JPH0548498U - Speaker device - Google Patents

Abstract

(57) [Abstract] [Objective] A loudspeaker device having a wide directivity on the front side and a low sound pressure on the rear side is realized to prevent howling without deteriorating acoustic characteristics such as sound image localization. [Structure] In the speaker cabinet 20, a tweeter 22, a squawker 23, and a woofer 24, each having a relatively wide directivity, are provided on the front side (listener side) as main speakers. On the back side thereof, a sound pressure canceling speaker 26 having a relatively narrow directivity is arranged in a direction opposite to the sound emitting direction of the main speakers 22 to 24 so as not to adversely affect the front reproduced sound. The cancellation condition setting circuit 36 uses the main speakers 22 to 24.
A signal having a phase opposite to that of the sound that is generated from the sound and rotates to the back side thereof is generated and sounded from the sound pressure canceling speaker 26. As a result, the sound that turns to the back side is canceled and the sound pressure on the back side is reduced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a speaker device, which makes it possible to lower the back side sound pressure while ensuring a wide directivity on the front side.

[0002]

[Prior Art]

 Generally, a PA (loudspeaker) speaker device for a stage is installed on the left and right front of the stage 10 as shown in FIG. The vocalist 16 is located centering on the rear center of these speaker devices 12 and 14, and the installation positions of main musical instruments are also the same. In this case, in particular, those that transmit sound using a microphone, such as vocals and acoustic musical instruments, require a loud sound (PA), so that the loudspeakers 12 and 14 produce a louder sound.

A problem that always arises in such an arrangement is howling that occurs when the sounds from the speaker devices 12 and 14 rotate to the rear side and are positively fed back to the microphone. In order to prevent this howling, it is desired that the speaker devices 12 and 14 for the stage have low sound pressure on the player side and high sound pressure on the audience side. In order to achieve this, the horn type speaker has been conventionally devised so that the directional characteristics are directed forward as much as possible.

[0004]

[Problems to be solved by the device]

 However, in this case, not only the directivity but also the fidelity are not necessarily all favorable, and there is a drawback that the sound image localization is deteriorated due to the excessive directivity.

Therefore, it is ideal to have a wide directivity on the front surface so that the sound pressure is not transmitted to the rear surface. However, if a structure having a wide directivity on the front surface is used, it is generally arranged on the rear surface. However, since it has a wide directional pattern, it has not been possible to obtain such ideal characteristics.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a speaker device having wide directivity on the front surface and capable of reducing the sound pressure on the back surface.

[0007]

[Means for Solving the Problems]

 This invention is directed to a main speaker that is arranged with the sound emission direction facing the listener, and a sound that is arranged on the back side of the main speaker with the sound emission direction oriented substantially opposite to the main speaker. A speaker for pressure cancellation, an acoustic signal supply means for the main speaker that supplies an acoustic signal to the main speaker, and a sound generated by the main speaker and having a phase approximately opposite to that of the sound that circulates to the back side of the main speaker. The sound pressure canceling speaker acoustic signal supplying means for supplying the sound pressure canceling speaker with an acoustic signal to be emitted from the speaker.

[0008]

[Action]

 According to this invention, the sound emitted from the main speaker and circling to the back side thereof is canceled by the sound emitted from the sound pressure canceling speaker, so that even if the main speaker having wide directivity is used on the front side, The sound pressure on the side can be reduced, and howling can be prevented without degrading acoustic characteristics such as sound image localization.

[0009]

【Example】

 An embodiment of the speaker device of the present invention is shown in a side sectional view in FIG. The speaker cabinet 20 is a tweeter 22 having a relatively wide directivity (that is, a desired sound image localization and other acoustic characteristics can be obtained) and a squawker as main speakers whose sound emission direction is directed to the front side (listener side). 23 and a woofer 24 are provided. On the back side, a sound pressure canceling speaker 26 (for example, a horn speaker) having a relatively narrow directivity is provided in a direction opposite to the sound emitting direction of the main speakers 22 to 24 so as not to adversely affect the front reproduced sound. It is arranged toward.

An acoustic signal output from the drive signal source (power amplifier) 28 (a signal obtained by amplifying a vocal or musical instrument sound picked up by a microphone on the stage for loud sound) constitutes an acoustic signal supply means for a main speaker. The signal is supplied to each of the main speakers 22, 23 and 24 through the signal path 30 to produce a sound and the sound is amplified. The networks 32 and 34 inserted in the signal paths to the tweeter 22 and the squawker 23 are the same as those used in the conventional speaker device (the speaker device without the sound pressure canceling speaker 26).

