JPH0549100A - Sound reproducing device - Google Patents

Abstract

PURPOSE:To realize the sound reproducing device in which the surrounding effect is improved and a vocal level is neither decreased nor locarized toward a rear position. CONSTITUTION:The reproducing device is provided with a surround circuit 7 which implements signal processing as addition and subtraction of a difference (R-L) signal between an R channel signal and an L channel signal subject to phase delay to/from the R channel signal and the L channel signal, a detection circuit detecting the (R+L) signal, a band pass filter F5 passing the detected (R+L) signal at a medium sound frequency band and a mixing circuit mixing the signal after passing through the band pass filter with the R channel signal and the L channel signal respectively.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an R channel signal and an L channel signal.
The present invention relates to a sound reproducing device having a surround circuit that performs a signal process of delaying a phase difference (RL) signal of channel signals and adding and subtracting the signal to and from the R channel signal and the L channel signal again.

[0002]

2. Description of the Related Art In recent years, a sound reproducing device has been incorporated with many surround functions in order to reproduce a richer sense of reality. An example of the above-described conventional sound reproducing device will be described below with reference to the drawings.

FIG. 4 shows a circuit configuration of a conventional sound reproducing device. In FIG. 4, 7 is a surround circuit block, and in this surround circuit block 7,
1 is an R channel signal input terminal, 2 is an L channel signal input terminal, 3 is an (RL) signal detection circuit, 4 and 6 are low pass filters, 5 is a phase delay circuit, and S1 is a surround ON / OFF switch. Is. A1 and A2 are buffer amplifiers, C1, C2, C3 and C4 are coupling capacitors, and A7 and A8 are mixing amplifiers. The (R-L) signal detected by the (R-L) signal detection circuit 3 passes through the low-pass filter -4 and is then delayed (Δt) by the phase delay circuit 5, and further received by the low-pass filter-. 6 through which the R channel is added and mixed by a mixing amplifier A7 to obtain R + Δt.
(RL) is output via the coupling capacitor-C3, the L channel is subtractively mixed in the mixing amplifier A8, and L- [Delta] t (RL) is output via the coupling capacitor-C4.

Next, VR1 and VR2 are volume volumes.
, A15 and A16 are power amplifiers, C26 and C2
7, C28 and C29 are coupling capacitors, S
P5 and SP6 are speakers, and the R channel output of the surround circuit block 7 is the volume control VR1.
And the power amplifier A15 via the coupling capacitor-C26, and the output thereof is also input to the speaker SP5 via the coupling capacitor-C28 to reproduce sound. On the other hand, the L channel output is the volume control VR2 and the coupling capacitor-C27.
To the power amplifier A16, and its output is also input to the speaker SP6 via the coupling capacitor-C29 for sound reproduction.

[0005]

However, in the conventional sound reproducing apparatus as described above, the difference signal (RL) signal between the R channel signal and the L channel signal is phase-delayed, and the R channel signal and the L channel signal are reproduced again. The output on the R channel side of the surround circuit that performs signal processing to add and subtract to R + Δt (RL) and the output on the L channel side are L-Δt (RL), and in order to produce the surround effect, Δt If you mix a lot of (RL) components,
The ratio of the in-phase component of the R channel and the L channel decreases. In particular, in a source having a vocal, the vocal is often the above-mentioned in-phase component, which is audible.
There was a problem that the vocal level was lowered and localized toward the rear.

In view of the above-mentioned conventional problems, the present invention has been made with the object of providing an audio reproducing apparatus which has a high surround effect and which does not lower the vocal level and localize backward. is there.

[0007]

In order to solve the above-mentioned problems, the sound reproducing apparatus of the present invention delays the phase of the difference signal (RL) between the R channel signal and the L channel signal, and again restores the R channel signal and A surround circuit that performs signal processing for adding and subtracting to and from an L channel signal, a detection circuit that detects an (R + L) signal, a bandpass filter that passes the detected middle (R + L) signal, and this bandpass filter. A mixing circuit for mixing again the R channel signal and the L channel signal after passing.

[0008]

According to the present invention, with the above-described structure, the middle frequency range of the (R + L) signal detected by the detection circuit for detecting the (R + L) signal is passed through the bandpass filter, and the signals of the R channel and the L channel are mixed again. The in-phase component of the R channel and L channel in the midrange is corrected.

[0009]

Embodiments of the sound reproducing apparatus of the present invention will be described in detail below with reference to FIGS.

In FIG. 1, reference numeral 7 denotes a surround circuit block, which is a circuit similar to the above-mentioned conventional example. VR1
And VR2 are volume volumes, C5 to C17 and C21.
Is a coupling condenser, A9 and A10 are buffer amplifiers, F1 and F3 are low-pass filters, and F.
2 and F4 are mid-high range pass filters, A11 to A14
Is a power amplifier, SP1 and SP4 are mid-high range speakers.
Car, SP2 and SP3 are low range speaker, R22
~ R33 is a resistor, Q1 and Q2 are transistors, C1
9-C20 is condenser, S2 is surround ON / O
It is a switch for FF and works in conjunction with the switch S1 for surround ON / OFF.

The R channel output of the surround circuit block 7 is connected to a volume volume VR1 to set the volume, and the movable piece of the volume volume VR1 has a buffer amplifier A9 via a coupling capacitor C5.
Connected to. The output of the buffer-amplifier A9 is connected to the mid-high range pass filter-F1 and the low-range pass filter-F2, and the output of the mid-high range pass filter-F1 is a coupling capacitor-C8, a power amplifier A11 and a coupling capacitor. -Speaker for mid-high range via C14-
It is connected to the car SP1 and acoustically reproduces the mid-high range of the R channel signal. The output of the bass filter F2 is sent to the bass speaker SP2 via the coupling capacitor C9, the resistor R24, the coupling capacitor C10, the power amplifier A12 and the coupling capacitor C15. It is connected and acoustically reproduces the low frequency range of the R channel signal.

