JP4530639B2 - Sound field adjustment device, surround circuit, and vehicle-mounted acoustic device - Google Patents

Description

The present invention relates to a sound field adjusting device , a surround circuit, and an in-vehicle audio device , and more particularly, is used by being connected to a surround device including a surround signal processing circuit that generates a surround signal based on a difference component of a two-channel stereo signal. The present invention relates to improvements in sound field adjusting devices , surround circuits, and in-vehicle acoustic devices .

  2. Description of the Related Art Conventionally, as a system for reproducing realistic sounds, a two-channel stereo system is known in which two speakers are arranged on the left and right in front of a listener and different sounds are reproduced from each speaker. On the other hand, a surround device is also known in which speakers are also arranged on the left and right behind the listener to reproduce stereophonic sound and further increase the sense of reality.

  In the former surround device, the sound of the four speakers in total, two in the front and two in the rear, is created separately for four channels, and the sound in each channel is reproduced by the four speakers corresponding to each channel. It was. However, in recent years, due to advances in circuit technology, a surround signal processing circuit is used to generate a 4-channel output signal from a 2-channel stereo signal, and these 4-channel output signals are placed on the left and right of the listener's front and rear, respectively. Surround devices that reproduce with four speakers have appeared (see, for example, Patent Documents 1 and 2).

  Two-channel stereo signals (left channel signal L and right channel signal R) are input to the surround signal processing circuit of such a surround device. The surround signal processing circuit internally processes the two-channel stereo signal, so that the channel signal FL reproduced by the left front speaker, the channel signal FR reproduced by the right front speaker, the channel signal RL reproduced by the left rear speaker, And four signals of the channel signal RR reproduced by the right rear speaker are generated and output.

JP-A-5-091600 (FIG. 4) Japanese Unexamined Patent Publication No. 7-040760 (FIGS. 1 and 2)

  However, such a surround signal processing circuit generally generates a 4-channel surround signal based on a difference component obtained by removing the correlation component of the stereo 2-channel signals L and R, for example, an (LR) component. When the separation of the input two-channel stereo signals L and R varies due to some cause, for example, electric field strength change at the time of FM radio wave reception or multipath noise, the surround signal is reduced by reducing the (LR) component. There is a problem that the volume of the sound is reduced, the volume of the sound output from the rear speaker is changed, and in the worst case, the sound is not output from the rear speaker.

  This problem will be described with reference to FIG. 1, for example, in the case where the 2-channel stereo signals L and R are reproduced from the radio waves received by the FM tuner, and the 4-channel stereo sound is reproduced from the 2-channel stereo signals L and R. .

  FIG. 1A shows the operation of the surround signal processing circuit 3 when the antenna 1 and the FM tuner 2 are installed in a strong electric field area. In a strong electric field region, the FM tuner 2 outputs L and R components of a two-channel stereo signal with high separation. At this time, the (LR) component is sufficient, and the surround signal processing circuit 3 uses the (LR) component to reproduce the channel signal FL reproduced by the left front speaker SPFL and the channel signal reproduced by the right front speaker SPFR. Four signals are generated and output: FR, a channel signal RL reproduced by the left rear speaker SPRL, and a channel signal RR reproduced by the right rear speaker SPRR. As a result, three-dimensional sound is reproduced by the four speakers SPFL, SPFR, SPRL, and SPRR.

  FIG. 1B shows the operation of the surround signal processing circuit 3 when the antenna 1 and the FM tuner 2 are installed in a weak electric field area. In the weak electric field region, the L and R components of the two-channel stereo signal with low separation are output from the FM tuner 2, and in the worst case, the output is monaural in which the L and R components are equal. At this time, the (LR) component is 0, and the surround signal processing circuit 3 can generate the channel signal FL reproduced by the left front speaker SPFL and the channel signal FR reproduced by the right front speaker SPFR, but the left rear speaker SPRL. The channel signal RL to be reproduced with the channel signal RR and the channel signal RR to be reproduced with the right rear speaker SPRR cannot be generated. As a result, sound is reproduced from the left front speaker SPFL and right front speaker SPFR, but no sound is output from the left rear speaker SPRL and right rear speaker SPRR.

As described above, in a reception situation where the separation of the two-channel stereo signals L and R changes depending on the electric field strength at the time of FM radio wave reception or fluctuates due to multipath noise, for example, the FM tuner is mounted on the vehicle. Occurs when.

Therefore, the present invention receives a radio wave including a two-channel stereo signal whose separation varies depending on the reception situation and demodulates the two-channel stereo signals L and R obtained by demodulation and the difference component (L -R), a sound field adjusting device is connected to a surround device that generates a 4-channel surround signal, and even if the separation of the 2-channel stereo signals L and R input to the surround device is deteriorated for some reason, The purpose of the field adjustment device is to prevent fluctuations in the level of sound coming from the rear speaker and the problem that no sound is produced at all.

