JPS62109412A - Acoustic reproducing device - Google Patents

Abstract

PURPOSE:To attain the similar effect of a conventional system even with two power amplifiers by actuating the 1st and 2nd power amplifiers as the BTL type power amplifiers to the low-frequency sounds. CONSTITUTION:The stereo signals are applied to input terminals 1A and 1B and the signals applied to the terminal 1B are applied directly to a power amplifier 4B. While the stereo signals applied to the terminal 1A undergo the 180 deg. phase inversion through an inverse amplifier 2 and are applied to a power amplifier 3A. These signals applied to both amplifiers 3A and 3B are amplifier up to a prescribed level of amplification to be sent to a speaker through the output terminals of both amplifiers 3A and 3B. The output signals of the amplifiers 3A and 3B are partially transmitted through the low frequency sound preventing capacitors 6A and 6B and drive the middle- and high-frequency sound speakers 4A and 4B respectively. Here the speaker 4A is connected to the amplifier 3A in the adverse way to the connection between the amplifier 3B and the speaker 4B so that the stereo effect is not deteriorated even with the inversion of phase caused by the amplifier 2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a 3D sound reproducing device comprising a speaker for reproducing medium and high sounds and a speaker for low sounds.

BACKGROUND OF THE INVENTION Conventionally, there is a 3D sound reproduction device which extracts bass sounds that do not impair the stereophonic sound from a stereo signal, adds signals from left and right channels, and reproduces the sound using dedicated speakers.

An example of the above-mentioned 3D type sound reproduction device will be described below with reference to FIG.

In FIG. 2, 11A and 11B are input terminals for stereo signals, 12B are high-pass filters that extract the middle and high frequencies of the stereo signal, 14k and 14B are power amplifiers that amplify the middle and high frequencies, and 16 are 16B are speakers that reproduce middle and high tones, respectively. Also, R1 and R2 have 11 input terminals.

A resistor for mixing stereo signals added to 11B, 13
15 is a power amplifier that amplifies the low frequency sound extracted by the low pass filter 13; 17 is a bass speaker.

The operation of the 3D sound reproduction apparatus shown in FIG. 2 will be explained.

Of the stereo signals applied to the input terminals 11A and 11B, medium and high frequencies of about 100H2 or higher are passed through the high-pass filter 12.
The signal passes through A and 12B, is amplified by 14 power amplifiers 14B, and is reproduced from 16 speakers 16B for medium and high frequency reproduction. Also, part of the signals applied to the input terminals 11 and 11B are mixed by resistors R1 and R2 to become a monaural signal. Of this monaural signal * 1ooHz
The low-pitched sounds below the level are extracted by the low-pass filter 13,
The signal is amplified by the power amplifier 16 and reproduced from the bass speaker 17.

Problems to be Solved by the Invention However, the 3D sound reproduction device with the configuration shown in Fig. 2 has the same problems as a normal two-channel stereo reproduction device.
There is a problem in that a power amplifier 16 must be added to amplify bass sounds.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a sound reproducing device that can obtain the same effects as a conventional 3D 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 the signal passed through the inverting amplifier, and a second input terminal. a second amplifier for amplifying the signal applied to the first and second amplifiers; a bass blocking capacitor connected between the output terminals of each of the first and second amplifiers and a speaker for medium and high frequency reproduction; a bass speaker connected between the output terminals of the second power amplifier; the bass speaker and the first bass speaker; It is composed of a low-pass filter composed of a coil and a capacitor provided between the output terminal of the second power amplifier and the output terminal of the second power amplifier.

Effect of the present invention With the above-described configuration, the first and second power amplifiers work as BTL type power amplifiers for bass sounds, and although there are two power amplifiers, they are different from the conventional type shown in the second example. You can get the same effect.

EXAMPLE Hereinafter, the sound reproducing apparatus of the present invention will be explained with reference to FIG.

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

In Fig. 1, IA and IB are stereo signal input terminals,
2 is an inverting amplifier that inverts the phase of the signal applied to one input terminal by 1800 degrees, 3 people, 3B are power amplifiers with the same characteristics, 4 people, aB are speakers for medium and high frequencies, 5 are speakers for bass sounds, 6 6B is a capacitor for blocking low frequency sounds, 7 is a coil, and 6C is a capacitor. The coil 7 and capacitor 6C constitute a low-pass filter.

Describe the operation of the sound reproduction device with the above configuration.0 Out of the stereo signals applied to the input terminal 1B, the signal applied to the input terminal 1B is directly transmitted to the power amplifier 4B.
added to. - The signal applied to one old human power terminal undergoes 180° phase inversion by inverting amplifier 2, and then is applied to three power amplifiers. The signals applied to the power amplifiers 3A, 3B are amplified to a preset amplitude and are applied to the speakers from the output terminals of the respective power amplifiers 3A, 3B. A part of the output signal of the power amplifiers 3 and 3B passes through the bass blocking capacitors 6 and 8B to drive the middle and high frequency speakers 4A and aB. Here, in order to prevent the four speakers from damaging the stereo effect due to phase inversion by the inverting amplifier 2, the connection with the three power amplifiers is reversed from the connection between the power amplifier 3B and the speaker 4B.

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

Generally, the phases of the bass sounds of a stereo signal of several hundred Hz or less are almost the same, so the sound reproduction apparatus of this embodiment described above uses the power amplifier 3A as previously learned.

3B will operate as a BTL type amplifier, and the bass sound will be the sum of two stereo input signals, 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, a power amplifier for low sound, which is indispensable in a conventional 3D system playback device, is not required, and an inexpensive 3D system sound playback device can be provided.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a 3D sound reproduction device according to an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional 3D sound reproduction device. 2...Inverting amplifier, 3 people, 3B...Inverting amplifier, 4 people, aB...Mid-high sound speaker, 6
・・・・・・Bass sub-h, 6A, aB, ac・
...Capacitor, 7...Coil. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (1)

[Claims] an inverting amplifier that inverts the phase of a signal applied to a first input terminal; and a first inverting amplifier that amplifies the signal that has passed through the inverting amplifier.
a second amplifier for amplifying a signal applied to a second input terminal; first and second capacitors connected to respective output terminals of the first and second amplifiers; 1
, a coil and a third capacitor connected in series between the output terminals of the first and second mid-high frequency speakers and the first and second amplifiers connected to the second capacitor; and the third capacitor. A sound reproduction device consisting of a bass speaker connected in parallel with a bass speaker.