invention was made to solve the above-mentioned problems, and the sound radiation space from the speaker unit and the sound radiation from the acoustic port are shared, so that the entire baffle surface is covered. The purpose of the present invention is to provide a multi-pipe duct type bass reflex speaker system that can be used efficiently.

0010

[Means for Solving the Problems] A bass reflex type speaker system according to the present invention includes an acoustic horn that opens toward the baffle surface on the front surface of a speaker unit, and a plurality of openings in a part of the acoustic horn. By placing a sound absorbing material along the shape of the horn inside this opening and also using the opening as the opening of the acoustic port, the sound radiation from the speaker unit and the sound radiation from the acoustic port can be absorbed into the horn. It is characterized by being configured so that the internal space is shared.

[0011]

[Operation] According to the present invention, an acoustic horn is arranged in front of the speaker unit built into the cabinet, and a part of the acoustic horn is used as an opening of the acoustic port, so that the sound emission space from the speaker unit and the acoustic port are separated from each other. By sharing the sound emission space with the baffle surface, it becomes possible to use the baffle surface efficiently.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a multi-pipe duct type bass reflex speaker system according to an embodiment of the present invention, and FIG. 2 is a front view of the same. In a considerable part,
The same reference numerals are used to omit their explanation.

In FIGS. 1 and 2, reference numeral 12 directs the sound 4 emitted from the front surface of the speaker unit 1 to the baffle surface 10.
acoustic horns 13 and 14 lead to the first acoustic port 2;
This is a sound absorbing material arranged along the horn shape in the opening 8 of the second acoustic port 3 and the opening 9 of the second acoustic port 3, respectively.

Next, the operation of the above configuration will be explained. As shown in FIG. 1, an acoustic horn 12 is arranged in front of the speaker unit 1 to guide the sound 4 emitted from the front surface of the speaker unit 1 to the baffle surface 10, and the sound 4 is emitted from the first acoustic port 2. The sound 6 and the sound 7 radiated from the second acoustic port 3 are transmitted through openings 8 and 9, respectively.
A portion of the acoustic horn 12 is used as the openings 8 and 9 of the acoustic ports 2 and 3.

That is, in a part of the acoustic horn 12,
Since the opening 8 of the first acoustic port 2 and the opening 9 of the second acoustic port 3 are provided, the two acoustic ports 2 and 3 of different lengths disperse the resonance of the ports, so that the flat The output sound pressure frequency characteristics can be obtained.

Further, sound absorbing materials 13 and 14 are disposed in the openings 8 and 9, respectively, along the shape of the horn, and these sound absorbing materials 13 and 14 keep the horn shape at a constant spread and at the same time, Demonstrates the effect of absorbing sound in the range. Therefore, the disturbance of the sound radiated from the front surface of the speaker unit 1 via the acoustic horn 12 is reduced, and the sound radiated from the first acoustic port 2 and the second acoustic port 3 and the sound from the speaker unit 1 are reduced. Since the sound radiation space can be shared with the radiator, there is no need to secure an area for the acoustic port on the baffle surface 10, and the baffle surface 10 can be used efficiently.

FIG. 3 is a frequency characteristic diagram of the multi-pipe duct type bass reflex type speaker system according to the present invention, in which the solid line A indicates the characteristics of the speaker system of the present invention, and the dashed line B indicates the characteristics of the two Acoustic port 2, 3
The characteristics are shown when the equivalent mass mι of is the same. As is clear from FIG. 3, the speaker system according to the present invention provides flat characteristics in the high frequency range.

In the above embodiment, the areas of the opening 8 of the first acoustic port 2 and the opening 9 of the second acoustic port 3 are made equal, and the areas of the opening 8 of the first acoustic port 2 and the opening 9 of the second acoustic port 3 are By changing the length of the acoustic ports 2 and 3, the resonant frequencies of the individual ports 2 and 3 were dispersed.However, as shown in FIGS. 4 and 5, changing the length and area of the acoustic ports 2 and 3 can It has the same effect as the example.

[0019]

As described above, according to the present invention, a plurality of openings are provided in a part of the acoustic horn disposed with the baffle surface open in front of the speaker unit built into the cabinet, and these openings are Since the baffle is configured to serve as the opening for multiple acoustic ports of different lengths, the entire baffle surface can be used efficiently for sound radiation.
Flat frequency characteristics can be obtained without increasing the area of the baffle surface.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a multi-pipe duct type bass reflex speaker system according to an embodiment of the present invention.

FIG. 2 is a front view of FIG. 1.

[Fig. 3] Output sound pressure of the speaker system according to the present invention/
It is a frequency characteristic diagram.

FIG. 4 is a sectional view of a bass reflex speaker system according to another embodiment of the invention.

FIG. 5 is a front view of FIG. 4;

FIG. 6 is a sectional view showing a conventional bass reflex speaker system.

FIG. 7 is a front view of FIG. 6;

[Explanation of symbols]

1 Speaker unit 2 First acoustic port 3 Second acoustic port 8,9 Opening 10 Baffle surface 11 Cabinet 12 Acoustic horn 13,14 Sound absorbing material

Claims (1)

[Claims] Claim 1: In a multi-pipe duct type bass reflex speaker system in which a speaker unit that radiates sound to the outside and a plurality of acoustic ports that radiate low-frequency sound are arranged in a cabinet, a front surface of the speaker unit is provided. An acoustic horn that opens toward the baffle surface is installed on the
A plurality of openings are provided in a part of this acoustic horn, and a sound absorbing material is placed along the shape of the horn within these openings, and
A bass reflex device characterized in that the opening is shared with the opening of the acoustic port, so that sound emission from the speaker unit and sound emission from the acoustic port are performed by sharing the space inside the horn. type speaker system.