JPH06105997B2 - Speaker system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a speaker system having bidirectionality.

2. Description of the Related Art In recent years, improvements in video image technology have made it possible to show movies on a large screen at home. Accompanied by this, audio equipment has also been required to have the power and sound quality suitable for a large screen. From such a background, as shown in FIG. 4, the audio device combined with the home video reproducing device 12 has two or three speaker systems 7 in front of the viewer 9 and two or more speaker systems 7 in the side or the rear. It is often a so-called surround sound field reproducing device using the above speaker system 10.

The front channel of this surround sound field playback device produces signals such as soft voice and background music to be played back, and the rear channel produces indirect sound and reverberation by combining the front channel signal using a special processing device. We deal with related signals. The speaker system for each channel is basically required to have the performance corresponding to the signal to be handled. However, if the timbre of the direct sound component coming from the front and the timbre of the indirect sound or the reverberant component coming from the back are different, the viewer feels strange It is desirable that the front and rear speaker systems have the same type as much as possible.

Since the rear channel handles indirect sound, it is desirable to install a speaker system so that the sound from the speaker system does not reach the viewer directly and the sound image is not localized in order to improve a good surround effect. As shown in FIG. 4, there is a method in which a large number of rear speaker systems 10 are used to surround a viewer so as to disperse sound sources and enhance the above-mentioned effect. However, on the other hand, it is required to obtain the maximum effect with a small number as much as possible from the viewpoint of installation site problems and cost.

From the above points, a speaker system as shown in the sectional view of FIG. 5 has been proposed as a rear speaker system. In FIG. 5, 1 and 2 are speaker units having the same performance, 3 is a cabinet, and the speaker units 1 and 2 are electrically connected so as to operate in opposite phases. FIG. 6 is a sound pressure frequency characteristic in front of the speaker unit 1 or the speaker unit 2 of the speaker system shown in the sectional view of FIG. 5, and FIG. 7 is a speaker in the speaker system shown in the sectional view of FIG. The front side of the speaker unit 1 in the band equal to or higher than the frequency at which the equivalent distance between the sound sources of the units 1 and 2 becomes a half wavelength is set to 0.
゜, an example of polar coordinate directional characteristics when the front side of the speaker unit 2 is set to 180 °, and the sound pressure is maximum at the front of the speaker units 1 and 2 and at a position equidistant from the speaker units 1 and 2, that is, the cabinet side. It shows bidirectionality that minimizes sound pressure.

FIG. 8 is a domestic video reproducing apparatus using the speaker system shown in the sectional view of FIG. 5 as a rear speaker system.
This is an example of an audio device combined with the speaker system 12. However, when the speaker system is installed as shown in this figure, the directional characteristics of the rear speaker system 11 are bidirectional as shown in FIG. Thus, the sound pressure is minimized and the sound of the rear speaker system 11 does not reach the viewer 9 directly, and a good surround effect can be given to the viewer 9 while using a small number.

However, in the speaker system shown in FIG. 5, as shown in FIG. 6, the sound pressure of the speaker units 1 and 2 is less than the frequency f _{c at} which the equivalent distance between the sound sources of the speaker units 1 and 2 becomes a half wavelength. Since they cancel each other out and cause a sudden drop in sound pressure level, if you want to reproduce in the low frequency range, make the cabinet larger and make speaker units 1, 2
In this case, the equivalent distance between the sound sources is increased to lower the frequency at which cancellation occurs, or a large level correction is required on the amplifier side that drives the speaker system, which causes a serious problem in practical use.

In view of the above problems, the present invention provides a speaker system that can provide a good surround effect to a viewer while using a small number of speakers and that does not cause a sudden decrease in sound pressure level in a low frequency range.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention is to install speaker units having the same performance on both one baffle plate of a cabinet and a baffle plate facing each other, and one speaker unit has both speaker units. the frequency f _c with twice the equivalent distance between the sound source units at a wavelength connects a high-pass filter having a cut-off, and both the speaker units are connected to electrically to operate in opposite phases structure It is due to.

