JP2006060330A - Stereo reproducing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stereo reproducing apparatus which can perceive a reproducing sound having a spread even if it is outside a listening area. <P>SOLUTION: The stereo reproducing apparatus includes two speakers 8 and 9 made of oscillating elements 8a and 9a having opening surfaces 8c and 9c for generating the reproducing sound; a speaker cabinet 2 in which respective speakers 8 and 9 are attached together with the opening surfaces 8c and 9c toward a front surface side, and the front surface axes of the speaker cabinets 8 and 9 are crossed and arranged; and two flat surface boards 3 and 4 provided in the speaker cabinet 2 and arranged oppositely to sandwich both the speakers in parallel with the arraying directions of the respective speakers 8 and 9. Particularly, the respective speakers 8 and 9 are arranged so that the part of the oscillating element in the other speaker is included in the designated area made of a predetermined sound pressure level in the reproducing sound by the one speaker. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a stereo playback device, and more particularly to an improvement of a stereo playback device in which two speakers that generate playback sound are attached to a box with an opening surface facing the front side.

  When listening to sound emitted from a sound source such as a violin in a space such as a concert hall at a certain sound receiving point in the space, sound waves are emitted from the sound source in various directions. Only the sound wave propagated through the propagation path to reach is heard as sound at the sound receiving point. The space through which sound propagates is called a sound field. The propagation path from the sound source to the sound receiving point includes a direct path connecting the sound source and the sound receiving point with a straight line and a reflection path reflected on the wall surface.

  The sound reaching the sound receiving point is attenuated and delayed according to the propagation path length. Further, in the case of the sound that has reached through the reflection path, the volume, tone color, and phase are changed according to the material of the wall surface at the time of reflection on the wall surface. For this reason, even when the sound is emitted from the same sound source, the amplitude, frequency, and phase are different for each propagation path when the sound receiving point is reached.

  The listener in the sound field perceives the sound from the sound source as a spread sound by listening to such a sound having a different amplitude or phase for each propagation path at the sound receiving point. A conventional stereo playback apparatus attempts to reproduce a sound with a spread from a sound source as described above by generating a playback sound by two speakers arranged on the left and right.

  FIGS. 15A and 15B are diagrams showing a propagation path when the listener listens to the sound from the sound source. FIG. 15A shows the direct sound from the sound source and the reflection by the wall surface. FIG. 15B shows the left speaker and the right speaker arranged on the left and right as viewed from the listener, and the reproduction sound from each speaker being propagated. Has been. Both speakers are arranged in the same direction, and the left speaker reproduces sound from the left speaker, and the right channel reproduces sound from the right speaker.

  A region on the front side of both speakers and an equal distance from each speaker is a listening area, and the listener can correctly obtain a sound image localization in this listening area. In other words, since the playback sound of the left and right channels released at the same time is heard at the receiving point at the same time, the playback sound can be expanded in the same way as when the direct sound from the sound source and the reflected sound from the wall are simultaneously heard at the receiving point. It can be perceived as a certain sound. However, when the listener is outside the listening area, there is a problem that the reproduced sound cannot be perceived as a broadened sound.

  FIG. 16 is a diagram illustrating a state in which a listener listens to a reproduction sound by a conventional stereo reproduction apparatus. Since the listener P11 in the listening area Q11 has the same distance to each speaker, it is possible to listen to the reproduced sound (direct sound) of the left and right channels simultaneously emitted from each speaker. In contrast, the listener P12 outside the listening area Q11 listens to the reproduced sound simultaneously emitted from each speaker with a time difference. For example, when the listener P12 is closer to the right speaker than to the left speaker, the reproduced sound from the right speaker arrives first.

  At this time, it is perceived that only the reproduced sound from the speaker on the near side is heard by the so-called Haas effect of feeling the direction of the sound toward the sound source that has arrived first. For this reason, the reproduced sound from each speaker cannot be perceived as a wide sound.

