JPS603297A - Variable directivity speaker for small sized stereo equipment - Google Patents

Abstract

PURPOSE:To make a directivity characteristic variable by constituting a speaker with the 1st speaker sounding direct sound and the 2nd speaker sounding indirect sound so as to adjust or change over a sounding level. CONSTITUTION:Two left and right speakers 6', 7' are provided in enclosure of an acoustic instrument 1'. The indirect sound is sounded effectively by directing the major axis of the speaker sounding the indirect sound slantingly upward toward the back side. That is, the wall faces and ceiling are utilized effectively so as to increase the level of the indirect sound by taking the start point of the major axis of the speaker sounding the indirect sound as an original and taking an angle between the major axis and the rear face of the enclosure and an angle between the major axis and the upper face of the enclosure as 10-80 deg. respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION (Object of the Invention) The present invention relates to a variable directional speaker for a small stereo device.

(Objective of the Invention) An object of the present invention is to provide a variable directional speaker for use in a small stereo reflex device that provides a sense of spaciousness and presence.

(Contents of Conventional Examples and Their Disadvantages) A large number of compact audio equipment such as small stereo devices and stereo radio cassette tape recorders that can perform stereo reproduction with relative ease have appeared.

Therefore, the distance between the two left and right speakers attached to the audio equipment is generally narrow.

FIG. 1 is a diagram showing an example of a conventional compact audio device.
On the front surface 4.5 of the speakers 2 and 3, the two left and right speakers 6 and 7 are spaced approximately 30 to 100 cm apart, and the opening angle θ between the listener 8 and the speakers 6.7 is the recommended value. The angle is less than 1/2 of a certain 60°, and the localization position of the sound image does not expand further than that.

Figure 2 (A) is a diagram showing the directional characteristics of the speaker at 2kHz when one of the speakers of the audio equipment shown in Figure 1 is used to produce sound, and Figure 2 (B) is a diagram showing the directivity characteristics of the two speakers on the left and right. FIG. 4 is a diagram showing the combined directional characteristics at 2 kHz produced by the two left and right speakers producing sound when in-phase signals are input.

The individual directivity characteristics of the two left and right speakers 6 and 7 provided in the audio equipment 1 are no different from those of general speakers, as shown in FIG. When the same phase signal is input, the two left and right speakers 6 and 7
The synthesized directional characteristics created by sounding the sound act like a tone wave, and the directional characteristics in the horizontal direction become narrow as shown in FIG. 2(B).

Due to the combination of the above-mentioned reasons, the conventional audio equipment 1 has the disadvantage that when listening to stereophonic playback, the effects of expansion and realism are hardly felt.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides two enclosures arranged at a predetermined interval, and a direct A first speaker that produces sound, and one axis located at the rear of the enclosure in the horizontal direction.
Angle ranging from 0° to 80″, vertically 10° to 80″
A new baffle surface is set at J with an angle in the range of
The speaker is configured to have a directional characteristic variable by adjusting or switching the sound levels of the first and second speakers.

(Embodiments of the Invention) In general, in order to obtain a sense of spaciousness and presence in the Jζ una audio equipment shown in FIG. One possibility is to control the volume of indirect sound. Generally, in order to increase the ratio between direct sound and indirect sound, use a horn etc. for the direct sound speaker, narrow the directivity as much as possible, and move the directivity of the indirect sound speaker towards the rear. In order to overcome this problem, it is conceivable to use a large number of speakers to widen the directivity characteristics. However, when installing speakers that produce indirect sounds in a compact audio device 1 as shown in Fig. 1, the installation space and the number of speakers cost 1.
It is difficult to provide the audio equipment 1 with such a large number of subwoofers as described above due to restrictions in terms of performance.

Let's consider where to install a speaker that produces indirect sounds in the audio equipment 1 shown in Figure 1. Figure 3 (A) shows an installation 3tr+- where a speaker that produces indirect sounds can be installed.
This is a diagram for explaining the structure of the speaker, and the surface on which an indirect sound speaker can be installed in the audio equipment 1 shown in FIG.
. Rear surface 9, 10 or upper surface 11
, 12 are provided with speakers that produce indirect sounds, and the rear surface 13,
When in-phase signals are input to the two left and right speakers installed on the top surfaces 11 and 12, the synthesized directional characteristics produced by the two speakers on the left side are shown in Figure 2 (B
), the directivity is narrower than that of a single speaker.Since the sound waves cannot be effectively reflected from walls and ceilings, the direct sound This will lower the ratio of indirect sounds. Also, side 13.14
In the case where the speakers are connected to each other, the sound waves coming around from the speakers installed on the side surfaces 13 and 14 act on the direct sound, which lowers the ratio of indirect sound to direct sound, resulting in a loud noise. Therefore, even if speakers are provided on the rear surfaces 9, 10, the top surfaces 11, 12, or the side surfaces 13, 14, a stereo feeling and a sense of presence cannot be obtained.

