JP2688839B2 - Audio output device - Google Patents

Description

The present invention relates to an audio output device suitable for application to a system capable of reproducing a high fidelity stereophonic sound field (hereinafter referred to as hi-fi stereo). is there.

[Prior Art] Conventionally, the ideal listening point in high-fidelity stereo is the apex of an isosceles triangle having two speakers as the bases, and listening at this position provides the best sense of presence and high fidelity. Has been

As described above, the reason why the optimum listening range is limited is mainly that the directivity distribution of the acoustic energy in the audio output unit is not controlled. For this reason, an audio system technology for enjoying a true high-fidelity stereo feeling in a wide range has not been established.

However, in recent years, an audio output device using an audio mirror has been proposed as a technique that enables directivity distribution control over a wide band, as shown in, for example, Japanese Patent Application No. 61-75144. In this device, an acoustic reflector that determines the output directivity in the vertical direction is arranged facing the diaphragm of the speaker, and the directivity distribution of the high-quality speaker is obtained by the acoustic reflector to obtain an omnidirectional virtual sound source. To do.

5 to 7 are a front view, a side view and a plan view showing the main configuration of a conventional audio output device capable of controlling directivity distribution.

A woofer (low temperature speaker) 2 is attached to the front surface of a sealed cylindrical speaker cabinet 1, and a squawker (middle-tone speaker) 3 is attached to the front side of the upper surface in an upward direction. Further, on the upper surface of the speaker cabinet 1, a conical acoustic reflector 5 for middle sound is installed via a plurality of support members 4.

Further, a plurality of support members 6 are provided upright on the upper portion of the acoustic reflector 5 for middle sound, and a conical acoustic reflector 7 for high sound is installed while being supported by the support members 6. A tweeter (treble speaker) 8 is installed above the middle-tone acoustic reflector 5 so that sound waves are generated toward the side surface of the high-tone acoustic reflector 7. Further, a squawker 3 is installed above the speaker cabinet 1 so that sound waves are generated toward the side surface of the middle-tone acoustic reflector 5.

When driving the woofer 2, the squawker 3, and the tweeter 8, a dedicated amplifier for amplifying the frequency band matched to each reproduction frequency region is individually connected, or a single amplifier is used for low, middle, and high frequencies. A method is used in which each speaker is driven through a divider that separates each frequency.

Next, the operation of the audio output device having the above configuration will be described.

This audio output device is installed so that the front of the woofer 2 faces the listener. The frequency range shared by the woofer 2 is a low temperature of several hundreds Hertz or less and has no directivity. Therefore, its acoustic energy is directly output toward the listening point. Further, since it does not have directivity, it is not necessary to provide a reflector or the like on the woofer 2.

On the other hand, the acoustic energy obtained by the tweeter 8 and the squawker 3 is reflected by the side surfaces of the high-pitched acoustic reflector 7 and the mid-tone acoustic reflector 5, respectively, and radiated toward the listener. As is well known, since the acoustic energy of the frequencies in the middle and high frequencies has a directivity, by using the acoustic reflector 5 for middle sound and the acoustic reflector 7 for high sound, the sound waves reflected by these are The sound reflector 5 for sound and the sound reflector 7 for treble are scattered in the circumferential direction. Therefore, the reflected sound is not concentrated in one place, and the virtual sound source is formed in a wide range.

[Problems to be Solved by the Invention] However, in the conventional audio output device as described above, although good localization is obtained at the listening point 81 as shown in FIG. 8, two points such as the listening points 82 and 83 are obtained. If the location deviates from the inside of the chain line, the localization becomes poor and it cannot be an ideal listening point.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an audio output device capable of expanding the range of listening points.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an audio output device including a speaker and an acoustic reflector that reflects a sound wave emitted from the speaker toward a listening point. Therefore, the acoustic reflector has an elliptic cone shape.

[Operation] By considering the acoustic energy reflected from the acoustic reflector by configuring as described above, a wide and flat sound pressure distribution level can be obtained in the direction orthogonal to the longitudinal direction of the elliptical cone of the acoustic reflector. To be
Expands the area of optimal listening points.

[Embodiment] FIGS. 1 to 3 are a front view, a side view and a plan view showing the main structure of an embodiment of the present invention. In the present embodiment, the same reference numerals are used for those having the same or the same functions as those shown in FIGS. 5 to 7, and therefore, redundant description will be omitted below.

The present embodiment is different from the conventional configuration in that instead of the middle-tone acoustic reflector 5 and the high-tone acoustic reflector 7 shown in FIGS. 5 to 7, the conical and elliptical middle-tone acoustic reflector is used. Body 10
And the treble acoustic reflector 11 is used.

Elliptical medium sound reflector 10 and treble sound reflector 11
Is arranged such that the longitudinal direction of the ellipse is aligned with the listening point direction and the squawker 3 and the tweeter 8 are located slightly closer to the listening point than the center thereof.

With the above configuration, the reflected sound in the mid-range and high-range by the acoustic reflector 10 for mid-tone and the acoustic reflector 11 for high-pitched sound, since the reflector has an elliptical shape, the acoustic energy reflected by its short width surface. And the acoustic energy reflected by the long width surface is different. That is, as shown in FIG. 4, the sound pressure level distribution in the direction orthogonal to the longitudinal direction of the elliptical middle-tone acoustic reflector 10 and treble acoustic reflector 11 becomes large. This allows
Left and right listening points 41 and 43 of the central listening point 42 are covered by the sound pressure distribution of the left and right speaker systems, expanding the listening point area where the best high fidelity and high three-dimensional sound field reproduction can be obtained. can do.

[Effects of the Invention] As described above, according to the present invention, the acoustic reflector has an elliptical cone shape, so that the region of the optimum listening point can be expanded.

[Brief description of the drawings]

1 to 3 are a front view, a side view and a plan view showing a main structure of an embodiment of the present invention, FIG. 4 is a characteristic diagram showing a directional characteristic according to the embodiment of the present invention, and FIGS. FIG. 7 is a front view, a side view and a plan view showing the main configuration of a conventional audio output device, and FIG. 8 is a characteristic diagram showing the directional characteristics of the conventional audio output device. In the figure. 1: Speaker cabinet 2: Woofer 3: Squawker 4,6: Support member 8: Tweeter 10: Acoustic reflector for midrange sound 11: Acoustic reflector for high range sound

Claims (1)

(57) [Claims] 1. An audio output device comprising a speaker and an acoustic reflector for reflecting a sound wave emitted from the speaker toward a listening point, wherein the acoustic reflector has an elliptical cone shape. Characteristic audio output device.