The first embodiment of the sound field adjusting apparatus of the present invention that achieves the above object is generated from a left channel signal and a right channel signal input from a playback device that outputs a two-channel stereo signal, and these input signals. Surround signal processing means for generating a surround signal based on the difference signal, and the two-channel stereo signal is a sound field adjusting device connected to a surround device that is a received signal whose separation varies depending on reception conditions, The signal processing means outputs, as surround signals, at least two left and right forward sound surround signals coming from the front of the listener and at least one surround signal for the back incoming sound coming from the rear of the listener In addition, the sound field adjustment device adds to the line where the surround signal for the incoming sound is input. And a part of the surround signal for the forward incoming sound is guided to the adder as an added signal and added to the surround signal for the backward incoming sound .

The second embodiment of the sound field adjusting apparatus of the present invention that achieves the above object is generated from a left channel signal and a right channel signal input from a playback device that outputs a two-channel stereo signal, and these input signals. Surround signal processing means for generating a surround signal based on the difference signal, and the two-channel stereo signal is a sound field adjusting device connected to a surround device that is a received signal whose separation varies depending on reception conditions, The signal processing means outputs, as surround signals, at least two left and right forward sound surround signals coming from the front of the listener and at least one surround signal for the back incoming sound coming from the rear of the listener The sound field adjusting means is added to the line where the surround signal for the incoming sound is input. And a part of the signal for the left channel or the signal for the right channel is led to the adder as the addition signal and added to the surround signal for the backward incoming sound .

In the first or second mode, the received signal is a two-channel stereo signal demodulated by receiving FM radio waves .

The surround circuit of the present invention is a surround circuit to which a sound field adjusting device is connected, and a surround signal output from the surround circuit drives at least three speakers provided in the in-vehicle acoustic device. It is a signal.

Furthermore, the in-vehicle audio device of the present invention is an in-vehicle audio device including a surround circuit, and there are a plurality of types of playback devices that output 2-channel stereo signals, and means for selecting one of the playback devices is provided. The addition amount of the addition signal added to the surround signal for the incoming sound is controlled according to the type of the selected playback device.

  As a result, the separation of the stereo 2-channel signal input to the surround device has deteriorated for some reason by the sound field adjustment device connected to the surround device that generates the 4-channel surround signal based on the difference component of the stereo 2-channel signal. Even in this case, there is an effect that there is no occurrence of a problem that the sound output from the rear speaker does not fluctuate or does not generate any sound.

  Embodiments of a sound field adjusting device according to the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 2 shows the overall configuration of an embodiment of an audio system provided with the surround circuit 10 of the present invention. The audio system according to this embodiment includes a left front speaker SPFL disposed at the left front of the audio listener 30, a right front speaker SPFR disposed at the right front, a left rear speaker SPRL disposed at the left rear, and a right rear. 4 is a surround system using four right rear speakers SPRR.

  The audio system of this embodiment includes a tuner 2 connected to an antenna 1, a CD (compact disc) player 4, an MD (mini disc) player 5, and a cassette as audio playback devices that output two-channel stereo signals L and R. There is a player 6, and the signal output terminals of these playback devices are all connected to the changeover switch 7. The tuner 2 in this case is one of an AM stereo tuner, an FM stereo tuner, and a stereo TV tuner (for ground wave reception and satellite wave reception). In addition to MD, CD, and cassette players 4, 5, and 6, there are DVD (digital versatile disc) players, hard disk players, semiconductor memory playback devices, and the like. The changeover switch 7 outputs one of the two-channel stereo signals L and R output from these playback devices to the surround circuit 10. The changeover switch 7 can also be included in the surround circuit 10.

  Inside the tuner 2 is a front end 2A that converts the frequency of radio waves received by the antenna 1 and outputs an intermediate frequency, and detects the intermediate frequency to extract an audio signal, and generates two-channel stereo signals L and R therefrom. And a multiplex circuit 2B for outputting. From the front end 2A, the electric field strength signal of the radio wave received by the antenna 1 is output, and this electric field strength signal is input to the microcomputer 9 that controls the entire audio system.

  Connected to the microcomputer 9 is a playback device selector 8 for selecting any of the playback devices (tuner 2, CD player 4, MD player 5 and cassette player 6) that output two-channel stereo signals L and R. A switching signal corresponding to the playback device selected by the selector 8 of this playback device is output from the microcomputer 9 to the switch 7. As a result, only the output from the playback device selected by the selector 8 of the playback device is output to the surround circuit 10 through the changeover switch 7.

  Further, a signal indicating the separation of the received stereo signals L and R is output from the multiplex circuit 2B of the FM tuner 2 to the microcomputer 9, and the microcomputer 9 in the surround circuit 10 to be described later based on this separation signal. The mixing ratio correction circuit 20 is instructed to determine the mixing ratio of other signals to the rear speaker drive signal generated in the above. The mixing rate correction circuit 20 outputs instruction signals GL and GR for instructing the mixing rate of other signals to the surround circuit 10 based on an instruction from the microcomputer 9. The mixing rate instruction signals GL and GR will be described in detail in the following embodiments.