  Note that Patent Document 1 discloses a stereo reproduction device in which speakers are arranged on two surfaces adjacent to each other in a box. This stereo reproduction apparatus is intended to improve the directivity of reproduced sound by arranging the speakers in directions different from each other by 90 ° and driving the speakers with different polarities. Therefore, the reproduced sound is not perceived as a widened sound even outside the listening area.

Patent Document 1 describes a stereo device in which two speakers are attached to a sealed cabinet, and both cabinets are arranged facing a listening area. This stereo reproduction apparatus is intended to expand a listening area where a preferable stereo feeling can be obtained by using the directivity of each speaker to reduce the difference in propagation distance at the sound receiving point.
Japanese Patent Laid-Open No. 9-261791

  As described above, the conventional stereo reproduction device has a problem that when the listener is outside the listening area, it is impossible to obtain a wide reproduction sound.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a stereo reproduction apparatus that can perceive a reproduced sound that is wide even outside the listening area. In particular, the present invention provides a stereo playback device that can obtain a rich playback sound similar to the case where a direct sound and a reflected sound from a sound source are simultaneously heard at a receiving point by diffusing the playback sound of each channel. With the goal.

  The stereo playback device according to the present invention is provided with two speakers each having an opening that generates playback sound, and each speaker is mounted with the opening facing the front, and the front axis of each speaker is And a box that is arranged to intersect.

  According to such a configuration, since the two speakers are arranged so that the front axes intersect, the reproduced sound emitted from one speaker can be propagated toward the other speaker. Thereby, since the reproduction sound by one speaker can be reflected by the vibrating body in the other speaker, the reproduction sound by each speaker can be diffused.

  In particular, each of the speakers is configured to be arranged so that a part of a vibrating body in the other speaker is included in a directivity area having a predetermined sound pressure level in a reproduced sound from one speaker. With such a configuration, part of the reproduced sound in the directional area can be reflected by the vibrating body, so that the reproduction sound diffusion effect can be improved.

  In addition to the above-described configuration, the stereo reproduction apparatus according to the present invention includes a speaker having a conical diaphragm, and the speaker in the other speaker is inclined in the directional area of the speaker. And a part of an inclined surface opposite to the one speaker.

  In addition to the above-described configuration, the stereo reproduction apparatus according to the present invention is configured such that each of the speakers is a flat speaker whose vibrating body is a flat diaphragm.

  In addition to the above configuration, the stereo playback apparatus according to the present invention includes playback sound reflecting means that protrudes forward between the speakers in the box and reflects the playback sound from the speakers to the speaker side. Composed.

  In addition to the above configuration, the stereo playback device according to the present invention includes two flat plates provided in the box and arranged to face each other so as to sandwich both speakers in parallel to the arrangement direction of the speakers. Composed.

  In addition to the above configuration, the stereo reproduction apparatus according to the present invention includes a duct that is provided in the box and communicates an air chamber in the box with an external space.

  In addition to the above-described configuration, the stereo reproduction apparatus according to the present invention further includes vibrating body driving means for driving the vibrating body of each speaker based on an input signal, and the input signal based on an audio signal composed of left and right channels. And an input signal generating means for generating. In particular, the input signal generation means is configured to generate an input signal with different phase characteristics between the left and right channels and add a reverberation effect to the reproduced sound.

  According to the stereo playback device of the present invention, the playback sound from one speaker is diffused by reflecting the playback sound from one speaker by the vibrating body of the other speaker. It is possible to obtain a rich reproduction sound similar to that heard at the receiving point at the same time. Accordingly, it is possible to make the listener perceive a wide reproduction sound even outside the listening area.