Therefore, it is conceivable to direct the main axis of the speaker that produces the indirect sound 8 toward the rear and obliquely upward, so that the indirect sound can be produced more effectively. In other words, Y
Consider X, Y, and Z orthogonal coordinates as shown in FIG. 3(B), which is the Z plane.

Figure 3 (B) is a diagram for explaining the mounting angle of the speaker that produces indirect sounds.
The starting point of the main axis 16 is made to coincide with the origin O of the orthogonal seats X, Y, and Z. The angle between this main axis 16 and the XY plane is α, 1
Let β be the angle formed by the axis 16 and the XZ plane, set the angular range of α as 10°≦α≦80°, set the angular range of β as 10°≦β≦30°, and set the main axis of the speaker within the above angle range. By creating a new baffle surface and attaching a speaker that produces indirect sound to the baffle surface, indirect sound can be effectively provided to the listener. It is possible to increase the level of indirect sound by making effective use of walls and ceilings, and it is possible to not only obtain a sufficient sense of spaciousness and presence, but also to increase the directivity of the indirect sound. By adjusting the level of the speaker that produces the sound, it is possible to create a sound field that the listener prefers.In this case, the control part for adjusting the level of the speaker that produces the indirect sound is integrated with the main unit. It may be provided so that it fits the desired shape, or it may be provided as a separate unit so that the listener can operate it while checking the effect of the handheld device.

FIG. 4(A) shows an embodiment of the variable directional speaker for a small stereo device according to the present invention, FIG. 4(A) is a front view thereof, FIG. 4(B) is a side view thereof, Figure 4 (C)
is a top view thereof. As shown in FIG. 4(A), the acoustic [
Front side 4', 5' of enclosure 2', 3' of koji 1'
The first speakers 6' and 7' are installed to directly produce sound.
, as shown in FIGS. 4(B) and 4(C), in order to maximize the indirect sound level at the listening position of the second speakers 17 and 18 that produce indirect sounds,
Pronounce the indirect sound in the X, Y, Z rectangular coordinates shown in J
The starting point of the main axis 16 of the speaker is set to the orthogonal coordinates X, Y,
Set the angle α between the main axis 16 and the XY plane, etc., and the angle β between the main axis 16 and the YZ plane to α=41°, β=25°, and make the angles as described above. A new baffle surface is provided so that the main axis of the speaker faces, and speakers 17 and 18 for producing indirect sound are mounted on that baffle surface so that their upper axes are not parallel.

Next, FIG. 5 shows how the anti-aJ sound is transmitted by the above-mentioned audio equipment 1'. As shown in FIG. 5, the acoustic equipment 1' placed on the floor 19 generates sound waves 20 from speakers 17 and 18 that emit indirect sounds, which are reflected on the wall 21 and become sound waves 22, which are further reflected on the ceiling 23. The six waves become sound waves 24, which are radiated backward by speakers 17 and 18 that produce indirect sounds, change their direction, and are transmitted to the listener 8. Note that the values of α=41° and β=25° in the above-mentioned embodiment are examples in which good results were obtained within the angle range of α and β described above.

Figure 6 shows the circuit of a remote control device that switches or continuously varies the indirect sound level and direct sound level and adjusts the level at the listening position to suit the room, source, and listener's preferences. A) Shown in (B). Figure 6 (A) shows an example of a remote control circuit that can continuously vary the level of a speaker that produces indirect sound, and Figure 6 (B) shows an example of a simple remote control circuit. This figure shows an example of a remote control circuit that can change the level of a speaker that produces indirect sounds in three stages.

In Figure 6 (A), only the remote control circuit of one channel of the audio equipment 1' is shown;
5 is a signal input terminal, 26 is an amplifier, 27 is a seat control circuit, 28 is an input terminal, 29 is a direct sound output terminal, 30 is a limiter, and 31 is an indirect sound output terminal. The signal input terminal 25 is connected to a signal input terminal 28 of a remote control circuit 27 via an amplifier 26, and the direct sound output terminal 29 is connected to a speaker 6'' that produces direct sound after passing through a limiter 30. , the indirect sound output terminal 31 is connected to the speaker 17 (which is connected) that produces indirect sound.

