JPH062393Y2 - Loudspeaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the invention: [Industrial field of application] The present invention relates to a loudspeaker, and is particularly used in the field of expanding and enhancing a low frequency range.

[Prior Art] FIG. 2 is a block diagram of a bass range expansion type loudspeaker used in the field of audio. This loudspeaker is a loudspeaker that connects an amplifier 1 equipped with a SEPP-OTL system circuit and a speaker system 3, and further has two loudspeakers.
Driving the pair of SEPP-OTL circuits 2a and 2b in reverse phase,
The bass range is expanded by adding a so-called BTL circuit type loudspeaker system in which the bass speaker system 4 is connected between the respective output points.

[Problems to be Solved by the Invention] Such a conventional bass range expansion type loudspeaker device can measure the bass range, but requires two amplifiers 1 and 2 and, from a different viewpoint, Three SEPP-OTL circuit type amplifiers (1, 2a, 2b) are required, which is expensive.

The present invention has been made in view of the above points, and was made as an attempt to provide a loudspeaker capable of expanding and enhancing the low frequency range at low cost.

Configuration of the Invention: As shown in the block diagram of FIG. 1, the present invention is connected to an input terminal to which an input signal of an L channel or an R channel of a monaural signal or a stereo signal is applied and a low signal of the input signal connected to the input terminal. First low frequency band amplifier 10 for amplifying a frequency signal component and the first low frequency band amplifier 1
A first power amplifier 21 connected to the 0 output and a second low frequency band amplifier 24 connected to the output of the first low frequency band amplifier 10 and amplifying a low frequency component of the output signal and the second low frequency band amplifier 24. Phase inverter 23 connected to the output and second power amplifier 2 connected to the output of the phase inverter 23
2, a first output terminal 21a connected to the output of the first power amplifier 21, a second output terminal 22a connected to the output of the second power amplifier 22, a low-pitched loudspeaker 42, a mid / high-pitched loudspeaker 41, and a low-pass filter. 30, the one input end of the speaker 41 for middle and high frequencies is connected to the first output terminal 21a and the other input end is connected to the ground, respectively, and one input end of the speaker 42 for bass is described above. The other input end is connected to the first output terminal 21a via the low-pass filter 30 and the second input terminal 21a via the low-pass filter 30.
The loudspeaker is connected to each of the output terminals 22a.

[Embodiment] FIG. 1 shows a circuit block diagram of an embodiment of the present invention. In FIG. 1, the first low frequency band amplifier 10 uses a fixed resistor R3 and a variable resistor VR as a feedback resistor of the operational amplifier A,
An impedance element formed of a series connection of capacitors C1 and R4 and a semiconductor inductance L1 is connected between the midpoint of the variable resistor VR and the ground so that the amplification degree in a certain low band can be varied. The circuit configuration of the second low frequency band amplifier 24 is the same as that of the first low frequency band amplifier 10, and includes an operational amplifier A, a fixed resistor R ₈ and a variable resistor V.
The resonance frequency of the impedance element is selected to have the same value, which is composed of R, the capacitor C ₄ , the resistor R _9, and the semiconductor inductance L ₂ . Then, the second low frequency band amplifier 2
The amplification factor at the resonance frequency of No. 4 is selected to be larger than that of the first low frequency band amplifier 10. The low pass filter 30 includes a coil L3 and a capacitor C3, and the cutoff frequency thereof is appropriately selected. The speaker device 40 includes a mid-high range speaker 41 and a low-range speaker 42. The first power amplifier 21 and the second power amplifier 22 are power amplifiers of positive phase or negative phase between the input and output, and the phase of the input signal passing through the second power amplifier 22 is 180 degrees by the phase inverter 23. Will be done.
When the input and output of the first power amplifier 21 are in positive phase and the input and output of the second power amplifier 22 are in opposite phase, the phase inverter 23
Are included in the second power amplifier 22.

