JPS5912232B2 - Indoor sound equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an indoor acoustic device that radiates sound waves in two contradictory directions from one speaker. Regarding things that can be used effectively.

In a radial speaker, sound waves are radiated to the front and back sides as the cone vibrates, but the phase difference between them is 180 degrees, so if both sound waves interfere near the speaker,
The sound waves cancel each other out, reducing the sound pressure and deteriorating the sound quality.

Therefore, a baffle plate is used to block the sound waves emitted from the front and back sides, but the size of this baffle plate is limited due to practical design considerations, and interference between the two types of sound waves is unavoidable.

In particular, low-frequency sound waves with poor directivity tend to cause interference between the sound waves radiated to the front and back surfaces, and therefore
When attempting to utilize sound waves generated at the front and rear sides of two speakers, the sound pressure of the reproduced sound in the bass range, which is particularly important for stereo sound effects, decreases, so improvements in this point are desired.

The present invention was made in view of these points, and includes providing a speaker with a baffle plate and horns on the front and back sides of the speaker to give each sound wave contradictory directivity. , while effectively utilizing the sound waves generated on both sides of the speaker, the drop in sound pressure in the bass range is reduced.

Next, an embodiment of the present invention will be described with reference to the drawings.

Reference numeral 1 denotes an enclosure. The enclosure 1 is formed of a wooden board into a rectangular shape measuring 80 CrrL in length and 58 CrrL in width. The front and back sides are open, and a Saran net 3 is stretched over each opening 22.

Further, 4 is a speaker with an outer diameter of 28 crfL, and this speaker 4 has a cone 6 inside a conical frame 5, and an acoustic vibration mechanism 7 is attached to this cone 6. A collar portion 8 is provided protrudingly.

Upper, lower, left, and right side plates 1a are located at the center connecting the front and rear ends of the enclosure 1 in the left-right direction.

1b, 1c, and 1d, a wooden baffle plate 9 is provided in close contact with the baffle plate 9, an opening 10 is provided near the center of the baffle plate 9, and the collar portion 8 of the speaker 4 is attached to the opening 10. and the back faces of the saran nets 3, 3, respectively.

Furthermore, a pair of exponential holes 711.degree. 11 are symmetrically provided on the front and back surfaces of the baffle plate 9, respectively, from the periphery of the speaker 4 to the front and back.

A pair of these horns 11.11 are provided symmetrically.

This horn 11.11 is made of a material that is difficult to resonate in the audible frequency range, such as concrete with a thickness of 12 mrn,
The periphery of the opening 12 at the base end is formed thick, and wood is attached to both sides of the periphery of the opening 10 of the baffle plate 9, so that the front and back surfaces of the speaker 4 are seen forward and backward, respectively, and the tip Vertical flanges 11a are protruded from the periphery, and the outer peripheral end surfaces of these flanges 11a are the upper, lower, left, and right side plates 1a, 1 of the enclosure 1, respectively.
b, 1c, and 1d, and this collar edge 11
The surface of a facing the Saran net 3 is located inwardly at a slight distance from the Saran net 3, forming a so-called free edge.

Note that if the distance between the upper and lower ends of the horn 11 is larger in the upper part and smaller in the lower part, the quality of the bass sound will be better.

Further, 14 is a portable cabinet attached to the outside of the bottom of the enclosure 1.

In such a configuration, when the speaker 4 is operated indoors to generate sound, the sound waves are radiated to the front and rear sides, and are guided by the respective horns 11 and 11 to the Saran net through the opening 2° 2 of the enclosure 1. 3,3
is propagated into the air via

At this time, each sound wave (especially sound waves in the low frequency range with poor directionality) is given directionality by the horns 11, 11, so the front and back sound waves do not interfere near the speaker 4, and the horn 11. According to 11, one of the directional sound waves, for example, the sound waves on the front side, is directly captured by the sound receiving point, while the other sound waves, for example, on the back side, are reflected from the walls of the room and captured at the sound receiving point, and rain sound waves. The overlapping point is a far point away from the speaker 4 and the transmission distance is also different, so you can listen to faithful reproduced sound without lowering the sound pressure level and reducing the drop in sound pressure in the low frequency range, which is particularly problematic.

Note that there is no problem because the sound waves that have gone around the tip edge of the horn IL11 (7) due to the diffraction phenomenon are blocked by the baffle plate 9.

In this way, the speaker 4 is considered to have speakers 4a and 4b on the front and back sides, and each speaker 4a and 4b emits sound waves in two opposite directions independently of each other, one as direct sound and the other as direct sound. Since the sound can be received as reflected sound from the walls of the room, even if it is used in a small room, it can provide the realistic feeling of receiving live sound in a large hall with excellent acoustics.

At this time, since the horns 11 and 11 are made of concrete, they cause resonance by sound waves in the audible frequency range of audio, which prevents unpleasant sounds from occurring.
Negative effects on the mechanical properties of the structure can also be prevented.

Further, the flange edge 1'1a at the tip of the horn 11.11 is the top, bottom, left and right side plates 1a, 1b of the enclosure 1.

1c, 1d, and the upper, lower, left, and right side plates 1a, 1b are spaced apart from the Saran net 3, so the sound from the speaker 4 is generated through the baffle plate 9.

Since the vibrations of the horns 1c, 1d and the Saran net 3 are not directly received, and the vibrations at the tips of the horns 11 and 11 are not transmitted to each other via the enclosure 1, the occurrence of so-called chatter can be avoided.

Note that the horn 11 may have not only an exponential shape but also a conical shape or a pyramid shape.

Furthermore, the material that does not resonate is not limited to concrete, but may also be a similar material such as ceramic.

According to the present invention, the speaker is provided with a baffle plate and horns are provided on the front and back sides of the speaker to give each sound wave opposite directivity, so that the phase of each sound wave, that is, the compression wave, is Even if they differ by 180 degrees, they will not interfere with each other, including the bass range.

Therefore, it is treated as if the reproduced sound were generated from two speakers using one speaker, and the sound waves generated on the front and back surfaces of the speaker can be effectively utilized.

One of the sound waves directionally emitted from the front and rear sides of the speaker by the respective horns is directly captured by the sound receiving point, while the other is captured as reflected sound from the walls of the room. Even when used indoors, it can provide the realistic feeling of receiving live sound in a large hall with excellent acoustics.

In addition, since the periphery of the tip of the horn is separated from the enclosure wall, the vibrations of the speaker transmitted to the enclosure and the vibrations of the tips of each horn are not transmitted to each other (the occurrence of chatter can be prevented).

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an exposed speaker of an embodiment of the device of the present invention, FIG. 2 is an enlarged front view thereof, and FIG. 3 is a longitudinal sectional side view thereof. 1...Enclosure, 4...Speaker, 9...
・Baffle plate, 11...horn.

Claims (1)

[Claims] 1 In an enclosure with the front and back closed,
A baffle plate is provided whose periphery is in close contact with the inside of the enclosure, a speaker is attached to this baffle plate, and horns are provided on the front and rear sides of the speaker to independently direct the sound waves generated in each to the front side and the rear side. , an indoor acoustic device characterized in that the tip periphery of each horn is spaced apart from the inside of the enclosure.