JPH10341493A - Wide directional characteristic loud speaker device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flat wide directional characteristic over the whole periphery of a device by arranging plural speakers on the peripheral part of a polygonal or spherical loud speaker device main body, setting an angle which the axes of the adjacent speakers make to be a prescribed angle and connecting correction filters to the respective speakers. SOLUTION: The angle θ which the axes P of the adjacent speakers 3 make is set to be 63 degrees. The correction filter is provided so that sound pressure becomes higher as the frequency becomes higher in S1 having a largest inclination characteristic and a curve in the inclination characteristic can maintain flatness. Since the centers of the adjacent speakers 3 are placed from a measuring device S1 by prescribed distances, sound which is simultaneously radiated from the speakers 3 generate the shift of wavelengths before and behind distance and they interfere one another. Thus, high band rise in the correction filler is suppressed and approximate flatness is kept even in a front characteristic.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wide directional characteristic loudspeaker used for a speaker for HiFi audio or acoustic measurement, and more particularly to a speaker having a plurality of loudspeakers arranged on a peripheral surface of a polyhedron or a sphere so as to improve quality in various directions. The present invention relates to a loudspeaker having a wide directional characteristic capable of hearing the sound of a sound.

[0002]

2. Description of the Related Art Conventionally, as this kind, there is one disclosed in Japanese Utility Model Laid-Open No. 31105/1984.

In this technique, a unimorph vibrator and a diaphragm are arranged on each surface of a regular dodecahedron, which is a polyhedron, so that sounds can be heard from various directions around the polyhedron.

[0004]

However, it has been known that a loudspeaker causes high-frequency attenuation except for the front characteristic on the axis, and a unimorph vibrator and a vibrator are provided on each surface of the polyhedron as in the prior art. In the case where the plate is arranged, the unimorph oscillators and the like are inevitably arranged not at the same plane but at mutually inclined positions. It is difficult to hear high-quality sound from low frequency to high frequency at all positions on the entire circumference of the apparatus, except in front of the line where high frequency attenuation occurs.

[0005] HiFi loudspeakers and the like are required to have a frequency flatness in which the sound pressure is kept constant even when the frequency is changed, and loudspeakers dedicated to acoustic measurement are required to have a frequency flatness and a non-directionality. However, no countermeasures have been taken against the high-frequency attenuation due to the loudspeakers being arranged in such an inclined manner.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a wide directional characteristic loudspeaker capable of obtaining a uniform sound pressure from a low frequency to a high frequency all around the device.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, a plurality of loudspeakers are disposed on a peripheral surface of a polyhedral or spherical loudspeaker main body, and the adjacent loudspeakers are provided. Has a predetermined angle, a correction filter is connected to each speaker, and the correction value of the correction filter is set so that flatness of sound pressure can be obtained at each position around the main body of the loudspeaker. A wide directional characteristic speaker is characterized.

[0008]

Embodiments of the present invention will be described below.

1 to 8 show an embodiment of the present invention.

First, the configuration will be described. Reference numeral 1 in FIG. 2 denotes a wide directivity loudspeaker.
Has a regular dodecahedral loudspeaker body 2 as a "polyhedron", and a plurality of coil speakers 3 as "speakers" are provided on each surface of the body 2 in total. As shown in FIG. 3, each of the speakers 3 has an axis P passing through the center O of the loudspeaker body 2 and an adjacent coil speaker 3.
The angle θ formed by each axis P is 63 ° in this embodiment.
It has become.

As shown in FIG. 1, four of these coil speakers 3 are connected in series, and these are connected in parallel in three rows. A correction filter 4 including resistors R1 and R2 and capacitors C1 and C2 is connected between the speakers 3 and an amplifier (not shown).

The correction filter 4 includes resistors R1, R2
The values (correction values) of the capacitors C1 and C2 are set such that flatness of sound pressure can be obtained at each position around the loudspeaker body 2. That is, as shown in FIG.
The measurement position S1 which is about 50 cm away from the vertex between the adjacent coil speakers 3 is a position having the maximum inclination characteristic, and when the correction filter 4 is not provided,
As shown in FIG. 5, a characteristic curve P1 of frequency and sound pressure is
As the frequency increases, the sound pressure decreases. For this reason, as shown in FIG. 6, by using the correction filter 4 in which the sound pressure increases as the frequency increases, the characteristic curve P2 in the inclination characteristic can be maintained flat as shown in FIG. Is set.

Since the attenuation rate here is determined by the angle θ formed by the axis P of the adjacent coil speaker 3 and the characteristics of the coil speaker 3, the correction value of the correction filter 4 is appropriately determined according to the attenuation rate. Is set.

Thus, a flat characteristic curve P2 can be obtained even at an oblique position of the coil speaker 3, and good sound quality can be obtained at all positions around the device.

As shown in FIG. 7, at the measurement position (S2) on the axis P of the coil loudspeaker 3, the coil loudspeaker 3 is set so as to maintain flatness without the correction filter 4 interposed therebetween. Therefore, when the correction filter 4 is interposed, there is a concern that the sound pressure may not be able to maintain flatness where the frequency is high. However, flatness can be maintained on the axis P for the following reasons.

