JPH0633760Y2 - Audio expansion device for audio equipment - Google Patents

Description

[Detailed description of the device] [Industrial applications]

The present invention relates to a sound expansion (wide) device in stereo audio equipment.

[Prior art]

Conventionally, there is an apparatus of this type shown in FIG. In the figure, IC ₁ is a differential amplifier, R ₁ , C ₁ and R ₂ are circuit elements mainly for obtaining L component low-pass filter characteristics, and R ₃ and R ₄ are mainly for obtaining LR component. It is configured as a circuit element, and L ₀ and R ₀ are an L channel output and an R channel output, respectively. In the sound amplification device in the conventional audio equipment configured as described above, ω _L and ω _H are obtained as follows according to the constants of the respective circuit elements described above. That is, ω _L = 1 / C ₁ (R ₁ + R ₂ ) ・ ・ (1) ω _H = 1 / C ₁ [R ₂ − (R ₁・ R ₂ / R ₃ )] ・ ・ (2) (1) , (2), the L channel output L ₀ is L ₀ = [(1 + jω / ω _H ) / (1 + jω / ω _L )] L +
K (L-R) ·· ( 3) where it is K = R ₄ / R _3. That is, also from the relationship between the frequency and the L channel output L ₀ shown in FIG. 4, the L channel output L ₀ is attenuated with respect to the L channel input L from the frequency ω _L to ω _H ,
After that, it has a constant characteristic. Further, the L channel output L ₀ by L-R is K independent of frequency, that is,
It is designed to have a constant output level determined by R ₄ / R ₃ .

[Problems to be solved by the device]

In the conventional sound amplification device having the above-described configuration, if the L-R component is increased in order to emphasize the expansive feeling of the sound field, the original sense of localization of the sound field is lost, resulting in unnatural sound. It will be. The above-mentioned phenomenon is a problem due to the fact that desired changes cannot be given to the main component and difference component of the sound. The present invention has been made in order to solve the above-mentioned conventional problems, and provides more freedom in frequency characteristics and output level with respect to the main component difference component of the sound so that the sound field of The purpose is to improve the spaciousness and naturalness.

[Means for solving problems]

Two input channels L, R and one output channel L ₀
And the two input channels L and R and the output channel L ₀
A differential amplifier IC ₁ which is provided between, between the non-inverting input and a reference potential of the input channels L and resistor R ₁ are connected in series between the non-inverting input of the differential amplifier IC ₁ and the differential amplifier IC ₁ A low-pass filter mainly composed of a series circuit of a resistor R ₂ and a capacitor C ₁ for passing a low frequency component of an input channel L as a main component, and a series circuit between the input channel R and an inverting input of a differential amplifier IC _1. connected between the output channels L ₀ connected resistor R ₃ and a series circuit of the resistor connected in parallel a resistor R ₃ R ₅ and a capacitor C ₂ and the inverting input resistor
An output circuit for an output channel L ₀ composed of a circuit composed of R ₄ , one output channel L _0, and a configuration similar to that of the output circuit for the output channel L ₀ and having an input channel R as a main component, One of the input channels L, R is an output channel R ₀ output circuit connected to the output circuit and the reverse for the output channel L _0, the output channel L ₀ and R ₀ output circuit is shown by the following formulas, respectively output channels L _0, to output an output L ₀ and R ₀ of R _0, which is the main component input channels L output channels L ₀ output circuit and the output channel R ₀ output circuit
The frequency characteristics of the input channel R and the input channel R each have a low-pass filter characteristic in which flat attenuation shifts at four frequency points, and the difference components (LR) and (RL) are flat at two frequency points. It has a high frequency characteristic that makes a rising transition,
A voice expansion device in an audio device, wherein the difference component is added to each of the main components and output.