Embodiment 1 FIG.
1 (a) and 1 (b) are diagrams showing an example of a schematic configuration of a stereo playback device according to Embodiment 1 of the present invention. FIG. 1 (a) shows playback sounds of left and right channels, respectively. FIG. 1B shows a plan view of the speaker cabinet 2 as viewed from the front side of the speaker cabinet 2 in which the two speakers 8 and 9 to be generated are arranged. The stereo playback apparatus 1 according to the present embodiment is a small audio output device that uses a space such as a hall or a hotel lobby as a sound field, and outputs 2-channel stereo playback sound. Here, it is assumed that the reproduced sound is output based on the input signal from the external sound source device. The distance between the speakers 8 and 9 is 1 m or less.

  The speaker cabinet 2 accommodates each speaker 8 and 9, and consists of a rectangular parallelepiped box for forming an air chamber inside. The speaker cabinet 2 is formed with a recess 10 that is recessed toward the back of the box on the front side where the speakers 8 and 9 are arranged. The concave portion 10 includes two inclined surfaces 5 and 6 and a bottom surface 7, and the inclined surfaces 5 and 6 are formed on opposite sides of the box body with the bottom surface 7 parallel to the back surface of the box body interposed therebetween. The speakers 8 and 9 are disposed in the inclined surfaces 5 and 6, respectively. In addition, the box which comprises the speaker cabinet 2 may be a polygon or a circular thing besides the thing whose cross-sectional shape by the horizontal surface is a rectangle.

  Further, on two side surfaces of the speaker cabinet 2 that are parallel to the arrangement direction of the speakers 8 and 9, flat plates 3 and 4 are arranged so as to sandwich both speakers. By providing these flat plates 3 and 4 in the speaker cabinet 2, a horn structure for resonating the reproduced sound from the speakers 8 and 9 can be formed by the flat plates 3 and 4 and the recess 10. With this horn structure, the radiation efficiency of the reproduced sound is improved, so that the stereo reproducing apparatus 1 having good efficiency as a speaker can be obtained.

  Each of the speakers 8 and 9 is an audio output element that outputs a reproduction sound including left and right channels, and each includes a vibrating body 8a and 9a and driving units 8b and 9b. Each drive part 8b and 9b is performing the operation | movement which drives the vibrating bodies 8a and 9a based on an input signal, respectively, for example, consists of a voice coil.

  Each of the vibrating bodies 8a and 9a includes a conical diaphragm having opening surfaces 8c and 9c, respectively, and performs an operation of generating a reproduced sound. Here, cone paper having a circular opening surface is used as the diaphragm.

  By arranging such speakers 8 and 9 on the inclined surfaces 5 and 6 described above, the front axes of the speakers 8 and 9 cross each other on the front side of the speaker cabinet 2. That is, each speaker is mounted with the opening surfaces 8c and 9c facing the front side of the speaker cabinet 2, and the opening surface of one speaker is disposed facing the other speaker side. Here, each speaker 8 and 9 is arrange | positioned in a horizontal surface, and each said front axis cross | intersects in this horizontal surface. The front axis of each speaker 8 and 9 is a straight line perpendicular to the opening surface and is the central axis in the direction of the direction of the reproduced sound to be emitted.

  FIG. 2 is a diagram showing an example of the details of the main part of the stereo playback device of FIG. 1, and shows the state of the speakers 8 and 9 arranged with the opening surfaces facing the speaker sides opposite to each other. . By tilting the opening surface of one speaker toward the other speaker side disposed on the opposite side in the speaker cabinet 2, the reproduced sound emitted from the one speaker can be reflected by the other speaker. That is, since the reproduced sound emitted from one speaker and propagating in the front direction is directed to the other speaker side, a part of the reproduced sound propagating toward the speaker side is reflected by the vibrating body in the other speaker. Can do.

  At that time, since the opening surface of the other speaker is arranged to be inclined toward the one speaker side, the reflection from the one speaker is larger than the reflection by the plane parallel to the arrangement direction of the speakers 8 and 9. Can be reflected toward the speaker. As a result, the reproduced sound from each speaker 8 and 9 can be effectively diffused, so that a rich reproduced sound similar to that obtained by simultaneously listening to the direct sound and the reflected sound from the sound source at the receiving point can be obtained. Can do.