That is, as shown in FIG. 7, the waveform T1 of the sound from the center speaker 3 at a high frequency (here, about 2.4 kHz) at the measurement position S2 on the axis P of the coil speaker 3 is shown in FIG. 8 (a),
The waveform T2 of the sound from the speakers 3 on both sides is shown in FIG.
(B). 7, the centers of the coil speakers 3 on the center and on both sides thereof are
Since the sounds emitted from the speakers 3 at the same time are separated from each other by about 75 mm from the measuring device S2, there is a wavelength shift before and after the separation distance, and here, a phase shift of 180 ° causes interference with each other. As a result, an increase in the high frequency range due to the correction filter 4 is suppressed, and the flatness of the front characteristics is substantially maintained. However, this interference frequency differs depending on the individual frequency characteristics of the coil speaker 3.

By providing the correction filter 4 in this manner, even if the frequency changes, the flatness of the sound pressure level can be maintained in the inclination characteristic, and thus the wide directional characteristic speaker 1 is provided.
Can be made closer to the actual sound over the entire circumference of.

Therefore, the wide directional characteristic speaker 1 is HiFi
By using it for audio and sound measurement and as other loudspeakers, it is possible to widely provide market users such as industrial speakers with excellent sound reproduction and accurate sound stages.

That is, the wide directivity characteristic loudspeaker 1 of the present invention can obtain the same sound fidelity everywhere in the indoor sound field, and as a result, a good stereo image enlarged area is formed. This provides satisfactory acoustic fidelity and relieves the listener from having to sit at only one "listening point". This results in a uniform 360 ° horizontal and vertical dispersion of the wide directivity loudspeaker 1 of the present invention, which provides a full effective listening range of the listening area with minimal early reflections on the floor and ceiling. .

Further, the wide directivity characteristic loudspeaker 1 of the present invention comprises:
It develops the correct total reverberation field in a room both spatially and spectrally, and is not affected by the deterioration of the backside characteristic of conventional directional front-emitting speakers, but by the room itself. The effect of minimizing the perceived sound even with the accompanying sound is obtained.

Further, resistors R1 and R2 and a capacitor C
A correction filter 4 having a very simple structure composed of C1 and C2
You only need to use one place. Further, since the correction filter 4 is provided in the main body 2 of the loudspeaker, no special filter or preamplifier is required outside, so that the handling can be simplified.

In the above embodiment, the coil speaker 3 is used as a speaker, but the present invention is not limited to this, and a capacitor speaker or the like may be used. The "correction filter" of the present invention is not limited to the above-described embodiment, and the number of capacitors and resistors differs depending on the type of speaker, and a coil or the like may be used.
In any case, it is sufficient if the flatness of the frequency characteristics can be maintained. Furthermore, in this embodiment, the main body of the loudspeaker is formed in a regular dodecahedron, but is not limited to this.
The number of surfaces may be larger or smaller, and a sphere may be used. However, a polyhedron or a sphere having 12 or more polygons can reduce the angle formed by the axes of the adjacent speakers, so that the inclination characteristics can be reduced accordingly, so that the amount of correction by the filter can be small and flatness can be maintained more.

[0023]

As described above, according to the first aspect of the present invention, by providing the correction filter, the flatness of the sound pressure level can be maintained in the inclination characteristic even when the frequency changes. Therefore, the sound can be made closer to the actual sound over the entire circumference of the wide directivity speaker. Therefore, by using the wide directional characteristic loudspeaker for HiFi audio and sound measurement and other loudspeakers, it is possible to provide excellent sound reproduction and accurate sound stage to market users such as industrial speakers widely. .

Further, the wide directivity characteristic loudspeaker of the present invention develops a correct total echo field in a room both spatially and spectrally, and has a rear characteristic such as a conventional directional front emission type speaker. This has a practically useful effect that an effect of minimizing the sense of hearing can be obtained even with the generation of incidental sound due to the room itself without accompanying the bad sound deterioration accompanying the deterioration.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a wide directivity characteristic loudspeaker according to an embodiment of the present invention.

FIG. 2 is a front view of the wide directional characteristic loudspeaker according to the embodiment;

FIG. 3 is a sectional view taken along line AA of FIG. 2 according to the embodiment;

FIG. 4 is a graph showing a relationship between a sound pressure and a frequency at which a filter of the wide directivity characteristic loudspeaker according to the embodiment is provided.

FIG. 5 is a graph corresponding to FIG. 4 when the filter according to the embodiment is not provided.

FIG. 6 is a graph showing a relationship between a sound pressure and a frequency of the filter according to the embodiment.

FIG. 7 is an explanatory diagram when the measurement position according to the embodiment is on the axis of the coil speaker.

FIG. 8 is a diagram showing a waveform at a measurement position in FIG. 7 according to the same embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wide directional characteristic loudspeaker 2 Main loudspeaker 3 Coil speaker (speaker) 4 Correction filter

Claims (1)

[Claims] A plurality of speakers are disposed on a peripheral surface of a polyhedral or spherical loudspeaker main body, the axes of adjacent speakers have a predetermined angle, and a correction filter is connected to each of the speakers. A wide directional characteristic loudspeaker, wherein the correction value of the correction filter is set such that flatness of sound pressure is obtained at each position around the loudspeaker body.