JPH04262700A - Stereophonic sound reproducing device - Google Patents

Abstract

PURPOSE:To obtain a stereophonic sound reproducing device which has the extension of sound being naturally audible to a man. CONSTITUTION:Acoustic sources which are collected by a sound collecting mechanism restored based on the auditory organs of the man are provided at left and right and the acoustic sources are thrown against a wall from two directional speakers inside a sound place having the reflection wall in such a way that the sources do not mutually interfere. A listener listens the sound of the both speakers, which is reflected from the wall. This device can reproduce a deeper stereophony compared with a conventional stereophonic sound reproducing device.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional sound reproduction device used in a sound field where three-dimensional sound can be freely heard.

0002

[Background Art] When listening to stereophonic sound, two sources are usually used, which are picked up by left and right microphones located at a distance from the sound source and spaced apart from each other, or in the case of an orchestra, various musical instruments are used. A binary source is used in which signals from multiple microphone systems, each picking up the sounds of , are intentionally mixed. Then, in the playback sound field, the signals of the records and tape tracks based on the two sources as described above are each amplified by amplifiers, and the two amplified signals are placed in front of the sound field separated from each other on the left and right. A listener is positioned facing the opening of the speaker and directly listens to the sound waves emitted from the left and right speakers.

0003

[Problem to be Solved by the Invention] When listening to sound from speakers in such a reproduced sound field, a two-dimensional sensation can be obtained, but as is well known, the audible frequency range of the human ear is 10 in the low range. It is said that the frequency ranges from a few Hz to 20 KHz in the high range, and in real sound, the amount of sound components in a wide frequency range and various phases are mixed, so even in the reproduced sound field, it is said that the frequency range of the real sound can reach 20KHZ. If such a mixture is not performed, a good three-dimensional effect cannot be obtained from the human auditory experience.

[0004] If we consider the sound reproduced from a speaker, the wavelength of a low-frequency sound wave, for example 20Hz, within the above-mentioned audible frequency range is approximately 17m long, which is the sound speed of approximately 340m per second divided by 20Hz. If the diameter of the speaker used to reproduce this is 10 cm, this is a very small value compared to the wavelength of 17 m, which is 20 cm.
Since the HZ sound is similar to that emitted from a point-shaped sound source, it becomes a spherical wave from the point sound source, expands, and travels forward, as shown in FIG.

[0005] On the other hand, a high frequency sound wave of 20 KHZ has a wavelength of 1.7 cm, and when it is emitted from a speaker with a diameter of 10 cm, the diameter is large compared to the wavelength, so it becomes flat as shown in Fig. 7. It travels as a plane wave like the radiation from the diaphragm above.

[0006] As described above, the acoustic energy of the reproduced sound radiated into the air from the speaker has low frequency components spread out and radiated uniformly like a spherical wave from a point sound source, but as the frequency of the reproduced sound increases. Accordingly, it becomes a plane wave and the energy is concentrated on the sound axis of the speaker. Looking at the directivity characteristics of the speaker based on the increase in frequency, we can see that the sound pressure changes depending on the frequency in each direction on the speaker axis, 30° and 60°, and in the high range, the sound pressure changes after a certain frequency. (boundary frequency), which allows different frequency characteristics to be obtained.

The present invention has been made in view of the various characteristics of reproduced sound, and its purpose is to provide a system that provides a sufficient sense of three-dimensional sound by taking into consideration the source used as a sound source and the characteristics of reproduced sound. The object of the present invention is to provide a three-dimensional sound reproduction device that allows users to enjoy stereoscopic sound.

[0008]

[Means for Solving the Problems] In order to achieve the above-mentioned object, according to the present invention, two sources are amplified and supplied to separately separated left and right speaker boxes respectively, so that the reproduced sound produces a three-dimensional sound. A stereophonic sound reproduction device for listening to a stereophonic sound includes a sound field for reproducing two source sounds, and a stereophonic sound field disposed in the sound field.
two speaker boxes that reproduce the original source sound and radiate the sound in a direction where the two reproduced source sounds do not interfere with each other; and a reflective surface that reflects the sound emitted from the speaker box to the listener. and a sound source reproduction device that supplies left and right sound sources picked up by a sound pickup mechanism restored based on the human auditory organ to the two speaker boxes, respectively.

