JPH0660532B2 - Sound reproduction room - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound reproduction room suitable for listening to heavy bass reproduction.

2. Description of the Related Art In recent years, the quality of music signals has been significantly improved with the progress of digital technology.

In particular, there is a strong demand for improving the performance of the sound reproduction system as the quality of heavy bass reproduction is improved.

Hereinafter, the conventional sound reproduction as described above will be described with reference to the drawings. FIG. 6 shows the structure of a conventional sound reproduction chamber. In FIG. 6, 14 is a conventional sound reproduction room, 15 and 16 are right and left speaker systems, and 4 is a listener. Sound reproduction room 14 for sound reproduction
Is composed of a finite number of flat wall surfaces based on a rectangular parallelepiped, and the reproduction speaker systems 15 and 16 use a closed box type or bass reflex type cabinet or a speaker system having a horn type incorporated in the speaker system itself. Was playing sound.

Fig. 7 shows the transmission characteristics between two points in a rectangular parallelepiped reproduction room (4.8 x 7.7 x 28 m), and it can be seen that a clear resonance occurs in the low frequency range (building acoustics , P
31, Junichi Maekawa, Kyoritsu Publishing).

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in such a conventional example, first of all, a specific frequency is emphasized or attenuated due to the natural vibration of the reproduction chamber, so that the listener can obtain a uniform frequency and listening position. There was a problem that it could not be transmitted.

Secondly, in the conventional speaker system, since the diaphragm area of the speaker system, especially the woofer of the speaker system is small compared to the size of the reproduction room, the low-frequency sound conversion efficiency is poor, and the speaker system is driven by a high-power power amplifier. However, it was difficult to obtain a low-range sound pressure that would be heard by the listener. Even when the horn-type speaker system is used, it is difficult to obtain the above-mentioned low tone because the acoustic contact between the horn and the reproduction room is poor.

In view of the above problems, the present invention provides a sound reproduction room capable of performing uniform transmission of frequency and listening position to a listener in a low frequency range with high acoustic conversion efficiency.

Means for Solving the Problems In order to achieve this object, the sound reproduction chamber of the present invention has a wall surface having a spherical shape and an acoustic wall having an opening in the wall surface and continuously coupled to the wall surface shape. The sound and driver unit are installed at the entrance of the acoustic tube.

Action Due to the spherical wall shape of this configuration, it becomes difficult for resonance at a specific frequency due to natural vibration of the low range of the sound reproduction room to occur,
Therefore, it is possible to transmit a uniform sound to the listener. In addition, the acoustic tube smoothly connected to the wall surface spreads the sound waves smoothly into the acoustic reproduction chamber, so that the acoustic conversion efficiency can be increased, and the opening area of the acoustic tube can be increased according to the size of the acoustic reproduction chamber. By taking this, it is possible to obtain the sound pressure of the low tone that the listener feels.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic side sectional view of the structure of a sound reproducing chamber in one embodiment of the present invention. In FIG. 1, 1
Is a sound reproduction chamber having a spherical wall surface, 2 is an acoustic tube having an opening in the wall surface, and continuously connected to the wall shape,
3 is a driver unit provided at the entrance of the acoustic tube 2,
4 is a listener and 5 is an acoustic tube opening.

The operation of the sound reproducing room configured as above will be described.

First, assuming that the inner diameter of the wall surface of the sound reproduction chamber 1 is L [m], this L becomes a half wavelength b [Hz] (b = C / 2
At frequencies below (L, C: speed of sound), standing waves and resonance phenomena due to natural vibration do not occur. Therefore, the listener 4 receives a uniform sound pressure at frequencies below b. For example, when L = 1.5 m, b = 113.3 [Hz], and a uniform sound pressure distribution can be obtained in a band below about 100 [Hz].

Next, the acoustic tube 2 is in continuous or smooth contact with the wall surface of the sound reproducing chamber 1, and the wavefront of the sound wave radiated from the driver unit 3 gradually spreads to the sound reproducing chamber 1. The sound output of 3 can be efficiently transmitted to the listener 4.