Further, the acoustic signal output from the drive signal source 28 is supplied to the sound pressure canceling speaker 26 through the signal path 32 constituting the sound signal canceling speaker acoustic signal supplying means to be sounded. In the middle of the signal path 32, a canceling condition setting circuit 36 is inserted for making a sound having a phase substantially opposite to that of the sound emitted from the main speakers 22 to 32 and wrapping around to the back side thereof. The cancellation condition setting circuit 36 can be configured by connecting in series a BPF (band pass filter) whose band and level are variable and a phase controller (phase shifter) whose phase can be arbitrarily changed. In that case, the BPF extracts a band component that easily causes howling, and the phase controller adjusts the phase component of the extracted band component to produce a sound signal that emits a sound having a phase almost opposite to that of the sound that wraps around to the back side. To create.

Further, if the cancellation condition setting circuit 36 is configured by a graphic equalizer type adjuster and the phase can be controlled for each frequency band, the sound circling to the back side can be canceled over a wide frequency band. it can.

FIG. 3 is a plan view showing how sound is propagated by the speaker device 1 shown in FIG. Solid arrows represent sounds from the main speakers 22, 23 and 24, and dotted arrows represent sounds from the sound pressure canceling speaker 26. The sounds from the main speakers 22 to 24 have a relatively wide directivity and are amplified toward the audience. The sound pressure canceling speaker 26 has a relatively narrow directivity and is emitted toward the vocalist or musical instrument on the stage.

A part of the sound generated from the main speakers 22 to 24 goes to the back side thereof, but the sound from the sound pressure canceling speaker 26 (especially the sound in the band in which howling is likely to occur) has an opposite phase. Since it has become, it is counteracted and weakened. If the volume from the sound pressure canceling speaker 26 is made equal to the volume of the sound rotating to the back side, it can be almost completely canceled.

A directional characteristic (sound pressure distribution characteristic: a line in which the same sound pressure is plotted) by the speaker device 1 of FIG. 1 is shown by a solid line in FIG. The dotted line in FIG. 4 shows the directional characteristic when the sound pressure canceling speaker 26 is not provided. According to this, by providing the sound pressure canceling speaker 26, it is possible to reduce the sound pressure on the rear side while ensuring a wide directivity to the front, and howling without deteriorating acoustic characteristics such as sound image localization. Can be prevented.

[0016]

[Example of change]

 In the above-described embodiment, the sound pressure canceling speaker 26 is arranged toward the side opposite to the main speakers 22 to 24. However, as shown in FIG. 5, the sound pressure canceling speaker 26 is placed in the central direction of the stage 10. It can also be arranged diagonally rearward. Further, the sound pressure canceling speaker 26 can be arranged in the cabinet so that its sound emitting direction is variable.

Further, although the main speakers 22 to 24 and the sound pressure canceling speaker 26 are arranged in the same cabinet 20 in the above embodiment, they may be arranged in different cabinets.

[0018]

[Effect of the device]

 As described above, according to the present invention, the sound emitted from the main speaker and circling to the back side thereof is canceled by the sound emitted from the sound pressure canceling speaker, so that the main speaker having a wide directivity on the front surface is provided. Even when used, the sound pressure on the back side can be lowered, and howling can be prevented without deteriorating acoustic characteristics such as sound image localization.

[Brief description of drawings]

FIG. 1 is a side sectional view of a speaker device showing an embodiment of the present invention.

FIG. 2 is a plan view showing an arrangement of conventional PA speakers.

FIG. 3 is a plan view showing how sound is propagated by the speaker device of FIG.

FIG. 4 is a diagram showing a directional characteristic in a horizontal plane in the speaker device of FIG.

FIG. 5 is a plan view showing another embodiment of the present invention.

[Explanation of symbols]

10 Speaker Device 22, 23, 24 Main Speaker 26 Sound Pressure Canceling Speaker 30 Signal Path (Main Speaker Acoustic Signal Supply Means) 32 Signal Path (Sound Pressure Canceling Speaker Acoustic Signal Supply Means)

Claims (1)

[Scope of utility model registration request] 1. A main speaker arranged so as to direct a sound emission direction toward a listener, and a sound emission direction disposed substantially opposite to the main speaker on the back side of the main speaker. A sound pressure canceling speaker, a main speaker sound signal supplying means for supplying a sound signal to the main speaker, and a sound having a phase substantially opposite to that of the sound produced by the main speaker and wrapping around to the back side thereof. And a sound pressure canceling speaker sound signal supplying means for supplying a sound pressure canceling speaker with an acoustic signal to be output from the sound speaker.