  The surround circuit 10, based on the two-channel stereo signals L and R input from the changeover switch 7, the signal FL to the left front speaker SPFL disposed at the left front of the listener 30, and the right front disposed at the right front. It generates and outputs a signal FR to the speaker SPFR, a signal RL to the left rear speaker SPRL arranged at the left rear, and a signal RR to the right rear speaker SPRR arranged at the right rear.

Here, the configuration of the sound field adjusting device of the present invention incorporated in the surround circuit 10 in the four-speaker surround system configured as described above belongs to the first to sixth embodiments and this embodiment. This will be described based on examples. In the surround circuit 10 of the present invention described with reference to FIG. 2, a difference signal (LR) is generated from the input left channel signal L and the right channel signal R, and two input signals L, R are generated. Based on the difference signal (LR), the driving signals FL and FR of the two front speakers SPFL and SPFR arranged in front of the listener 30 and the two rear speakers SPRL and SPRR arranged in the rear of the listener Although there is the same surround signal processing circuit 3 as the conventional example having a function of generating the drive signals RL and RR, the configuration of the surround signal processing circuit 3 is well known and will not be described here. The sound field adjusting device of the present invention is connected to the surround signal processing circuit 3.
(1) First Embodiment The first embodiment of the sound field adjusting device of the present invention is two rear speakers generated by the surround signal processing circuit 3 provided in the surround circuit 10 shown in FIG. In this embodiment, the drive signals RL and RR of SPRL and SPRR are mixed with part of the drive signals FL and FR of the two front speakers SPFL and SPFR, respectively.

  FIG. 3A shows the configuration of the first example of the first embodiment. In this embodiment, adders 12 are provided on the lines of drive signals RL and RR to the two rear speakers SPRL and SPRR, respectively. An amplifier 11R is installed on each line before the adder 12. The lines of the drive signals FL and FR to the two front speakers SPFL and SPFR are branched in the middle, and the branched lines are connected to the adder 12 via the amplifier 11F. The amplification factors of the amplifier 11F and the amplifier 11R may be fixed, but can be made variable according to the separation of the two-channel stereo signals L and R, as will be described later.

  In the first embodiment configured as described above, the signals flowing through the lines of the drive signals FL, FR of the two front speakers SPFL, SPFR on the lines of the drive signals RL, RR to the two rear speakers SPRL, SPRR. A part of is mixed. As a result, even if the drive signals RL and RR to the two rear speakers SPRL and SPRR become 0, the two rear speakers SPRL and SPRR have one of the drive signals FL and FR of the two front speakers SPFL and SPFR. Since the part flows, it is possible to prevent a problem that no sound is output from the two rear speakers SPRL and SPRR.

  FIG. 3B shows the configuration of the second example of the first embodiment. In this embodiment, a delay circuit is provided on the rear stage side of the adder 12 provided in the lines of the drive signals RL and RR to the two rear speakers SPRL and SPRR in the first embodiment described with reference to FIG. 13 are provided. The delay time set in the two delay circuits 13 may be the same. The delay circuit 13 causes a time delay in the sound output from the two rear speakers SPRL and SPRR, so that the listener can hear the sound coming from the front, and the sound has a sense of direction. According to the second embodiment, the conventional problems can be solved while maintaining the directionality of the sound from the front.

  FIG. 3C shows the configuration of the third example of the first embodiment. In this embodiment, delay circuits 13F are respectively provided between the branch points of the lines to the two front speakers SPFL and SPFR of the first embodiment described in FIG. 3A and the amplifier 11F. is there. The delay time set in the two delay circuits 13F may be the same. By the delay circuit 13F, a time delay occurs only in the mixed sound for the two front speakers SPFL and SPFR out of the sounds output from the two rear speakers SPRL and SPRR, so that the sound comes from the front. Hear and feel more direction. According to the third embodiment, in addition to the effects of the second embodiment, the directionality of sound from the front increases.

  FIG. 3D shows the configuration of the fourth example of the first embodiment. In this embodiment, in addition to the configuration of the third embodiment described with reference to FIG. 3C, a delay circuit 13R is also provided on the front side of the amplifier 11R provided in the line to the two rear speakers SPRL and SPRR. It is provided. The delay times set in the two types of delay circuits 13F and 13R may be the same, but can be different. By making the delay times set in the two types of delay circuits 13F and 13R different, the original sound from the two rear speakers SPRL and SPRR and the sound of the two mixed front speakers SPFL and SPFR are mixed. A time difference can be provided, and as a result, the fourth embodiment is easier to adjust the sound field than the third embodiment. For example, it is possible to give a sense of spread and a further direction to the sound emitted from the two rear speakers SPRL and SPRR.