  Here, in order to improve the diffusion effect in the reproduced sound, the speakers 8 and 9 are arranged so that a part of the vibrating body in the other speaker is included in the direction of the reproduced sound by the one speaker. And That is, a part of the vibrating body in the other speaker is included in a range of a predetermined sound pressure level in the reproduced sound and within a range of the directivity angle A2 centered on the front axis A1 in one speaker. Thereby, a part of the reproduced sound in the directional area of one speaker can be reflected by the vibrating body of the other speaker, so that the diffusion effect of the reproduced sound can be improved.

  The directional angle A2 in the directional area of the reproduced sound is an area including the main part of the reproduced sound with respect to the sound pressure level. Specifically, the directional angle A2 is an area where the sound pressure level is ½ or more of the value in the front direction. In this region, the sound pressure energy is ¼ or more of the value in the front direction. Such a directional area is arranged so as to include a part of the inclined surface of the diaphragm of the other speaker, which is opposite to the one speaker.

  FIG. 3 is a diagram showing an example of the reproduction operation in the stereo reproduction device of FIG. 1, and shows a state in which the reproduction sound from one speaker propagates to the listener P2. In the conventional stereo reproduction apparatus, the front area that is equidistant from the left and right speakers is the listening area, and the listener P1 in the listening area correctly obtains the sound image localization. However, the listener P2 outside the listening area cannot obtain the correct sound image localization and cannot hear the reproduced sound as a wide sound. On the other hand, in the present embodiment, by intersecting the front axes of the speakers 8 and 9, a part of the reproduced sound emitted from one speaker is reflected by the other speaker, and this reflected sound and direct sound are reflected. Is heard by the listener P2, so that the reproduced sound can be perceived as a rich sound with a spread.

  Here, it is assumed that the speakers 8 and 9 are arranged so that the intersection A3 of the front axes of the speakers 8 and 9 is in front of the positions of the listeners P1 and P2, thereby making the reproduced sound more effective. Can be diffused.

  FIG. 4 is a diagram showing an example of the sound pressure level of the reproduced sound emitted from the speaker, and the sound pressure level with respect to the front direction of the speaker is shown for each propagation direction. In general, in a speaker having directivity in the front direction, the characteristic curve A4 composed of the sound pressure level for each propagation direction in the reproduced sound has a high level near the front. That is, the sound pressure level is maximum in the direction of the front axis A1 of the speaker. In this characteristic curve A4, the directivity angle A2 is obtained from the range where the sound pressure level is ½ (−6 dB) or more in the direction of the front axis A1.

  In the present embodiment, the reproduction sound from one speaker is reflected by the vibrating body of the other speaker, so that the reproduction sound from each speaker 8 and 9 is diffused. It is possible to obtain a rich reproduced sound having the same spread as when the direct sound and the reflected sound from the sound source are simultaneously heard at the sound receiving point. Accordingly, it is possible to make the listener perceive a wide reproduction sound even outside the listening area.

  In particular, even the listener P2 who is out of the vicinity of the front of the speaker cabinet 2 can hear the reproduced sound of the left and right channels equally by the diffusion effect.

  In the present embodiment, an example in which a conical diaphragm is used as the vibrating bodies 8a and 9a has been described. However, the present invention is not limited to this. For example, a flat speaker made of a flat diaphragm may be used.

  FIG. 5 is a plan view showing another configuration example of the stereo reproduction apparatus according to the present embodiment. In this stereo reproduction apparatus, the flat speakers 11 are arranged on the respective inclined surfaces on the front side of the speaker cabinet. Each flat speaker includes a flat diaphragm 12 and a drive unit 13. Generally, in a speaker having a conical diaphragm (cone speaker), reproduced sound propagates as a spherical wave. On the other hand, in the case of a speaker having a flat diaphragm (planar speaker), reproduced sound propagates as a plane wave. For this reason, the flat speaker is less attenuated by the propagation distance than the cone speaker, and the radiation efficiency in the vicinity of the speaker is good.

