JPS6019400A - Sound field correcting device in asymmetrical stereo listening position - Google Patents

Abstract

PURPOSE:To attain localization of a sound image with spread on a line tying two speakers even if a stereo phonic signal is listened to at an asymmetrical position to two speakers by introducing a channel signal of R channel and L channel signals of 2-channel stereo phonic signals to the speakers via a correcting device. CONSTITUTION:In Fig., 30 is a detecting circuit extracting an envelope of an input signal, 31 is a transient emphasis circuit emphasizing the change in the amplitude of the output, and 32 is an analog multiplier multiplying an output of the transient emphasis circuit 31 and the input signal applied to the detecting circuit 30, and they constitute the correcting device 33. Suppose that a listener 34 is at an asymmetrical position to the two speakers, then contacts 16, 17 are set to changeover contacts 13, 15 so as to emphasize the sound volume of an L speaker 29 and contacts 24, 25 are set to the position of changeover contacts 21, 23. Thus, the moment there is a change in the input to a channel apart from the listner, since the channel signal is emphasized, it is sensed by the listener that the sound image is moved momentarily and the sound field is spread on a line tying both speakers 28, 29.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention enables, when listening to a two-channel stereo signal with two speakers at asymmetric positions, a sound image is spread and localized on a line connecting the two speakers. The present invention relates to a sound field correction device for an asymmetric stereo listening position.

Prior Art and Problems Normally, in stereo broadcasting, l is obtained by receiving and demodulating the stereo broadcast as shown in FIG.

When listening to the reproduced sound at the vertices of an equilateral triangle whose two points are the positions of speaker 1 that reproduces the channel signal and speaker 2 that reproduces the R channel signal, the sound image for the listener 3 is the same as that of the two speakers 1. ．． The source is generated so as to spread and be localized on the line connecting 2. Therefore, if the listening point is biased towards one of the speakers, the entire sound image will be localized to the speaker on the biased side, for example, as shown in FIG. 2, if the volumes are equal. Conventionally, in such a case, correction is made by lowering the volume of the speaker closer to the listener 3. However, when the volume of the speaker closest to the listener is lowered, the sound image moves toward the other speaker, but when the volume is lowered below a certain level, the sound image is localized to the other speaker, and the two speakers are The sound image spreads along the connecting line and cannot be localized.

Purpose of the Invention The present invention improves these conventional drawbacks, and
The purpose is to provide a sound field correction device that can spread and localize the sound image on a line connecting the two speakers even when listening to a two-channel stereo signal at asymmetric positions of the two speakers. .

Structure of the Invention In order to achieve the above object, the present invention includes a detection circuit for extracting the envelope of a channel signal, a transient emphasis circuit that receives the output of the detection circuit as an input, and a transient emphasis circuit that receives the output of the transient emphasis circuit and the A correction device comprising a multiplier for generating a corrected channel signal by multiplying the corrected channel signal by the channel signal is provided. It is configured to be guided to a speaker via a correction device, so as to emphasize changes in the volume of the speaker located far away from the listening point.

Embodiment of the Invention FIG. 3 is a block diagram of essential parts of an embodiment of the invention. In the figure, 10 is a terminal to which the R channel signal of FM stereo broadcasting obtained by demodulating with a stereo demodulation circuit (not shown) is added, 11 is a terminal to which the channel signal obtained by demodulation is also added, and 12 to 15 are switches. Terminal and switching terminal 12.1
5. Switching terminal 13. 14 are connected to each other. 1
6.17 are contacts which are interlocked with each other; when the contact 16 is located on the switching terminal 13 side, the contact 17 is located on the switching terminal 15 side; when the contact 16 is located on the switching terminal 12 side, the contact 17 is located on the switching terminal 12 side.
is located on the switching terminal 14 side.

Further, 18 and 19 are terminals, 20 to 23 are switching terminals, and switching terminals 20.23 and 21.22 are connected to the tiles. 24.25 is a contact point, and this contact path,
Both of them are linked to each other. 26 and 27 are power amplifiers, the output of the power amplifier 26 is connected to the R speaker 28 for reproducing the R channel signal, and the output of the power amplifier 27 is 1. It is connected to the I7 speaker 29 for channel signal reproduction.

Further, 30 is a detection circuit that extracts the envelope (envelope component) of the input signal, 31 is a transient emphasis circuit that emphasizes changes in the amplitude of the output, and 32 is a circuit that connects the output of the transient emphasis circuit 31 and the detection circuit 30. This is an analog multiplier that multiplies the applied input signal, and these constitute the correction device 33. The inputs of this correction device 33 are connected to the switching terminals 12, 15, and the output thereof to the terminals 18.19. In addition, in FIG. 3, 34 is the listener, and 35a to 35d are the positions of the sound image as seen from the listener 34.

Now, suppose that the listener 34 is in an asymmetrical position with respect to the two speakers as shown in FIG. .15 side, and the contacts 24 and 25 are set to the switching contacts 21 and 23 sides. That is, the L channel signal is corrected and the R channel signal is output as is.

FIG. 4 is a diagram showing an example of the signal waveforms of each part of the apparatus shown in FIG.
b) is the output signal of the detection circuit 30, (C) is the output signal of the transient emphasis circuit 31, and (d) is the output signal of the analog multiplier 32 (input signal at terminal 19).
This shows the temporal changes in the manual borrowing of terminal I8 and terminal I8, respectively. The audio signals from speakers 28 and 29 are shown in the same figure (
d) becomes mutual resentment form. Also, in Fig. 4, '1゛1~
'1' and 5 each indicate a certain time.