FIG. 4A shows a configuration of a modification of the third example of the first embodiment. In this modification, the delay circuit 13F provided in the previous stage of the amplifier 11F in the third embodiment is moved between the amplifier 11F and the adder 12. The effect of this configuration is the same as that of the third embodiment. FIG. 4B shows a configuration of a first modification of the fourth example of the first embodiment, and FIG. 4C shows a fourth example of the fourth example of the first embodiment. 2 shows a configuration of a second modification. In the first modification, the delay circuit 13F provided on the front stage side of the amplifier 11F in the fourth embodiment is moved between the amplifier 11F and the adder 12. In the second modification, the delay circuit 13R provided on the front side of the amplifier 11R in the fourth embodiment is moved between the amplifier 11R and the adder 12. The effects of these configurations are the same as in the fourth embodiment.
(2) Second Embodiment The second embodiment of the sound field adjusting device of the present invention is that the sound field adjusting device of the first embodiment is connected to the two rear speakers SPRL and SPRR from the surround signal processing circuit 3. In this embodiment, a compression circuit 14 is provided in each drive signal line. The first to fourth examples of the second embodiment described here correspond to the configurations of the first to fourth examples of the first embodiment described above.

  Specifically, the compression circuit 14 in the second embodiment suppresses the dynamic range of signals such as a compressor circuit and a limiter circuit. Due to the action of the compression circuit 14, fluctuations in the magnitude of the sound output from the two rear speakers SPRL and SPRR are reduced. The effect of suppressing the fluctuation in the sound output from the two rear speakers SPRL and SPRR is further enhanced by mixing the sound output from the front speakers SPFL and SPFR with the sound output from the rear speakers SPRL and SPRR. Therefore, only the configuration of the following first to fourth examples of the second embodiment will be described here.

  FIG. 5A shows the configuration of the first example of the second embodiment. The configuration of this example corresponds to that of the first example of the first embodiment, and the difference is in the previous stage of the amplifier 11R provided in the lines of the drive signals RL and RR to the two rear speakers SPRL and SPRR. Only the compression circuit 14 is installed.

  FIG. 5B shows a configuration of a modification of the first example of the second embodiment. The modification of the first embodiment is different from the first embodiment only in the position of the compression circuit 14. That is, in the first embodiment, the compression circuit 14 is installed in front of the amplifier 11R provided in the lines of the drive signals RL and RR to the two rear speakers SPRL and SPRR. The circuit 14 is different from the first embodiment in that the circuit 14 is installed on the subsequent stage side of the adder 12.

  FIG. 6A shows the configuration of the second example of the second embodiment. The configuration of this example corresponds to the second example of the first embodiment, and the difference is in the previous stage of the amplifier 11R provided in the lines of the drive signals RL, RR to the two rear speakers SPRL, SPRR. Only the compression circuit 14 is installed.

  FIG. 6B shows the configuration of the third example of the second embodiment. The configuration of this example corresponds to the third example of the first embodiment, and the difference is in the previous stage of the amplifier 11R provided in the lines of the drive signals RL, RR to the two rear speakers SPRL, SPRR. Only the compression circuit 14 is installed.

  FIG. 6C shows the configuration of the fourth example of the second embodiment. The configuration of this example corresponds to the fourth example of the first embodiment. The difference is that the delay circuit 13R provided in the lines of the drive signals RL, RR to the two rear speakers SPRL, SPRR is different. The only point is that the compression circuits 14 are respectively installed in the preceding stage. The compression circuit 14 may be installed between the delay circuit 13R and the amplifier 11R.

  FIG. 7A shows a configuration of a modification of the second example of the second embodiment. In this modification, the compression circuit 14 provided on the upstream side of the amplifier 11R in the second embodiment is moved between the delay circuit 13 and the adder 12. FIG. 7B shows a configuration of a modification of the third example of the second embodiment. In this modification, the compression circuit 14 provided on the upstream side of the amplifier 11R in the third embodiment is moved to the downstream side of the adder 12. FIG. 7C shows a configuration of a modification of the fourth example of the second embodiment. In this modification, the compression circuit 14 provided on the front stage side of the delay circuit 13R in the fourth embodiment is moved to the rear stage side of the adder 12.

While various examples and modifications have been described above, the position of the compression circuit 14 installed in the drive signal line from the surround signal processing circuit 3 to the two rear speakers SPRL and SPRR in the second embodiment is particularly limited. Instead, it may be determined appropriately according to the magnitude of the output signal of the surround signal processing circuit 3.
(3) Third Embodiment In the third embodiment of the sound field adjusting device of the present invention, the surround signal processing is applied to the drive signals RL and RR of the two rear speakers SPRL and SPRR generated by the surround signal processing circuit 3. In this embodiment, a part of the two-channel stereo signals L and R to the circuit 3 are mixed.