  By using such a flat speaker 11, the reproduced sound can be effectively emitted. In particular, since the reproduced sound is reflected by a plane, the controllability in the propagation direction of the reflected sound can be improved. Therefore, a desired diffusion effect can be obtained in the reproduced sound. In addition, cone paper having sound absorption is usually used for the cone speaker. On the other hand, a flat speaker can use a member having excellent sound wave reflection characteristics, for example, a member made of a synthetic resin such as vinyl or polyester as a diaphragm, thereby further improving the diffusion effect of reproduced sound. be able to.

Embodiment 2. FIG.
In the first embodiment, an example in which reproduced sound is reflected and diffused by directing one speaker to the other speaker side has been described. On the other hand, in the present embodiment, a case where a reproduction sound reflecting means is provided between speakers in order to further enhance the reproduction sound diffusion effect will be described.

  6 (a) and 6 (b) are diagrams showing a configuration example of the stereo reproduction device according to the second embodiment of the present invention. FIG. 6 (a) shows the bottom surface 7 between the left and right speakers. The reproduction sound reflecting means 21 provided is shown, and FIG. 6B shows a cross-sectional view of the speaker cabinet 2 as viewed from above. FIG. 7 is a perspective view showing the main part of the stereo reproduction apparatus of FIG. 6, and shows the state of the reproduction sound reflection means 21 composed of two reflection plates 22 and 23. FIG.

  Compared with the stereo playback apparatus 1 (Embodiment 1) of FIG. 1, this stereo playback apparatus 20 is a playback sound composed of two planar reflectors 22 and 23 attached on the bottom surface 7 of the speaker cabinet 2. The difference is that the reflection means 21 is provided.

  The reproduced sound reflecting means 21 is provided on the bottom surface 7 so as to protrude toward the front of the speaker cabinet 2, and performs an operation of reflecting the reproduced sound from one speaker toward the one speaker side. That is, with respect to a vertical plane equidistant from each speaker 8 and 9 including the intersection A3 of the front axes of the speakers 8 and 9, the reproduced sound emitted from one speaker and incident on the reflecting surface of the reproduced sound reflecting means 21 Is reflected to the speaker side. For example, the reproduction sound reflecting means 21 is composed of two reflecting plates 22 and 23 provided for each of the speakers 8 and 9, and is arranged with the reflecting surface inclined toward the front side.

  Here, it is assumed that the reflecting plates 22 and 23 are connected at the apex portion 24 protruding forward, and the cross-sectional shape thereof is V-shaped. Each of the reflection plates 22 and 23 is arranged so that a part of the reflection surface of the reflection plate corresponding to the speaker is included in the reproduction sound directivity area of one speaker. Note that each of the reflection plates 22 and 23 is not provided with a through-hole or the like through which the reproduced sound passes, and all of the reproduced sound incident on the reflecting surface is reflected or absorbed.

  FIG. 8 is a diagram showing the details of the main part of the stereo reproduction device of FIG. 6, in which an intersection A3 of the front axes of the speakers 8 and 9 and an intersection A5 of the boundary line of the directional area are shown. An intersection A3 of the front axes of the speakers 8 and 9 and an intersection A5 of the boundary line (or boundary surface) of the directivity area are formed on the center axis A6 of the two speakers that are equidistant from the speakers 8 and 9. .

  Each reflecting plate 22 and 23 is arranged so that the apex portion 24 is at a predetermined position between A3 and A5. By arranging the apex portions 24 of the reflecting plates 22 and 23 in the directivity area, the reproduced sound from one speaker is reflected to the one speaker side by the reflecting plate on the speaker side. Can diffuse. Further, by arranging the apex portion 24 so as to be closer to the front side than the intersection A3 of the front axes of the speakers 8 and 9, the direct sound in the reproduced sound from one speaker is effectively propagated to the other speaker side. Therefore, the diffusion effect of the reproduced sound by both speakers can be further improved. That is, the reproduced sound that has entered the reflectors 22 and 23 is reflected or absorbed and does not pass through. Therefore, if the apex portion 24 protrudes before the intersection A3, the reproduced sound from one speaker is Propagation directly to the speaker is prevented. For this reason, from the viewpoint of effectively diffusing reproduced sound, it is desirable that the apex portion 24 be on the near side of the intersection A3.