At time 1.1, it is applied to the power amplifiers 26 and 27, and the magnitude of the channel signal and the R channel signal are the same, so for the listener 34, the nearby R channel signal becomes dominant, and the sound image is It is localized at position 35a in the figure.

At time T2, the rising edge of the L channel signal is emphasized by the transient emphasis circuit 31, and the volume of the L channel signal is increased compared to the current level, so that the listener 34
The sound image for this is localized at the position 35d in FIG.

At time 1-3, the volume of the L channel signal is at time '
Since it is lower than when I'2, the sound image is slightly drawn toward the 1 channel and is localized at the position 35c in FIG. 3.

At time 'I'4, the volume of the L channel signal is further lower than at time 'I'3, so the sound image is drawn a little closer to the R channel side and localized at position 35b in FIG. 3.

Then, at time T5, the magnitudes of the L channel signal and the R channel signal become the same again, so the nearby R channel signal becomes dominant again for the listener 34, and the sound image becomes the same as 358 in FIG. It will be fixed in position.

In this way, in this embodiment, the moment there is a change in the input of a channel far away from the listener, that channel signal is emphasized, so the listener perceives that the sound image has moved instantaneously, and the sound image changes. 35 a -"35 b→35 c -
As a result of the short change of 35 d, the sound field spreads along the line connecting both speakers 28 and 29.

Note that by switching the contacts 16, 17, 24, and 25, it is possible to handle listening at an asymmetric position on the opposite side. Of course, if the asymmetrical position is limited to either one, switching means such as these contacts can be omitted.

Figure 5 is an electrical circuit diagram showing an embodiment of the transient emphasis circuit 1-831, in which a capacitor C is connected in series between the input glass 50 and the output glass 5, and a resistor is connected in parallel to this capacitor. In this case, the resistor R1 is connected to the resistor R2, and the resistor R2 is grounded. When the input signal v1 applied to the terminal 50 changes from the regular state, vI appears as it is at first at the output Vl) due to the charging current of the capacitor C,
As time passes, a voltage determined by the voltage division ratio of resistors 1 and 1°R2 is output. The travel time of the above sound image is the capacitor C
The degree of change in volume is determined by the ratio of resistors R1 and R2.

According to experiments, the time constant C-R2 is about 33m5, and the resistance R
If the ratio of ,,I,R2 is set to about 1:3, the movement of the sound image becomes natural, and the sound image spreads to the line -L connecting the speakers 28 and 29 and is localized.

Note that the analog multiplier 32 in FIG. 3 has, for example, multiplication characteristics as shown in FIG. 6, and therefore, it is also possible to use a so-called electronic volume that can obtain similar multiplication characteristics.

FIG. 7 is a block diagram of main parts of another embodiment of the present invention,
The same symbols as in FIG. 3 indicate the same parts, and 70 is an analog adder. This embodiment is provided with an adder 70 that adds the output of the analog multiplier 32 and the input applied to the detection circuit 30. With this configuration, the movement of the sound image becomes more natural, and the sound image is further improved. This makes it possible to expand the number of people.

As described in detail, according to the present invention, even when listening to a two-channel stereo signal from two speakers at asymmetric positions, the sound image can be spread and localized on a line connecting the two speakers. This makes it possible to listen to stereo broadcasts that expand and make you feel warm. Furthermore, almost the same effect can be obtained even if the listening point is slightly shifted. It is undeniable that the sound quality deteriorates to some extent when using the sound field correction device of the present invention, but according to the experimental results, the deterioration is not so noticeable, and the sense of spaciousness is improved, which improves overall listening quality. The feeling improves.

The present invention can be applied to stereo receivers that do not allow listening at asymmetrical positions, such as in-vehicle stereo receivers in which speakers are installed on both sides of an instrumental panel in a vehicle interior.

[Brief explanation of drawings]

1 and 2 are diagrams showing the relationship between the listening position and the sound image, FIG. 3 is a block diagram of the main part of an embodiment of the present invention, and FIG.
The figure is a diagram showing an example of the signal waveform of the third illustrated device stand at that time, and FIG.
FIG. 6 is a diagram showing the multiplication characteristics of the analog multiplier 32, and FIG. 7 is a main part block diagram of another embodiment of the present invention. 10 is a terminal to which an R channel signal is applied, 11 is a terminal to which an L channel signal is applied, 12 to 15. 20 to 23 are switching to l
jl terminal, 16.17.24.25 are contacts, 26.27 is a power amplifier, 30 is a detection circuit, 31 is an I/Langien 1-emphasis circuit, 32 is an analog multiplier, 33
is a correction device #, 34 is a listener, 35a to 35d are positions of the sound image as seen from the listener 34, and 70 is an analog adder. Patent applicant Fujitsu Ten Co., Ltd. Representative patent attorney Gogo Tamamushi 1 person outside the department No. 4 Fig. 5 Fig. 6 Fig. 70

Claims (1)

[Claims] A detection circuit that extracts an envelope of a channel signal, a transient emphasis circuit that receives the output of the detection circuit as an input, and a multiplier that multiplies the output of the transient emphasis circuit and the channel signal to generate a corrected channel signal. in an asymmetric stereo listening position, characterized in that it has a correction device comprising: a correction device, and is configured such that only one of an R channel signal and an L channel signal of a stereo signal is guided to a speaker via the correction device. Sound field correction device.