  FIG. 8A shows the configuration of the first example of the third embodiment. In this embodiment, adders 12 are provided on the lines of drive signals RL and RR to the two rear speakers SPRL and SPRR, respectively. An amplifier 11R is installed on each line before the adder 12. The supply lines for the two-channel stereo signals L and R to the surround signal processing circuit 3 are branched in the middle, and the branched lines are connected to the adder 12 via the amplifier 11F. The amplification factors of the amplifier 11F and the amplifier 11R may be fixed, but can be made variable according to the separation of the two-channel stereo signals L and R, as will be described later.

  In the first example of the third embodiment configured as described above, the supply lines of the two-channel stereo signals L and R flow in the lines of the drive signals RL and RR to the two rear speakers SPRL and SPRR. Since some of the signals are mixed, even if the drive signals RL, RR to the two rear speakers SPRL, SPRR become 0, the two rear speakers SPRL, SPRR have two-channel stereo signals L, R. Since a part of the sound flows, it is possible to prevent a problem that no sound is output from the two rear speakers SPRL and SPRR.

  FIG. 8B shows the configuration of the second example of the third embodiment. In this embodiment, a delay circuit is provided on the rear stage side of the adder 12 provided in the lines of the drive signals RL and RR to the two rear speakers SPRL and SPRR of the first embodiment described with reference to FIG. 13 are provided. The delay time set in the two delay circuits 13 may be the same. The delay circuit 13 causes a time delay in the sound output from the two rear speakers SPRL and SPRR, so that the listener can hear the sound coming from the front, and the sound has a sense of direction. According to the second embodiment, the conventional problems can be solved while maintaining the directionality of the sound from the front.

  FIG. 8C shows the configuration of the third example of the third embodiment. In this embodiment, a delay circuit 13F is provided between the branch point of the supply line of the two-channel stereo signals L and R of the first embodiment described in FIG. 8A and the amplifier 11F. is there. The delay time set in the two delay circuits 13F may be the same. The delay circuit 13F allows the listener to hear the sound from the front so that only the mixed two-channel stereo signals L and R out of the sound output from the two rear speakers SPRL and SPRR are delayed. Gives a sense of direction. That is, according to the third embodiment, in addition to the effects of the second embodiment, the directionality of sound from the front increases.

  FIG. 8D shows the configuration of the fourth example of the third embodiment. In this embodiment, in addition to the configuration of the third embodiment described with reference to FIG. 8C, a delay circuit 13R is also provided on the front side of the amplifier 11R provided in the line to the two rear speakers SPRL and SPRR. It is provided. The delay times set in the two types of delay circuits 13F and 13R may be the same, but can be different. By making the delay times set in the two types of delay circuits 13F and 13R different, the original sound output from the two rear speakers SPRL and SPRR and the sound generated by the mixed two-channel stereo signals L and R can be reduced. A time difference can be provided, and as a result, the fourth embodiment is easier to adjust the sound field than the third embodiment. For example, it is possible to give a sense of spread and a further direction to the sound emitted from the two rear speakers SPRL and SPRR.

FIG. 9A shows a configuration of a modification of the third example of the third embodiment. In this modification, the delay circuit 13F provided in the previous stage of the amplifier 11F in the third embodiment is moved between the amplifier 11F and the adder 12. The effect of this configuration is the same as that of the third embodiment. FIG. 9B shows a configuration of a first modification of the fourth example of the third embodiment, and FIG. 9C shows a fourth example of the third embodiment. The structure of the 2nd modification of this is shown. In the first modification, the delay circuit 13F provided on the front stage side of the amplifier 11F in the fourth embodiment is moved between the amplifier 11F and the adder 12. In the second modification, the delay circuit 13R provided on the front side of the amplifier 11R in the fourth embodiment is moved between the amplifier 11R and the adder 12. The effects of these configurations are the same as in the fourth embodiment.
(4) Fourth Embodiment The fourth embodiment of the sound field adjusting device of the present invention is that the sound field adjusting device of the third embodiment is connected to the two rear speakers SPRL and SPRR from the surround signal processing circuit 3. In this embodiment, a compression circuit 14 is provided in each drive signal line. The first to fourth examples of the fourth embodiment described here correspond to the configurations of the first to fourth examples of the third embodiment described above.

  Specifically, the compression circuit 14 in the fourth embodiment suppresses the dynamic range of signals such as a compressor circuit and a limiter circuit. Due to the action of the compression circuit 14, fluctuations in the magnitude of the sound output from the two rear speakers SPRL and SPRR are reduced. The effect of suppressing the fluctuation in the sound output from the two rear speakers SPRL and SPRR is further enhanced by mixing the two-channel stereo signals L and R with the drive signals RL and RR of the rear speakers SPRL and SPRR. Accordingly, in the following first to fourth examples of the fourth embodiment, only the configuration will be described here.

  FIG. 10A shows the configuration of the first example of the fourth embodiment. The configuration of this example corresponds to that of the first example of the third embodiment, and the difference is in the previous stage of the amplifier 11R provided in the lines of the drive signals RL, RR to the two rear speakers SPRL, SPRR. Only the compression circuit 14 is installed.