Then, one input end (+) of the mid-high range speaker 41 is connected to the first output terminal 21a (hot side terminal), and the other input end (-) is connected to the ground side terminal 21b of the first power amplifier 21, respectively. One input end (+) of the bass speaker 42 is connected to the first output terminal 21a (hot side terminal) via the low-pass filter 30, and the other input end (-) is connected to the second output via the low-pass filter 30. The terminals 22a (hot side terminals) are respectively connected.

In the loudspeaker according to the embodiment of the present invention, the bass range can be enhanced by the first low frequency band amplifier 10 and the second low frequency band amplifier 24, and the first output terminal 21a of the output of the first power amplifier 21 and the first output terminal 21a. The output between the output of the two-power amplifier 22 and the second output terminal 22a is supplied to the bass speaker 42 so that the bass range can be expanded and enhanced. Moreover, when the low-frequency signal and the high-frequency signal are input at the same time, the input signal of the first power amplifier 21 becomes a level lower than the input level of the second power amplifier 22, so that the output signal of the first power amplifier 21 has waveform distortion. Therefore, the sound reproduced from the mid-high range speaker 41 is not distorted, and the output between the first output terminal 21a of the output of the first power amplifier 21 and the second output terminal 22a of the output of the second power amplifier 22 is not generated. The low-pass filter 30 cuts off the high frequency component and supplies the signal to the low-pitched speaker 42. The low-pitched speaker 42 does not reproduce the high-frequency signal accompanied by the intermodulation distortion due to the high-frequency cutoff characteristic. Only the signal will be reproduced. In other words, the amplitude of the low frequency signal is equal to the clip level of the first power amplifier 21 and the second power amplifier 2
Up to the clip level Vc determined from the clip level of 2, the reproduced sound of the mid-high range speaker 41 is not distorted, and the reproduced sound of the bass speaker 42 is not distorted. It is possible to measure the expansion of the reproduced sound pressure level of the low frequency signal.

Effect of the invention: The loudspeaker of this invention can expand and enhance the low range,
Two SEPP-OTL circuit type amplifiers are sufficient as an amplifier for driving the mid-high range speaker 41 and the low-range speaker 42, which is inexpensive. Moreover, when the low-frequency signal and the high-frequency signal are simultaneously input, not to mention only the low-frequency signal, the reproduced sound of the high-frequency signal is not distorted, and the low-frequency signal is clipped by the first power amplifier 11. The amplitude can be expanded to a clip level Vc determined by the level and the clip level of the second power amplifier 12, and a reproduced sound without distortion can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining the present invention, and FIG. 2 is a block diagram for explaining a conventional example. 10 ... First low frequency band amplifier, 21 ... First power amplifier,
22 ... 2nd power amplifier, 23 ... Phase inverter, 24 ... 2nd
Low-frequency band amplifier, 30 ... Low-pass filter, 40 ... Speaker device, 41 ... Mid-high range speaker, 42 ... Bass speaker.

Claims (1)

[Scope of utility model registration request] 1. An input terminal to which an input signal is applied, a first low frequency band amplifier (10) connected to the input terminal and amplifying a low frequency signal component of the input signal, and the first low frequency band amplifier (10). ) A first power amplifier (2
1) and a second low frequency band amplifier (24) connected to the output of the first low frequency band amplifier (10) and amplifying a low frequency component of the output signal, and connected to an output of the second low frequency band amplifier (24). A phase inverter (23), a second power amplifier (22) connected to the output of the phase inverter (23), and a first output terminal (21a) connected to the output of the first power amplifier (21). A second output terminal (22a) connected to the output of the second power amplifier (22), and a bass speaker (4
2), a mid-high range speaker (41) and a low-pass filter (30). One input end of the mid-high range speaker (41) is connected to the first output terminal (21a) and the other input end is grounded. And one input end of the bass speaker (42) is connected to the first output terminal (21a) via the low pass filter (30) and the other input end is connected to the low pass filter (30). A loudspeaker, which is connected to each of the second output terminals (22a) via a sound output device.