[0009]

Embodiments Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the external shape of a three-dimensional sound reproduction device according to the present invention.

In the figure, reference numeral 1 denotes an outer case, which is made of a dense wooden plank and connects the back sides of two boxes A and B each having one open side. The central portion is bent at a predetermined obtuse angle to form a symmetrical dogleg shape.

Reference numeral 11 indicates the open surface of box A, and 12 indicates the open surface of box B. Speakers, which will be described later, are housed inside these parts, and after being housed, there is a saran net through which sound waves can freely pass. A frame is attached to each open face.

[0013]The sound from the left and right speakers built into the outer casing 1 is configured to be cut off from each other by the center of the outer casing 1, and when listening to reproduced sound,
As shown in FIG. 2, the front part 13 of the outer casing 1 is installed facing the listener, and therefore the opening axes of the open surfaces 11 and 12 are arranged slightly rearward from the left-right line at the installation location.

Furthermore, in another embodiment of the present invention, the outer casing 1 serving as a sound source may be placed behind the listener 5.

FIG. 3 is a longitudinal cross-sectional view of an example of a speaker box built into the outer casing of this embodiment, FIG. 4 is a cross-sectional view thereof, both of which are cut including the speaker shaft, and FIG. 5 is a view of the speaker box. FIG.

In these drawings, reference numeral 2 denotes a speaker box, which is made of a dense plate material, houses a full-range speaker 3, and efficiently radiates the reproduced sound to the outside. It is formed into a so-called bass reflex type cabinet, which has a sound path W for the low range.

[0017] Then, the baffle plate 2 inside the speaker box 2
Upper and lower plates 22, 23 forming a sound path T and plates 24, 25 spread forward are attached to 1, so that sound waves in the high and middle range are horizontally expanded and radiated. It is formed. Further, a plate member 26 that extends rearward is attached below the baffle plate 21, and guides low-frequency sound waves emitted from the back surface of the speaker 3, extends its passage path, and inverts the phase. opening 2
The sound waves are emitted from the front of the speaker 3, and the sound waves in the low frequency range are reinforced together with the sound waves from the front of the speaker 3. In addition,
Reference numeral 28 denotes a bolt hole, in which a predetermined bolt is used to fix the speaker box 2 when it is housed in the aforementioned outer casing 1, and when it is housed, two speaker boxes 2 with the same acoustic characteristics are fixed. The left and right open surfaces 11 of the outer casing 1 are used, respectively.
The speaker boxes 2 are fixed so that the sound paths T and W of each speaker box 2 are opened corresponding to the numbers 12 and 12.

FIG. 2 is a diagram showing the arrangement of the outer casing and the radiation state of sound waves when listening to stereophonic sound in this embodiment. Next, the operation of this embodiment will be explained using this diagram.

First, as shown in FIG. 2, an outer casing 1 housing speaker boxes 2, 2 on the left and right is installed in front of the listener 5 so that the front portions 13 thereof face each other.

[0020] The speakers 3, 3 of the left and right speaker boxes 2, 2 are supplied with an acoustic signal for driving them, and the acoustic signal used is one obtained by amplifying the following source to a predetermined value.

[0021] Here, the sources used for the left and right speakers 3, 3 are, for example, those recorded on a record or two separate tracks, and the sound is recorded from the auricle, external auditory canal, and auditory canal of the human auditory organ. Using a sound recording mechanism called a so-called dummy head, which is faithfully imitated and restored,
It uses signals from the left and right microphones placed at positions corresponding to the eardrum.

[0022] When signals obtained by amplifying such acoustic sources are supplied to the speakers 3, 3, they are radiated from the open surfaces 11, 12 toward the left and right walls, respectively.