Furthermore, by increasing the area of the acoustic tube opening 5, the sound reproduction chamber 1 is subjected to the Stiff Nef control in the same manner as when listening to headphones, and the transmission characteristic of the acoustic output of the driver unit 3 is expanded to the DC region. Can
It is possible to obtain the low-frequency reproduction capability that the listener 4 can experience.

The acoustic transmission characteristics of the first embodiment thus obtained are shown in FIG. As shown in this figure, 20 to 100 [H
It is possible to obtain uniform and flat excellent transmission characteristics over z].

Next, a second embodiment will be described. FIG. 3 is a schematic sectional view showing the structure of the second embodiment. In FIG.
Reference numerals 6 and 7 are right and left channel acoustic tubes, 8 and 9 are right and left channel driver units, and 10 and 11 are right and left acoustic tube openings.

This second embodiment is an extension of the first embodiment to two channels, and in recent digital recording, it becomes easy to move the sound image to the left and right even in the low frequency range.
This has the effect of compensating for the drawback of degrading the resolution in the low range of the system. Other effects are similar to those of the first embodiment.

Next, a third embodiment will be described. FIG. 4 is a schematic side sectional view showing the structure of the embodiment shown in FIG.

In FIG. 4, 12 is an acoustic tube having a constant cross-sectional area. The same effect as that of the first embodiment can be obtained in the frequency band below the frequency that causes resonance in the length of the acoustic tube 1.
There is an effect that the shape of 2 can be simplified.

Next, a fourth embodiment will be described. FIG. 5 is a schematic side view showing the structure of the fourth embodiment. In FIG.
Reference numeral 13 is an acoustic tube having a constant cross-sectional area, and part of the structure of the acoustic tube 13 can also be used as the structure of the wall surface of the sound reproducing chamber 1, so that there is an effect that the entire structure can be simplified. The thickness of the walls of each of the above sound reproduction chambers is omitted in the drawing.

EFFECTS OF THE INVENTION As described above, according to the present invention, by providing the wall surface having a spherical shape, resonance of a specific frequency due to natural vibration in the low frequency range of the sound reproduction chamber is unlikely to occur, and therefore a uniform sound is heard to the listener. Is possible, and since the sound wave is smoothly spread to the sound reproduction chamber by the sound tube continuously coupled to the wall surface, the sound conversion efficiency can be increased,
Further, by making the opening area of the acoustic tube large, it is possible to realize an excellent acoustic reproduction room capable of obtaining a number of effects that a low-pitched sound pressure that a listener can experience can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view showing the structure in the first embodiment of the present invention, FIG. 2 is a transmission characteristic diagram of a listening room in the first embodiment, and FIG. 3 is a second embodiment of the present invention. FIG. 4 is a schematic sectional view showing a structure in an example, FIG. 4 is a schematic sectional view showing a structure in a third embodiment of the present invention, and FIG. 5 is a schematic sectional view showing a structure in a fourth embodiment of the present invention. 6A and 6B are a schematic top view and a schematic side view of a sound reproducing chamber in the conventional example, and FIG. 7 is a transmission characteristic diagram of the conventional sound reproducing chamber. 1 ... Wall of reproduction room, 2 ... Sound tube, 3 ... Driver unit, 4 ... Listener, 5 ... Sound tube opening.

Claims (4)

[Claims] 1. A wall surface having a spherical shape, an acoustic tube having an opening in the wall surface and continuously coupled to the wall surface shape, and a driver unit at an entrance of the acoustic tube. Sound reproduction room. 2. The sound reproducing chamber according to claim 1, wherein the acoustic shape is a horn shape in which the cross-sectional area of the acoustic tube increases as it goes to the opening. 3. The sound reproducing chamber according to claim 1, wherein the acoustic tube has a constant cross-sectional area. 4. The sound reproducing chamber according to claim 1, wherein a part of the structure of the wall surface of the acoustic tube also serves as a part of the wall structure of the sound reproducing chamber.