  FIG. 10B shows a configuration of a modification of the first example of the fourth embodiment. The modification of the first embodiment is different from the first embodiment only in the position of the compression circuit 14. That is, in the first embodiment, the compression circuit 14 is installed in front of the amplifier 11R provided in the lines of the drive signals RL and RR to the two rear speakers SPRL and SPRR. The circuit 14 is different from the first embodiment in that the circuit 14 is installed on the subsequent stage side of the adder 12.

  FIG. 11A shows the configuration of the second example of the fourth embodiment. The configuration of this example corresponds to the second example of the third embodiment, and the difference is in the previous stage of the amplifier 11R provided in the lines of the drive signals RL, RR to the two rear speakers SPRL, SPRR. Only the compression circuit 14 is installed.

  FIG. 11B shows the configuration of the third example of the fourth embodiment. The configuration of this example corresponds to the third example of the third embodiment, and the difference is in the previous stage of the amplifier 11R provided in the lines of the drive signals RL, RR to the two rear speakers SPRL, SPRR. Only the compression circuit 14 is installed.

  FIG. 11C shows the configuration of the fourth example of the fourth embodiment. The configuration of this example corresponds to the fourth example of the third embodiment, and the difference is in the delay circuit 13R provided in the lines of the drive signals RL and RR to the two rear speakers SPRL and SPRR. The only point is that the compression circuits 14 are respectively installed in the preceding stage. The compression circuit 14 may be installed between the delay circuit 13R and the amplifier 11R.

  FIG. 12A shows a configuration of a modification of the second example of the fourth embodiment. In this modification, the compression circuit 14 provided on the upstream side of the amplifier 11R in the second embodiment is moved between the delay circuit 13 and the adder 12. FIG. 12B shows a configuration of a modification of the third example of the fourth embodiment. In this modification, the compression circuit 14 provided on the upstream side of the amplifier 11R in the third embodiment is moved to the downstream side of the adder 12. FIG. 12C shows a configuration of a modified example of the fourth example of the fourth embodiment. In this modification, the compression circuit 14 provided on the front stage side of the delay circuit 13R in the fourth embodiment is moved to the rear stage side of the adder 12.

Although various examples and modifications have been described above, the position of the compression circuit 14 installed in the drive signal line from the surround signal processing circuit 3 to the two rear speakers SPRL and SPRR in the fourth embodiment is particularly limited. Instead, it may be determined appropriately according to the magnitude of the output signal of the surround signal processing circuit 3.
(5) Fifth Embodiment In the fifth embodiment of the sound field adjusting device of the present invention, two front speakers SPRL, SPRR generated by the surround signal processing circuit 3 are supplied with two front signals. In this embodiment, a part of drive signals FL and FR of the speakers SPFL and SPFR are added by an adder 12F and then branched and mixed. In other words, the drive signals RL and RR of the two rear speakers SPRL and SPRR are added to the drive signals FL and FR of the two front speakers SPFL and SPFR to add a part of the monaural signal.

  In the fifth embodiment, in order to add a part of the monaural signal by adding the drive signals FL and FR of the two front speakers SPFL and SPFR to the drive signals RL and RR of the two rear speakers SPRL and SPRR, Although the separation of the sound output from the speakers SPRL and SPRR is deteriorated, there is an advantage that the sound is stably reproduced from the rear. In the fifth embodiment, the same example as that of the first embodiment, except that the signal is branched after adding the drive signals FL and FR of the two front speakers SPFL and SPFR, and the same. Variations are possible.

  Therefore, in the fifth embodiment, only basic configurations of the first to fourth examples and one modification corresponding to the first to fourth examples of the first embodiment will be described. stop.

  FIG. 13A shows the configuration of the first example of the fifth embodiment. In this embodiment, adders 12 are provided on the lines of drive signals RL and RR to the two rear speakers SPRL and SPRR, respectively. An amplifier 11R is installed on each line before the adder 12. The lines of the drive signals FL, FR to the two front speakers SPFL, SPFR are branched in the middle, and the branched lines are connected to the adder 12F via the amplifier 11F. The output of the adder 12F is branched into two and connected to the adder 12, respectively. Only one amplifier 11F may be provided after the adder 12F.

  FIG. 13B shows the configuration of the second example of the fifth embodiment. In this embodiment, a delay circuit is provided on the rear stage side of the adder 12 provided in the lines of the drive signals RL and RR to the two rear speakers SPRL and SPRR of the first embodiment described with reference to FIG. 13 are provided.

  FIG. 13C shows the configuration of the third example of the fifth embodiment. In this embodiment, one delay circuit 13F is provided after the adder 12F of the first embodiment described with reference to FIG.