Effect The present invention can give a good surround effect to a viewer while using a small number of devices by the above-mentioned configuration, and does not cause a sudden decrease in sound pressure level in a low frequency range.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, a speaker unit 1 having the same performance,
2 are attached to one baffle plate 5 facing the one baffle plate 4 of the cabinet 3, respectively. In addition, a high-pass filter 6 that cuts off a frequency having a wavelength that is twice the shortest distance between the speaker units 1 and 2 is connected to the speaker unit 1, and the speaker units 1 and 2 are opposite to each other. Electrically connected to operate in phase.

For equivalent distance between the sound source of the speaker unit 1 in the above structure is in the band of frequencies higher than the frequency f _c to be a half wavelength, the sound emitted from the speaker unit 1 is the same amplitude opposite phase characteristics, the speaker unit 1 , 2 shows the directivity where the sound pressure is maximum, and the sound pressure is minimum at the positions equidistant from the speaker units 1 and 2, that is, at the sides of the cabinet. On the other hand, in the low frequency range, since the speaker unit 1 limits the input signal of frequency f _c or less by the high-pass filter 6, only the speaker unit 1 is driven in FIG. On the front surface of the speaker unit 1 at the time of performing, the sound pressure frequency characteristic of FIG. 2b is shown. Therefore, since the speaker unit 1 and the speaker unit 2 have opposite phases but different amplitude levels, the cancellation of the sound pressure is alleviated, and the sudden decrease of the sound pressure level as in the speaker system shown in the cross-sectional view of FIG. 5 is prevented. it can. FIG. 2c is a sound pressure frequency characteristic in the front of the speaker unit 1 when both the speaker unit 1 and the speaker unit 2 are driven in the speaker system according to this configuration.

In the embodiment, the speaker units 1 having the same performance are
2 is used, but it is also effective to use a multi-way speaker system composed of a speaker unit and a dividing network having the same performance, and connect the above high-pass filter to one of the multi-way speaker systems. Needless to say.

FIG. 3 is a layout diagram showing an example of the audio device according to the present invention shown in correspondence with the conventional example of FIG. 8. The speaker system of the present embodiment is used as a rear speaker system 8 of the audio device, and a viewer 9 is provided. This is an example of a case where they are arranged on both sides of. The rear speaker system 8 does not cause a sudden decrease in the sound pressure level in the low frequency range, so that a better surround effect than the conventional example can be obtained.

As described above, according to the present invention, speaker units having the same performance are attached to both one baffle plate and the opposite baffle plate of a cabinet, and one speaker unit has an equivalent sound source between the speaker units. A high-pass filter that cuts off a frequency having a wavelength that is twice the distance is connected, and both speaker units are electrically connected so that they operate in opposite phases. It is possible to realize a speaker system which can provide a good surround effect and which does not cause a sudden drop in sound pressure level in the low frequency range.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a speaker system according to an embodiment of the present invention, FIG. 2 is a sound pressure frequency characteristic diagram of the speaker system, and FIG. 3 is a home video reproduction using the speaker system as a rear speaker system. FIG. 4 is a layout view showing an example of an audio device combined with the device, FIG. 4 is a layout view showing an example of the audio device combined with a home video reproducing device using a conventional speaker system as a rear speaker system, and FIG. FIG. 6 is a cross-sectional view of a conventional bidirectional speaker system, FIG. 6 is a sound pressure frequency characteristic diagram of the conventional speaker system, FIG. 7 is a polar coordinate directivity characteristic diagram of the speaker system, and FIG. 8 is a conventional speaker system. FIG. 6 is a layout view showing an example of an audio device combined with a home video reproducing device using the as a rear speaker system. 1,2 …… Speaker unit, 3 …… Cabinet, 4,5…
... Baffle plate, 6 ... High-pass filter, 7 ... Front speaker system, 8 ... Rear speaker system, 9 ...
… Viewer, 12 …… Video equipment, 13 …… Input terminal, 14a-14d
...... Internal wiring material.

Claims (1)

[Claims] 1. A speaker unit having the same performance is mounted on both one baffle plate and a baffle plate facing each other in a cabinet, and one of the speaker units has a wavelength that is twice the equivalent distance between the sound sources of both speaker units. A speaker system characterized in that a high-pass filter that cuts off the frequency that it has is connected, and that both speaker units are electrically connected so that they operate in opposite phases.