Similarly, the L channel output of the surround circuit block 7 is also connected to the volume volume VR2 to set the volume, and the movable piece of the volume volume VR2 is a buffer amplifier via a coupling capacitor C6. A
The output of the buffer-amplifier A10 is connected to a mid-high range pass filter-F4 and a low-range pass filter-F3, and the output of the mid-high range pass filter-F4 is a coupling capacitor-C13 and a power source. Amplifier A
14 and a coupling capacitor-C17 are connected to the mid-high range speaker SP4 to acoustically reproduce the mid-high range of the L channel signal, and the output of the low-pass filter-F3 is the coupling capacitor-C11. , Resistance R2
6, coupling capacitor-C12, power amplifier A
13 and the coupling capacitor-C16,
It is connected to the low range speaker SP3, and reproduces the low range of the L channel signal.

The output of the buffer amplifier A9 is connected via a resistor R22, and the output of the buffer amplifier A10 is connected via a resistor R23.
It is connected to one terminal of C7 and the other terminal of the coupling capacitor-C7 is connected to the emitter of the transistor-Q1. Here, the resistors R22 and R23 are (R
+ L) functioning as a detection circuit for detecting the signal. Further, the transistor-Q1 constitutes a base-grounded amplifier, and R30 is an emitter-resistor connected between the emitter of the transistor-Q1 and the ground, and R2.
Reference numeral 9 is a base resistor, which is connected between the base of the transistor Q1 and the collector, and C18 is a capacitor for grounding the base, which is connected between the base of the transistor Q1 and the ground. To be done.

The resistor R28 and the capacitor C19 are connected in parallel to serve as the collector-load of the transistor Q1. One of the connection points is connected to the collector of the transistor Q1 and the other is connected to the power supply. Further, the collector of the transistor Q1 is connected to the base of the transistor Q2 via the capacitors C20 and C21. The transistor Q2 constitutes an emitter follower, R31 is a bias resistor connected between the base and collector of the transistor Q2, and R33 is an emitter resistor which is the emitter of the transistor Q2.
And the ground, and the collector of the transistor Q2 is connected to the power supply. The connection point between the capacitors C20 and C21 is grounded via the resistor R32, and the surround ON / OFF switch S2 is turned off.
It is connected to the side terminal. The ON-side terminal of the surround ON / OFF switch S2 is open, and the common terminal is grounded. Here, a low-pass filter including a resistor R28 and a capacitor C19, a resistor R32, and a capacitor-
A bandpass filter F5 configured to pass a middle frequency range including a combination of a high frequency range pass filter including C20 is configured.

Furthermore, the collector of the transistor Q2 is
The resistor R25 is connected to the connection point between the resistor R24 and the coupling capacitor-C10, and the resistor R27 is connected to the connection point between the resistor R26 and the coupling capacitor-C12. Here, the resistors R25 and R27 are
A mixing circuit that mixes the signal that has passed through the band pass filter F5 into the R channel signal and the L channel signal again is configured.

The operation of the sound reproducing apparatus configured as described above will be described below. The operation of the surround circuit block 7 is similar to that of the conventional example. R-channel signal of buffer-amplifier A9 and buffer-amplifier A10
The (R + L) signal of the L channel signal is detected by the resistors R22 and R23, and the voltage is amplified by the transistor -Q1. Further, through the band-pass filter F5, the emitter follower Q2 serves as a buffer, and the R channel side is mixed via the resistor R25 and the L channel side is mixed via the resistor R27. Also,
When the operation of the surround ON / OFF switch S2 is OFF, the signal line is grounded and the (R + L) signal is not output.

FIG. 2 shows each speed in the case of surround ON.
The sound reproduction output characteristics from the mosquitoes are shown in the figure. A is a bass range filter through the bass range filter F2 or F3.
Signal level reproduced by sound from SP2 or SP3,
B is a signal level which is reproduced acoustically from the mid-high range speaker SP1 or SP4 through the mid-high range filter F1 or F4, and C is reproduced acoustically from the low range speaker SP2 or SP3 (R + L). The signal level.

[0018]

As described above, according to the present invention, the signal processing for delaying the phase of the difference signal (RL) between the R channel signal and the L channel signal and again adding or subtracting it to the R channel signal and the L channel signal is performed. Surround circuit to perform, (R
+ L) detection circuit for detecting the signal and the detected (R
+ L) a bandpass filter that passes the middle and middle frequencies of the signal, and
By providing a mixing circuit for again mixing the R channel signal and the L channel signal after passing through this bandpass filter, the surround effect is enhanced, and the sound level is lowered and the vocal level is not localized to the rear. be able to.

[Brief description of drawings]

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

FIG. 2 is a sound reproduction output characteristic diagram from each speaker in the case of surround ON.

FIG. 3 is a circuit configuration diagram of a sound reproducing device in a conventional example.

[Explanation of symbols]

1 R channel signal input terminal 2 L channel signal input terminal 3 (RL) signal detection circuit 5 Phase delay circuit 7 Surround circuit F5 Bandpass filter R22, R23 (R + L) Resistor configuring the signal detection circuit R25, R27 Mixing circuit Resistance

Claims (1)

[Claims] 1. A surround circuit for performing signal processing for phase-delaying a difference (RL) signal between an R channel signal and an L channel signal, and adding and subtracting the signal again to the R channel signal and the L channel signal, and (R + L). A detection circuit for detecting the signal, a bandpass filter for passing the detected inner and middle frequencies of the (R + L) signal, and a mixing circuit for mixing again the R channel and L channel signals after passing the bandpass filter. A sound reproducing device characterized by being provided.