The remote control circuit 27 is a changeover switch 32a.
32c, 32c' and limiters 33, 34, and the changeover switches 32a to 32c, 32c' are interlocked switches, and have three modes: t-do which produces only direct sounds, mode which produces only indirect sounds, and direct sound. It is designed to switch between three modes: a mode that continuously mixes indirect sounds, and a mode that continuously mixes indirect sounds. The limiters 33 and 34 are provided to adjust the levels of direct and indirect sounds when they are pronounced simultaneously. Further, the limiter 30 is inserted in order to limit the level of the speaker that directly produces the sound because the level of the speaker that directly emits the sound is generally heard at a listening position.

Remote control circuit 21' shown in FIG. 6(B)
is a simple remote control circuit that allows you to set the indirect sound level to three modes: maximum, intermediate, and minimum using a switch 32'.
A to 32'c and 32'c' are selected, and the intermediate level is set by limiters 33' and 34'.

(Effects of the Invention) Since the present invention has the above-described configuration, it has the advantage that by varying the directional characteristics, the sense of spaciousness and presence desired by the listener can be obtained.

[Brief explanation of the drawing]

Figure 1 shows an example of a conventional compact audio device.
Figure 2 (A) is a diagram showing the directional characteristics of the speaker at 2kHz when one of the speakers of the audio equipment shown in Figure 1 is emitting sound, and Figure 2 (B) is a diagram showing the same phase for the two left and right speakers. Figure 3 (A) is a diagram showing the directional characteristics at a synthesized frequency of 2 kHz created by the two left and right speakers producing sound when a signal is input. Figure 3 (B) is a diagram to explain the mounting angle of the speaker that produces indirect sound, and Figures 4 to 6 are diagrams showing the variable directivity for a small stereo system according to the present invention. Fig. 4(A) is a front view of the speaker, and Fig. 4(B) is a front view thereof.
) is a side view, FIG. 4(C) is a top view, and FIG. 5 does not show how the reflected sound of the audio equipment shown in FIG. 4 is transmitted.
Figure 6 (A) (B) shows the circuit of the remote control device.
Shown below. Figure 6 (A) is a diagram showing an example of a remote control circuit that can continuously vary or switch the level of a speaker that emits direct sound and a speaker that emits indirect sound, and Figure 6 (B) is a simplified diagram. This shows an example of a type of remote control circuit that switches the level of the speaker that produces direct sound and the speaker that produces indirect sound into three levels.
FIG. 3 is a diagram illustrating an example of a remote control circuit that can be changed; 1, 1'...Audio equipment, 2, 3...Encloser, 4, 5...Front side of audio equipment 1, 6, 6', 7, 7'...Speaker that produces direct sound,
8... Listener, 9.10... Rear of audio equipment 1, 1
DESCRIPTION OF SYMBOLS 1, 12...Top surface of the audio equipment 1, 13, 14...Side surface of the audio equipment 1, 15...Speaker, 16...Main shaft, 17, 18...
・Speaker that produces indirect sounds, 19...floor, 20...
・Sound wave, 21...Wall, 22...Sound wave, 23...Ceiling, 24...Sound wave, 25...Signal input terminal, 26.
...Amplifier, 27, 27'...Remote J control circuit, 28...Input terminal, 29...Direct sound output terminal, 30...Limiter, 31...Indirect sound output terminal, 32
a to 32c, 32c', 32'a to 32'c, 32'c'... changeover switch, 33, 33', 34, 34'... limiter. Patent Applicant: Japan Victor Co., Ltd. Representative: Ichiro Anamichi Procedural Amendment September 20, 1980 Patent Application No. 110483 2 Title of Invention: Variable Directional Speakers for Small Stereo Devices 3, Person Who Makes Amendment Case Relationship Patent applicant address 3-12 Moriya-cho, Kanayō-ku, Yokohama-shi, Kanagawa Prefecture Name (432) Victor Japan Co., Ltd. Voluntary Amendment 5, Full text of the specification subject to the amendment and drawings 7, Contents of the amendment (1) Full text of the specification Correct it as shown in the attached document. (2) Boxes 3 (B), 4 (B) and 4 (
Correct C) as shown in the attached sheet. Description 1, Title of the Invention Variable Directional Speaker 2 for Small Stereo Devices, Claims Two enclosures arranged at a predetermined interval, and a direct sound emitting device provided in front of each of the enclosures. Install the first speaker and the rear of each enclosure so that the main axis of the speaker is parallel to the main axis of the Go 821 speaker.
Angle in the range of 800, vertically upwards from 10°
A new baffle surface is set so as to have an angle in the range of 80', and a second speaker is mounted on the baffle surface and produces indirect sound, and the sound generation level of the first and second speakers is By adjusting or switching the