  In the present embodiment, an example in which the reproduction sound reflecting means is made of a flat reflector has been described. However, the present invention is not limited to this, and the reflection that can appropriately reflect the reproduction sound. The member may have another shape.

  FIG. 9 is a diagram showing another configuration example of the stereo reproduction apparatus according to Embodiment 2 of the present invention. In this stereo reproduction device, two reflectors 25 and 26 curved to the back side are arranged between the speakers 8 and 9 as reproduction sound reflection members. In other words, each of the reflection plates 25 and 26 has a reflection surface that is recessed toward the opposite side of the corresponding speaker, and has a shape that improves the reproduction sound diffusion effect by the speaker.

  By adjusting the curved surface shapes of the reflectors 25 and 26, desired radiation characteristics can be obtained in the reproduced sound. In particular, by curving the reflecting surface toward the back side of the speaker cabinet when viewed from the speaker side, the reproduction sound from the speaker is reflected so as to converge on the speaker side, so that the diffusion effect of the reproduction sound can be improved. . That is, it is possible to listen to a wide reproduction sound with a wider area as a listening area.

  FIG. 10 is a diagram showing another configuration example of the stereo reproduction apparatus according to Embodiment 2 of the present invention. In this stereo reproduction apparatus, two reflectors 27 and 28 curved to the front side are disposed between the speakers 8 and 9 as reproduction sound reflection members. That is, each of the reflection plates 27 and 28 has a reflection surface that is recessed toward the corresponding speaker side, and has a shape that improves the diffusion effect of reproduced sound by the speaker.

  Here, when the reflection surface is bent from the speaker side to the front side of the speaker cabinet, the playback sound is reflected so that it converges at the center of both speakers, so if you want to listen to the playback sound spotly It is effective. That is, it is suitable for listening to a wide reproduction sound with a relatively narrow area as a listening area.

  FIG. 11 is a diagram showing another configuration example of the stereo reproduction apparatus according to Embodiment 2 of the present invention. FIG. 12 is a perspective view showing the main part of the stereo reproduction apparatus of FIG. 11, and shows the state of the reproduction sound reflecting means composed of the two reflecting plates 31 and 32 with the front end portion 34 intersecting. .

  In this stereo reproduction apparatus, the two reflectors 31 and 32 are arranged so as to intersect each other. That is, each of the reflectors 31 and 32 has a plurality of comb-like slits, and the reflectors 31 and 32 are arranged so that the comb-like portions are engaged with each other. In this example, comb-like portions are engaged with each other so that slits are formed on the tip side and the root side of the reflecting plates 31 and 32 from the intersecting portion.

  The direct sound from one speaker can be passed to the other speaker side by the slits formed in the reflecting plates 31 and 32. That is, a part of the reproduced sound incident from one speaker on each of the reflection plates 31 and 32 is reflected to the speaker side by the reflecting surface, and the other part can be propagated to the other speaker side by the slit.

  Since the front end portion 34 of each reflector 31 and 32 allows a part of the direct sound from one speaker to pass to the other speaker side by the slit, it protrudes before the intersection A3 of the front axes of the speakers 8 and 9. Can be made.

  By configuring the reproduction sound reflecting means so that the front end portion 34 is positioned in front of the intersection A3, the reflection surface can be enlarged, so that the reproduction sound diffusion effect can be improved.