  FIG. 13D shows the configuration of the fourth example of the fifth embodiment. In this embodiment, in addition to the configuration of the third embodiment described with reference to FIG. 13C, a delay circuit 13R is also provided on the front stage side of the amplifier 11R provided in the line to the two rear speakers SPRL and SPRR. It is provided.

Further, in the fifth embodiment, as in the second embodiment, an example in which a compression circuit 14 is provided in each of drive signal lines from the surround signal processing circuit 3 to the two rear speakers SPRL and SPRR is also possible. It is.
(6) Sixth Embodiment In the sixth embodiment of the sound field adjusting device of the present invention, the surround signal processing is applied to the drive signals RL, RR of the two rear speakers SPRL, SPRR generated by the surround signal processing circuit 3. In this embodiment, a part of the two-channel stereo signals L and R to the circuit 3 are added by an adder 12F and then branched and mixed. That is, a part of the monaural signal obtained by adding the two-channel stereo signals L and R to the drive signals RL and RR of the two rear speakers SPRL and SPRR is added.

  Also in the sixth embodiment, in order to add a part of the two rear speakers SPRL, SPRR drive signals RL, RR added to the monophonic signal by adding the two-channel stereo signals L, R, the signals are output from the rear speakers SPRL, SPRR. Although sound separation deteriorates, there is an advantage that sound is reproduced stably from the rear. In the sixth embodiment, the same example as that of the third embodiment and its modification are possible, except that the two-channel stereo signals L and R are added to make the signal monaural and then branched. .

  Therefore, in the sixth embodiment, only basic configurations of the first to fourth examples and one modification corresponding to the first to fourth examples of the third embodiment will be described. stop.

  FIG. 14A shows the configuration of the first example of the sixth embodiment. In this embodiment, adders 12 are provided on the lines of drive signals RL and RR to the two rear speakers SPRL and SPRR, respectively. An amplifier 11R is installed on each line before the adder 12. The supply lines for the two-channel stereo signals L and R are branched in the middle, and the branched lines are connected to the adder 12F via the amplifier 11F. The output of the adder 12F is branched into two and connected to the adder 12, respectively. Only one amplifier 11F may be provided after the adder 12F.

  FIG. 14B shows the configuration of the second example of the sixth embodiment. In this embodiment, a delay circuit is provided on the subsequent stage side of the adder 12 provided in the lines of the drive signals RL and RR to the two rear speakers SPRL and SPRR of the first embodiment described with reference to FIG. 13 are provided.

  FIG. 14C shows the configuration of the third example of the sixth embodiment. In this embodiment, one delay circuit 13F is provided after the adder 12F of the first embodiment described with reference to FIG.

  FIG. 14D shows the configuration of the fourth example of the sixth embodiment. In this embodiment, in addition to the configuration of the third embodiment described with reference to FIG. 14C, a delay circuit 13R is also provided on the front stage side of the amplifier 11R provided in the line to the two rear speakers SPRL and SPRR. It is provided.

  Further, in the sixth embodiment, as in the fourth embodiment, a configuration in which the compression circuit 14 is provided in each of the drive signal lines from the surround signal processing circuit 3 to the two rear speakers SPRL and SPRR is also possible. is there.

  FIG. 15A is a circuit diagram showing a configuration of one modification of the first example of the fifth embodiment. In the first example of the fifth embodiment, a part of the monaural signal obtained by adding the drive signals FL and FR of the two front speakers SPFL and SPFR to the drive signals RL and RR of the two rear speakers SPRL and SPRR. However, this modification is different in that one part of the drive signals FL and FR of the two front speakers SPFL and SPFR is added. In this modification, a part of the driving signal FL of the front speaker SPFL is added, but the driving signal FR of the front speaker SPFR may be added.

FIG. 15B is a circuit diagram showing a configuration of one modification of the first example of the sixth embodiment. In the first example of the sixth embodiment, a part of the monaural signal obtained by adding the two-channel stereo signals L and R to the driving signals RL and RR of the two rear speakers SPRL and SPRR is added. This modification is different in that a part of one of the two-channel stereo signals L and R is added. In this modification, a part of the driving signal FR of the front speaker SPFR is added, but the driving signal FL of the front speaker SPFL may be added.
(7) Amplifier gain adjustment in the first to sixth embodiments The amplifier 11F and the amplifier 11R are used in the first to sixth embodiments of the sound field adjusting apparatus of the present invention described above, The gains (amplification factors) of these amplifiers can be fixed values set in advance or can be varied. The case of adjusting the amplification factors of the amplifiers 11F and 11R will be described by taking the circuit of the first example of the first embodiment as an example.

  FIG. 16A shows a state in which the amplification factor adjustment circuit 21 is provided in the circuit of the first example of the first embodiment. When the amplification factor adjustment circuit 21 receives the mixture ratio instruction signals GL and GR from the mixture ratio correction circuit 20 described in FIG. 2, the amplification factor of the amplifier 11F and the amplifier 11R is determined in accordance with the mixture ratio instruction signals GL and GR. Then, the amplification factors of the amplifier 11F and the amplifier 11R are controlled.