【Example】

FIG. 1 is a circuit diagram showing an embodiment of the present invention, in which IC ₁ , R ₁ , R ₂ , R ₃ , R ₄ , and C ₁ are the same parts as the same reference numerals in FIG. 2 showing a conventional example. Or indicates the corresponding part, C ₂ , R ₅
The series circuit provides the L component (principal component) with the low-pass characteristic in the specific region in the high frequency range, and the L-R component (difference component) similarly obtains the high-pass characteristic in the specific region in the high frequency range. It is configured for. A voice expansion device according to the present invention configured as described above,
In a so-called stereo wide circuit, the L channel output L ₀ is Therefore, if the transfer functions of the L component and the L-R component are A and B, Becomes Therefore, when the poles ω _L1 , ω _L2 , ω _H1 , ω _H2 and ω _H3 , ω _H4 of the L component and the L-R component are obtained, first, ω _H3 and ω _H4 are ω _H3 = 1 / [C ₂ (R ₃ + R ₅ )] ··· (7) ω _H4 = 1 / (C ₂ R ₅ ) ·· (8) ω _L1 and ω _H2 are ω _L1 = 1 / [C ₁ (R ₁ + R ₂ )] ・ ・ (9) ω _H2 = 1 / (C ₂ R ₅ ) ・ ・ (10) ω _L2 and ω _H1 are _calculated from the numerator of equation (5). _{However, k = {(C 2 R} 3 R 5) 2 + (C 1 R 1 R 4) 2 + 2C 1 C 2 R 1 R 3 R 4 R 5 + 4C 1 C 2
_{C 3 (R 1 R 3 R} 4 -R 2 R 3 R 5)} becomes ^1/2. FIG. 2 shows ω _L1 , ω obtained from the equations (4) to (8).
_L2, is a diagram showing the correlation between the _{ω H1, ω H2, ω H3} , L, R and the frequency and L channel output L _0. That is, the output level of the acoustic main component L changes in a flat-attenuation-flat-attenuation-flat process at the circulating wave numbers ω _L1 , ω _L2 , ω _H1 , and ω _H2 , and the difference component L-
The output level of R changes at the same wave numbers ω _H3 and ω _H2 by following a flat-up-flat process.

As described above, the present invention is configured so that the frequency characteristic can be changed at 4 points for the main component and at 2 points for the difference component. In the treble range, the difference component is reduced to maintain the naturalness, and the difference component can be increased in the high range where the sound field spreads frequently.Therefore, it is possible to achieve both the sound field spread and the naturalness. is there.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram of an audio expansion device according to an embodiment of the present invention, FIG. 2 is a diagram showing frequency characteristics by the circuit of FIG. 1, and FIG. 3 is a conventional audio expansion. FIG. 4 is a circuit diagram of the device, and FIG. 4 is a diagram showing frequency characteristics by the circuit of FIG. IC ₁ ... Differential amplifier, L ... L channel input, R ... R channel input, L ₀ ... L channel output, R _{1 to} R ₅ ... Resistor,
C _1, C ₂ ... capacitor.

Claims (1)

[Scope of utility model registration request] 1. Input channels L, R, one output channel L ₀ , a differential amplifier IC ₁ provided between the two input channels L, R and output channel L ₀ , and the input channel. consisting series circuit of series connected resistors R ₁ and non-inverting input resistor connected between the reference potential R ₂ and the capacitor C ₁ of the differential amplifier IC ₁ between the non-inverting input of the L and the differential amplifier IC ₁ A low-pass filter that mainly passes the low-frequency component of the input channel L as the main component, a resistor R ₃ connected in series between the input channel R and the inverting input of the differential amplifier IC ₁ , and a resistor R ₃ connected in parallel to the resistor R _3. Resistor R ₅ and capacitor
An output circuit for an output channel L ₀ , which is composed of a series circuit of C ₂ and a resistor R ₄ connected between the inverting input and the output channel L ₀ , one output channel L _0, and the output channel L ₀ and ₀ output circuit for the same structure as the main component input channel R, the two input channels L, and the R output circuit for output channels R ₀ connected to the output circuit and the reverse for the output channel L ₀ wherein the output channels L ₀ and R ₀ output circuit to output an output L ₀ and R ₀ of the output channels L _0, R ₀ shown by the following formula, respectively, output channels L ₀ output circuit and the output channel Input channel L, which is the main component of the output circuit for R ₀
The frequency characteristics of the input channel R and the input channel R each have a low-pass filter characteristic in which flat attenuation shifts at four frequency points, and the difference components (LR) and (RL) are flat at two frequency points. It has a high frequency characteristic that makes a rising transition,
A voice expansion device in an audio device, wherein the difference component is added to each of the main components and output.