  FIG. 13 is a perspective view showing another configuration example of the stereo reproduction apparatus according to Embodiment 2 of the present invention. In this example, a large number of slit-like through holes 37 are formed in the reflectors 35 and 36 connected at the apex portion. The through hole 37 is formed over the entire surface of the reflection plates 35 and 36. The material of the members constituting the reflectors 35 and 36 and the shape and number of the through holes 37 are determined according to the required acoustic characteristics. Other configurations of the reflecting plates 35 and 36 are the same as those of the reflecting plates 22 and 23 in FIG.

  A part of the reproduced sound incident from one speaker is reflected to the speaker side, and the other part is passed to the other speaker side through the through-hole 37, so that the peak portions of the reflectors 35 and 36 are passed through the speakers. It can be arranged to protrude forward from the intersection A3 of the front axes of 8 and 9. Accordingly, the reflecting surface can be effectively enlarged, and the reproduction sound diffusion effect can be improved.

  In this embodiment, an example in which the reflector is disposed on the bottom surface has been described. However, the present invention is not limited to this, and the reflector may be removed. Since each reflector can be removed from the speaker cabinet, the reflector can be replaced as necessary with a reflector capable of obtaining a desired diffusion effect, so that the application in the stereo reproduction apparatus can be expanded.

Embodiment 3 FIG.
FIG. 14 is a front view showing a configuration example of the stereo reproduction apparatus according to Embodiment 3 of the present invention. The stereo playback device 40 differs from the stereo playback device 1 of FIG. 1 in that a duct 42 serving as a bass reflex port is provided in front of the speaker cabinet 41. The duct 42 is a communication path that allows the air chamber B in the speaker cabinet 41 to communicate with the external space. By adjusting the length of this communication path, the reproduced sound emitted from the speakers 8 and 9 into the air chamber B on the back side is appropriately phase-inverted and emitted to the front side.

  By providing such a duct 42, it is possible to effectively emit the reproduced sound in the low-frequency range, so that the bass characteristic can be improved. Further, by providing the speaker cabinet 41 with the duct 42 in common with both speakers, it is possible to reduce the manufacturing cost as compared to providing each speaker.

  In each of the first to third embodiments, the example in which the reproduction sound is output based on the input signal from the external sound source device has been described, but the present invention is not limited to this. For example, the stereo reproduction apparatus may include input signal generation means for generating an input signal based on audio signals composed of left and right channels.

  The input signal generation means performs an operation of adding a reverberation effect to the reproduced sound by generating an input signal with different phase characteristics. Specifically, the input signal generation means includes a delay circuit that delays the audio signal for each of the left and right channels and a superimposition circuit that superimposes the delayed delay signal on the original audio signal for each channel. It is conceivable that the later audio signal is output as an input signal to the driving unit of each speaker.

  Alternatively, the input signal generation unit may provide a delay time between the left and right channels for the audio signal, and output the audio signal with the phase delayed and the original audio signal as input signals to the driving units of the speakers, respectively. It is done. By performing different signal processing between the left and right channels in this way, it is possible to add reverberation effects such as echoes in the reproduced sound, so that the listener can listen to the reproduced sound with a richer sense of spread. .

It is the figure which showed an example of schematic structure of the stereo reproduction apparatus by Embodiment 1 of this invention. It is the figure which showed an example of the principal part detail in the stereo reproduction | regeneration apparatus of FIG. It is the figure which showed an example of the reproduction | regeneration operation | movement in the stereo reproduction | regeneration apparatus of FIG. 1, and the mode that the reproduction | regeneration sound by one speaker propagates to the listener P2 is shown. It is the figure which showed an example of the sound pressure level of the reproduction | regeneration sound emitted from a speaker, and the sound pressure level on the basis of the front direction of a speaker is shown for every propagation direction. It is the top view which showed the other structural example of the stereo reproduction apparatus by this Embodiment. It is the figure which showed the example of a structure of the stereo reproduction apparatus by Embodiment 2 of this invention. FIG. 7 is a perspective view showing a main part of the stereo reproduction device of FIG. 6, showing a state of reproduction sound reflecting means 21 composed of two reflecting plates 22 and 23. FIG. 7 is a diagram illustrating details of a main part in the stereo reproduction device of FIG. 6. It is the figure which showed the other structural example of the stereo reproduction apparatus by Embodiment 2 of this invention. It is the figure which showed the other structural example of the stereo reproduction apparatus by Embodiment 2 of this invention. It is the figure which showed the other structural example of the stereo reproduction apparatus by Embodiment 2 of this invention. It is the perspective view which showed the principal part in the stereo reproduction | regeneration apparatus of FIG. It is the perspective view which showed the other structural example of the stereo reproduction apparatus by Embodiment 2 of this invention. It is the front view which showed the structural example in the stereo reproduction apparatus by Embodiment 3 of this invention. It is the figure which showed the propagation path when a listener listens to the sound from a sound source. It is the figure which showed a mode that a listener listens to the reproduction sound by the conventional stereo reproduction apparatus.