The sounds radiated left and right from the speaker box 2 proceed through the reproduction sound field without interfering with each other.

Here, for example, high-frequency sound waves on the speaker axis emitted from the left open surface 11 are reflected by the left wall surface 41 and the rear wall surface 42 and reach the listener 5. Also,
Sound waves from the speaker 3, which are slightly lower than the above-mentioned high-frequency sound waves, move slightly away from the axis and proceed to the wall surface 41, rear wall surface 42, etc. As a result, the left side of the reproduction sound field 4 is filled with the acoustic energy of these reflections and diffused reflections, and the listener 5's left ear hears a complex mixture of the left speaker and the left side of the reproduction sound field 4. You will hear the acoustic energy of 3.

On the other hand, the sound reproduced from the right speaker is a complex mixture of mid- and high-range sound waves with different axial strengths depending on the frequency and low-range sound waves radiated as spherical waves.
This fills the playback sound field 4, especially on the right side, and listens to the listener 5.
By listening to these complexly mixed acoustic energies from the left or right speaker with the left or right ear, respectively, a three-dimensional sound sensation can be obtained.

Although the present invention has been explained above with reference to the above-mentioned embodiments, various modifications and applications are possible within the scope of the gist of the present invention, and these modifications and applications are not excluded from the scope of the present invention. do not have.

[0027]

Effects of the Invention According to the present invention, as explained using the above-mentioned embodiments, left and right sounds recorded using a sound recording mechanism restored based on the human auditory organ can be used as a sound source. A source is used, and the source is amplified and supplied to the left and right speaker boxes whose sound axes are tilted slightly behind the left and right lines in front of the listener, and the sound waves are radiated into the playback sound field.
The left and right acoustic energy, which is reflected off the walls of the playback sound field and mixed in a complicated manner, is heard by the listener's left and right ears, respectively, resulting in a more pleasant three-dimensional sound experience than the human auditory experience. It will be done.

Further, according to the present invention, since the left and right speaker boxes are each of a bass reflex type, there is an advantage that the bass reproduction band is widened and efficient reproduction sound can be obtained even with a small volume speaker box.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of the external shape of a three-dimensional sound reproduction device according to the present invention.

FIG. 2 is an explanatory diagram when listening to stereophonic sound in this embodiment.

FIG. 3 is a longitudinal sectional view of an example of a speaker box used in this embodiment.

FIG. 4 is a cross-sectional view of an example of a speaker box used in this embodiment.

FIG. 5 is a front view of an example of a speaker box used in this embodiment.

FIG. 6 is an explanatory diagram of a spherical wave from a point sound source.

FIG. 7 is an explanatory diagram of a plane wave from a diaphragm.

[Explanation of symbols]

1...Outer casing 2...Speaker box 3...Speaker 4...Reproduction sound field 5...listener 11, 12...Open surface T, W…Ondou

Claims (3)

[Claims] Claim 1: A stereophonic sound reproduction device that amplifies two source sounds and supplies them to separately separated left and right speaker boxes so that three-dimensional sound can be heard from the reproduced sound. a field, two speaker boxes arranged in the sound field, which reproduce the two source sounds and radiate the sound in a direction in which the two reproduced source sounds do not interfere with each other; and a sound source reproduction device that supplies left and right sound sources picked up by a sound pick-up mechanism restored based on the human auditory organ to the two speaker boxes, respectively. 3D sound reproduction device. [Claim 2] An outer casing formed in a dogleg shape having left and right end portions that are open and a center portion that blocks sound and is bent at an obtuse angle is used, and the left and right speakers are connected to each other. A three-dimensional sound reproducing device characterized in that each speaker is housed so that the sound reproduced from the box is radiated from both ends of the outer casing. 3. The left and right speaker boxes are bass reflex type speaker boxes having a sound path for medium and high ranges and a sound path for low ranges that inverts the phase of sound in the low range. The three-dimensional sound reproduction device according to claim 1 or claim 2.