Variable directional speaker for small stereo equipment with variable directional characteristics. 3. Detailed Description of the Invention (Object of the Invention) The present invention relates to a variable directivity speaker for a small stereo device. (Object of the Invention) An object of the present invention is to provide a variable directional speaker for a small stereo device that provides a sense of spaciousness and presence. (Contents of Conventional Examples and Their Disadvantages) Many compact audio devices, such as small stereo devices and stereo radio cassette tape recorders, that can perform stereo playback relatively easily have appeared. Therefore, the distance between the two left and right speakers attached to the audio equipment is generally narrow. FIG. 1 is a diagram showing an example of a conventional compact audio device.As shown in FIG. is set at about 30 to 100 Cm, the aperture angle θ between the listener 8 and the speaker 6.7 is less than the recommended value of 600 cm, and the localization position of the sound image does not expand beyond that. do not have. Figure 2 <A> is a diagram showing the directional characteristics of the speaker at 2kHz when one of the speakers of the audio equipment shown in Figure 1 is emitted, and Figure 2 (B> is a diagram showing the in-phase characteristics of the two left and right speakers. It is a diagram showing the directional characteristics at a synthesized frequency of 2 kHz created by the sound produced by the two left and right speakers when a signal of As shown in Figure 2 (A), there is no difference between ordinary speakers, but two left and right speakers 6.7
When an in-phase signal is input to the two left and right speakers 6.
The synthesized directional characteristics produced by the sound produced by 7 act like a tone wave, and the directional characteristics in the horizontal direction become narrow as shown in FIG. 2(B). Due to the combination of the above-mentioned reasons, the conventional sound system has a disadvantage in that even when listening to sound reproduced in stereo with the 11-device 1, the effects of spaciousness and realism are hardly felt. (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides two enclosures arranged at a predetermined interval, and a direct sound sensor provided in front of each of the enclosures. 1st to pronounce
a speaker at the rear of each of the enclosures, with the main axis of the speaker facing outward in a range of 100 to 80 degrees and vertically upward so that the main axis of the speaker is horizontally opposite to the main axis of the first speaker. A new baffle surface is set so that the angle ranges from 10° to 80' towards the
The second speaker is attached to the baffle surface and produces indirect sound, and the directivity characteristics can be varied by adjusting or switching the sound levels of the first and second speakers. (Embodiment of the Invention) In general, in an audio device as shown in Fig. 1, in order to obtain a sense of spaciousness and presence, a speaker that produces indirect sound is provided in addition to a speaker that produces direct sound. One possibility is to control the volume of the sound. IC1 Generally, in order to increase the ratio of direct sound to indirect sound, use a horn etc. for the direct sound speaker, narrow the directivity as much as possible, and move the directivity of the indirect sound speaker to the rear. In order to achieve this, it is conceivable to use a large number of speakers to widen the directivity characteristics. However, when installing speakers that produce indirect sound in the compact audio equipment 1 shown in Fig. 1, the installation space and the number of speakers are subject to cost constraints, so it is necessary to install a large number of speakers as described above. It is difficult to provide it in the audio equipment 1. Consider the location where a speaker for producing indirect sound is installed in the audio equipment 1 shown in FIG. 1. FIG. 3(A) is a diagram for explaining the aspect of an enclosure in which a speaker for producing indirect sound can be provided, and the speaker for producing indirect sound can be provided in the audio equipment 1 shown in FIG. 1. The surfaces include the rear surface 9, 10 of the audio equipment 1, which is the back surface of the front surface 4.5 where the speaker 6.7 that produces direct sound is provided, the top surface 11° 12 of the audio equipment 1, and the side surface 13 of the audio equipment 1. These are the left and right sides of .14. Rear surface 9, 10 or upper surface 11.12