Explanation of symbols

1, 20, 40 Stereo reproduction device 2, 41 Speaker cabinet 5, 6 Inclined surface 8, 9 Speaker 8a, 9a Vibrator 8b, 9b, 13 Drive unit 8c, 9c Open surface 10 Recess 11 Flat speaker 12 Diaphragm 21 Reproduced sound Reflecting means 22, 23 Reflecting plate 24 Apex portion 25-28, 31, 32 Reflecting plate 33 Crossing portion 34 End portion 35, 36 Reflecting plate 37 Through hole 42 Duct A1 Front axis A2 Direction angle B Air chamber

Claims (12)

Two speakers composed of a vibrating body having an opening surface for generating reproduced sound;
A stereo reproduction apparatus characterized in that each of the speakers is mounted with the opening surface facing the front side, and a box body arranged so that the front axes of the speakers intersect.   2. The speaker according to claim 1, wherein each of the speakers is arranged so that a part of a vibrating body in the other speaker is included in a directivity area having a predetermined sound pressure level in a reproduced sound from one speaker. Stereo playback device.   Each of the speakers has a conical diaphragm as a vibrating body, and is an inclined surface of the diaphragm in the other speaker in the directivity area of one speaker, and is on the opposite side to the one speaker. The stereo reproduction apparatus according to claim 2, wherein a part of the inclined surface is included.   2. The stereo reproduction apparatus according to claim 1, wherein each of the speakers is a flat speaker whose vibrating body is a flat diaphragm.   2. The stereo reproduction apparatus according to claim 1, further comprising reproduction sound reflecting means provided so as to protrude forward between the speakers in the box and reflecting the reproduction sound from the speakers to the speaker side.   6. The stereo reproduction apparatus according to claim 5, wherein the reproduction sound reflecting means is provided for each speaker and includes two reflection plates arranged with the reflection surface inclined toward the front side.   Each of the reflection plates is arranged so that a part of a reflection surface of the reflection plate corresponding to the speaker is included in a directivity area having a predetermined sound pressure level in a reproduced sound by the speaker. 6. The stereo reproduction device according to 6.   8. The stereo reproduction apparatus according to claim 7, wherein each of the reflectors is disposed such that a peak portion protruding forward is located on the near side of an intersection of the front axes of the speakers.   2. The stereo reproduction apparatus according to claim 1, further comprising two flat plates provided in the box and arranged to face each other so as to sandwich both speakers in parallel to the arrangement direction of the speakers.   The stereo reproduction apparatus according to claim 1, further comprising a duct provided in the box body and communicating an air chamber in the box body with an external space. Vibrator driving means for driving the vibrator in each of the speakers based on an input signal;
2. The stereo reproduction apparatus according to claim 1, further comprising input signal generation means for generating the input signal based on audio signals composed of left and right channels. 12. The stereo reproduction apparatus according to claim 11, wherein the input signal generation means generates an input signal by changing the phase characteristics of the left and right channels, and adds a reverberation effect to the reproduced sound.

Images