JPH0787318B2 - Sound reproduction device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a 3D-type sound reproducing device including a speaker for reproducing middle and high frequencies and a speaker for low temperature.

2. Description of the Related Art Conventionally, there is a 3D sound reproduction device as a method of extracting a bass sound that does not impair the sense of stereo from the stereo signal, adding the signals of both left and right channels, and reproducing them by a dedicated speaker.

An example of the 3D type sound reproducing device will be described below with reference to FIG.

In FIG. 2, 11A and 11B are input terminals for stereo signals, 12A and 12B are high-pass filters for extracting the middle and high tones of the stereo signals, 14A and 14B are power amplifiers for amplifying the middle and high tones, and 16A and 16B are These are speakers that reproduce high and medium tones, respectively. In addition, R1 and R2 are resistors for mixing the stereo signals applied to the input terminals 11A and 11B, 13 is a low-pass filter that takes out low frequencies from the mixed signals, and 15 is a power amplifier that is taken out by the low-pass filter 13. Amplify the bass. Reference numeral 17 is a bass speaker.

The operation of the 3D system sound reproducing apparatus shown in FIG. 2 will be described.

Of the stereo signals applied to the input terminals 11A and 11B, 100Hz
Mid-high frequencies above a certain level pass through the high-pass filters 12A and 12B,
Loudspeaker for mid-high range reproduction amplified by power amplifiers 14A and 14B 1
Played from 6A, 16B. Further, a part of the signals applied to the input terminals 11A and 11B are mixed by the resistors R1 and R2 to become a monaural signal. Of this monaural signal, low frequencies of about 100 Hz or less are extracted by the low-pass filter 13, amplified by the power amplifier 15, and reproduced from the low-frequency speaker 17.

Problems to be Solved by the Invention However, in the 3D sound reproducing apparatus having the structure as shown in FIG. 2, a power amplifier 15 for amplifying bass must be added to a normal 2-channel stereo reproducing apparatus. There was a problem.

In order to solve the above problems, the present invention is to provide a sound reproducing device that can obtain the same effect as the conventional 3D system sound reproducing device without using a bass power amplifier.

Means for Solving the Problems The present invention provides an inverting amplifier that inverts the phase of a signal applied to a first input terminal, a first amplifier that amplifies a signal that has passed through the inverting amplifier, and a second amplifier. A second amplifier for amplifying a signal applied to an input terminal; first and second capacitors each having one end connected to an output terminal of each of the first and second amplifiers; A first and a second mid-high range speaker connected to the other end of the second capacitor;
A coil and a third capacitor connected in series between the output terminals of the first and second amplifiers, and a bass speaker connected in parallel with the third capacitor.

Operation The present invention has the above-mentioned configuration, and the first and second power amplifiers work as BTL system power amplifiers for low sounds, and the same power supply system as the second conventional system even though there are two power amplifiers. You can get the effect.

EXAMPLE An audio reproducing apparatus of the present invention will be described below with reference to FIG.

FIG. 1 is a block diagram of a sound reproducing device according to an embodiment of the present invention.

In FIG. 1, 1A and 1B are stereo signal input terminals, 2 is an inverting amplifier that inverts the phase of the signal applied to the input terminal 1A by 180 °, 3A and 3B are power amplifiers having the same characteristics, and 4A and 4B.
Is a speaker for middle and high frequencies, 5 is a speaker for bass, 6A and 6B are capacitors for blocking bass, 7 is a coil, 6C is a capacitor, and the coil 7 and the capacitor 6C constitute a low-pass filter.

The operation of the sound reproducing device having the above configuration will be described.

Of the stereo signals applied to the input terminals 1A and 1B, the signal applied to the input terminal 1B is applied to the power amplifier 4B as it is. On the other hand, the signal applied to the input terminal 1A is the inverting amplifier 2
After 180 ° phase inversion by, it is added to the power amplifier 3A. The signals applied to the power amplifiers 3A and 3B are amplified to a preset amplitude and
It is added to the speaker from the output terminals of A and 3B. Power amplifier
Part of the output signals of 3A and 3B passes through the bass blocking capacitors 6A and 6B to drive the mid-to-high range speakers 4A and 4B. Here, the speaker 4A is connected to the power amplifier 3A in the opposite manner to the connection between the power amplifier 3B and the speaker 4B in order to prevent the stereo effect from being damaged by the phase inversion by the inverting amplifier 2.

Further, another part of the output signals of the power amplifiers 3A and 3B passes through a low pass filter composed of the coil 7 and the capacitor 6C to drive the bass speaker 5.

Here, generally, the phase of the low-pitched sound of a stereo signal of several hundred Hz or less is almost the same phase, so in the low-pitched sound reproducing apparatus, the power amplifiers 3A and 3B operate as a BTL type amplifier, The bass sound is a combination of two input signals of a stereo signal, and the same effect as the conventional example shown in FIG. 2 can be obtained.

EFFECTS OF THE INVENTION As described above, according to the present invention, it is possible to provide an inexpensive 3D system sound reproduction device capable of reproducing so-called heavy bass, without the need for a power amplifier dedicated to bass, which is indispensable in the conventional 3D system reproduction device.

[Brief description of drawings]

FIG. 1 is a block diagram of a 3D system sound reproducing device according to an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional 3D system sound reproducing device. 2 ... Inverting amplifier, 3A, 3B ... Inverting amplifier, 4A, 4B ... Mid-high range speaker, 5 ... Bass speaker, 6A, 6B, 6C ... Capacitor, 7 ... Coil.

Claims (1)

[Claims] 1. An inverting amplifier for inverting the phase of a signal applied to a first input terminal, a first amplifier for amplifying a signal passed through the inverting amplifier, and a signal applied to a second input terminal. A second amplifier for amplifying the first and second capacitors, first and second capacitors each having one end connected to each output terminal of the first and second amplifiers, and the other ends of the first and second capacitors First and second mid-high range speakers connected to each other, a coil and a third capacitor connected in series between the output terminals of the first and second amplifiers, and the third capacitor in parallel. A sound reproducing device including a connected bass speaker.