A speaker that produces an indirect sound is installed in the rear panel 9.10 or the top panel 11.12, and when the same phase signal is input to the two left and right speakers installed on the rear panel 9.10 or the top panel 11.12, the two left and right speakers produce a synthesized directional sound. The characteristic is the directional characteristic shown in Figure 2 (B), which is narrower than the directional characteristic of a single speaker, and the sound waves cannot be effectively reflected from walls and ceilings, so it is difficult to respond to direct sound. This will lower the indirect sound ratio. Furthermore, when speakers are provided on the side surfaces 13 and 14, the sound waves coming around from the speakers provided on the side surfaces 13 and 14 act on the direct sound, resulting in a lower ratio of indirect sound to direct sound. Therefore, the rear surface 9,1
Even if speakers are provided on the top surface 11.12 or the side surface 13.14, a stereo feeling and a sense of presence cannot be obtained. Therefore, it is conceivable to direct the main axis of the speaker that produces the indirect sound toward the rear and obliquely upward, and to reciprocally direct the main axis outward to produce the indirect sound more effectively. In other words, the third
The plane parallel to the rear surfaces 9 and 10 of the enclosures 2 and 3 of the audio equipment 1 shown in Figure (A) is the YZ plane, and the side surface 13
．． 14 as shown in FIG. 3(B), where the plane parallel to XZ plane is the Consider Y and Z rectangular coordinates. FIG. 3(B) is a diagram for explaining the angle at which the speaker for pronouncing the indirect name is mounted. The starting point of the main axis 16 of the speaker 5 for producing the indirect name is the origin O of the orthogonal coordinates X, Y, and Z. match. This main shaft 16
The angle between the main axis 16 and the YZ plane is α, the angle between the main axis 16 and the YZ plane is β, and the angular range of α is set as 100≦α≦80°, and the angular range of β is set as 10°≦β≦80°, By providing a new baffle surface such that the main axis of the speaker faces within the above-mentioned angular range and mounting a speaker that produces indirect sound on the baffle surface, indirect sound can be effectively provided to the listener. In other words, it is possible to expand the directional characteristics synthesized by the sounds of the left and right speakers, make effective use of walls and ceilings, increase the level of indirect sound, and obtain a sufficient sense of spaciousness and presence. In addition, by adjusting the input level of the speaker that produces the indirect sound and the input level of the speaker that produces the direct (direct) sound on the front of the enclosure, it is possible to create a sound field that the listener prefers. . In this case, the control part for adjusting the level of the speaker that produces the indirect sound may be provided so as to be integrated with the main body, and the control part may be provided so that it can be operated while checking the effect at the listener's hand. It may be a separate body. FIG. 4 shows an embodiment of the variable directional speaker for a small stereo device according to the present invention. FIG. 4(A) is a front view thereof, FIG. Figure 4 (
C) is its top view. As shown in Figure 4 (A), the sound is 9mW! A' enclosure 41-2'. First speakers 5' and 7' for producing direct sounds are installed on the front surfaces 4' and 5' of 3', and second speakers for producing indirect sounds are installed, as shown in Fig. 4(B) and (C). In order to maximize the level of indirect sound at the listening position, the speakers 17 and 18 of FIG. In the X, Y, Z rectangular coordinates, the starting point of the main axis 16 of the speaker that produces the 11 sounds is the X, Y, Z rectangular coordinate. The angle α between the main axis 16 and the XY plane and the angle β between the main axis 16 and the YZ plane are α=51.
° , β = 700, a new baffle surface is provided so that the main Q-axis of the speaker faces at the above-mentioned angle, and on the first surface of the tSS rough, speakers 17 and 18 that produce indirect sounds are placed with their main axes parallel to each other. Attach it so that it does not become That is, as shown in FIG. 4(C), the speakers 17, 18 are mounted so that their main axes face outward. Next, we will explain how the reflected sound of the above-mentioned audio equipment 1' is transmitted.
As shown in the figure. As shown in FIG. 5, speakers 17 and 18 emit indirect sounds in the audio equipment 1' placed on the floor 19.
The sound wave 20 emitted from the wall 21 is reflected by the wall 21 and becomes the sound wave 22
Then, the sound wave 24 is further reflected from the ceiling 23 and radiated backward by the speakers 17 and 18 that produce indirect sound, and then is transmitted to the listener 8 after changing its direction. Note that the values of α-51° and β=700 in the above-mentioned examples are examples in which good results were obtained within the angle ranges of α and β described above. Figure 6 (A) shows the circuit of a remote control device that can switch or continuously vary the indirect sound level and direct sound level and adjust the level at the listening position to suit the room, source, and listener's preferences. ) (B). Figure 6 (Δ) shows an example of a remote control circuit that can continuously vary the level of a speaker that produces indirect sound, and Figure 6 (B) shows an example of a simple remote control circuit. , is a diagram showing an example of a remote control circuit that can change the level of a speaker that produces indirect sound in three stages. Figure 6 (A) shows only the remote control circuit of one channel of the audio equipment 1', 25 is a signal input terminal, 26 is an amplifier, 27 is a remote control circuit, 28 is its input terminal, and 29 is a direct control circuit. A sound output terminal, 30 is a limiter, and 31 is an indirect sound output terminal. Signal input terminal 2
5 is a remote control circuit 27 via an amplifier 26
The direct sound output terminal 29 is connected to the input terminal 28 of the speaker 6" which outputs the direct sound after passing through the limiter 30.
The indirect sound output terminal 31 is connected to a speaker 17 that produces indirect sound. The remote control circuit 27 is a changeover switch 32a.
32c, 32c' and limiters 33.34, and the changeover switches 32a to 32c, 32c' are interlocked switches that can be used to select between a mode in which only direct sounds are produced, a mode in which only indirect sounds are produced, and a mode in which direct and indirect sounds are produced. It is designed to switch between three modes: a mode in which the sound is mixed continuously; The limiters 33 and 34 are provided to adjust the levels of the direct sound and the indirect sound when the direct sound and the indirect sound are generated simultaneously. Further, the limiter 30 is inserted in order to limit the level of the speaker that directly produces the sound because the level of the speaker that directly emits the sound is generally heard at a listening position. Remote control circuit 27' shown in FIG. 6(B)
is a simple remote control circuit that allows you to set the indirect sound level to three modes: maximum, intermediate, and minimum using a switch 32'.
A to 32'c, 32'c' are selectively covered, and the intermediate level is set to limiters 33', 33'.
Settings are made using 4'. (Effects of the Invention) Since the present invention has the above-described configuration, it has the advantage that by varying the directional characteristics, a sense of spaciousness and presence desired by the listener can be obtained. 4. Brief explanation of the drawings Figure 1 shows an example of conventional compact audio equipment.
Figure 2 (A) is a diagram showing the directional characteristics of the speaker at 2 kHz when one of the speakers of the audio equipment shown in Figure 1 is used to generate sound, and Figure 2 (B) is a diagram showing the directional characteristics of the two speakers on the left and right. Figure 3 (A) shows the directional characteristics of the synthesized 2kHz generated by the two left and right speakers producing sound when the same phase signal is input to the enclosure. Figure 3 (B) is a diagram to explain the mounting angle of a speaker that produces indirect sound, and Figures 4 to 6 are views for explaining the mounting angle of a speaker that produces indirect sound. This shows an example of a directional speaker, and FIG. 4(A) is a front view thereof, and FIG.
B) is a side view, FIG. 4(C) is a top view, FIG. 5 is a diagram showing how the reflected sound of the audio equipment shown in FIG. 4 is transmitted, and FIG. 6(A) is an indirect sound. The figure does not show an example of a remote control circuit that can continuously vary or switch the level of a speaker that produces sound, and FIG. 6(B) is a diagram showing an example of a simple remote control circuit. 1.1'...Audio equipment, 2.2', 3.3'...Encloser-14,4'
, 5.5'...front of audio equipment 1, 6.6', 7
．． 7'... Speaker that produces direct sound, 8... Listener, 9.10... Rear side of audio equipment 1, 11, 12...
・Top surface of audio equipment 1, 13, 14...Side surface of audio equipment 1, 15...Speaker, 16...Main shaft, 17, 18...
・Speaker that produces indirect sounds, 19...floor, 20...
・Sound wave, 21...Wall, 22...Sound wave, 23...Ceiling, 24...Sound wave, 25...Signal input terminal, 26.
...Amplifier, 27, 27'...Remote control circuit. 28... Input terminal, 29... Direct sound output terminal, 30
...Limiter, 31...Indirect pitch j terminal, 32a~
32c, 32c'. 32'a to 32'C, 32'c'... Changeover switch, 33, 33', 34.34'... Limiter. -53': Figure 3 (B') Figure 3

Claims (1)

[Claims] two enclosures arranged at a predetermined interval; and a first enclosure provided in front of the enclosure that produces a direct sound.
A speaker with a main axis at the rear of the enclosure at an angle of 10° to 80° horizontally and 10° vertically.
A new baffle surface is set to have an angle in the range of ~80 degrees, and a second speaker is attached to the baffle surface and produces indirect sound, and the sound output level of the first and second speakers is A variable directional speaker for small stereo equipment whose directional characteristics can be varied by adjusting or switching.