  The drive signals FL and FR of the two front speakers SPFL and SPFR mixed with the drive signals RL and RR of the two rear speakers SPRL and SPRR, or the ratio of the two-channel stereo signals L and R is the two-channel stereo signal L, When R separation is large, it may be small. Therefore, the microcomputer 9 shown in FIG. 2 stores, for example, data obtained by mapping the characteristics shown in FIG. 16B in the form of a common map or a map for each amplifier, and a two-channel stereo signal. When the separation between L and R is large, the drive signals FL and FR of the two front speakers SPFL and SPFR or the mixing ratio of the two-channel stereo signals L and R, that is, the amplification ratios of the amplifier 11F and the amplifier 11R are reduced. To control.

  A predetermined threshold is set for the separation value of the two-channel stereo signals L and R, and when the separation of the input two-channel stereo signals L and R is larger than the threshold, the two front speakers SPFL and SPFR are set. It is also possible to control so that the drive signal FL, FR, or the mixing ratio of the two-channel stereo signals L, R, that is, the amplification ratio of the amplifier 11F and the amplifier 11R becomes small.

  By such control, when the separation of the two-channel stereo signal is large, the surround effect is exhibited, and when the separation is small, the problem that no sound is output from the rear speaker can be eliminated.

Furthermore, the addition amount of other signals added to the drive signal to the rear speaker is controlled by the type of the input source to the surround circuit 10 for the two-channel stereo signals L and R, which are switched by the changeover switch 7 described in FIG. You may make it do. For example, in a player system that reproduces a stereo signal from a recording medium such as a CD, MD, cassette, DVD, hard disk, and semiconductor memory, the separation of the stereo signal to be reproduced does not vary, and in a tuner system that receives radio waves, it depends on the reception environment. Since the separation of the stereo signal to be reproduced varies, the tuner system is controlled to increase the amount of other signals added to the drive signal to the rear speaker, and the player system is added to the drive signal to the rear speaker. It may be controlled so that the amount of addition of other signals to be reduced.
(8) Seventh Embodiment In the first to sixth embodiments of the sound field adjusting device of the present invention described above, the left front speaker SPFL disposed on the left front side of the listener 30 and the right front speaker SPFL are disposed on the right front side. The sound field adjusting device of the present invention was applied to a surround system using four speakers: a right front speaker SPFR, a left rear speaker SPRL arranged at the left rear, and a right rear speaker SPRR arranged at the right rear. .

  On the other hand, in the seventh embodiment of the sound field adjusting device of the present invention, as shown in FIG. 17A, the left front speaker SPFL arranged at the left front of the listener 30 and the right front arranged at the right front. The sound field adjusting apparatus of the present invention is applied to a surround system that uses three speakers: a speaker SPFR and a rear speaker SPRC arranged only one rear. In the seventh embodiment, the drive signal RC of the rear speaker SPRC generated by the surround signal processing circuit 3 is part of the drive signals FL and FR of the two front speakers SPFL and SPFR, or the two-channel stereo signals L and R. A portion of is added after mixing.

  FIG. 17B is a circuit diagram showing a configuration of one example in the seventh embodiment, and corresponds to the first example of the first embodiment. In this embodiment, an adder 12 is provided in the line of the drive signal RC to the rear speaker SPRC. An amplifier 11R is installed on the line before the adder 12. The lines of the drive signals FL and FR to the two front speakers SPFL and SPFR are branched in the middle, and the branched lines are connected to the adder 12F via the amplifier 11F and then connected to the adder 12. ing.

  In addition to this example, the following example is possible for the seventh embodiment.

  (A) A delay circuit is provided before or after the adder 12.

  (B) A delay circuit is provided before or after the amplifier 11F.

  (C) A delay circuit is provided before or after each of the amplifiers 11F and 11R.

  (D) A compression circuit is provided in the drive signal line to the rear speaker SPRC.

(E) One of the driving signals FL and FR of the two front speakers SPFL and SPFR or one of the two-channel stereo signals L and R is added to the driving signal line to the rear speakers SPRL and SPRR. .
(9) Eighth Embodiment As shown in FIG. 18 (a), the eighth embodiment of the sound field adjusting device of the present invention has a left front speaker SPFL, a right front speaker SPFR, a left rear speaker SPRL, and a right speaker. The sound field adjusting device of the present invention is applied to a surround system using five speakers including a front center speaker SPFC arranged at the front center of the listener 30 in addition to the four speakers of the rear speaker SPRR. In the eighth embodiment, the drive signals RL and RR of the two rear speakers SPRL and SPRR generated by the surround signal processing circuit 3, a part of the drive signals FL and FR of the two front speakers SPFL and SPFR, or 2 There is a first form in which a part of the channel stereo signals L and R is added and a second form in which a part of the drive signal FC of the front center speaker SPFC is added.

  FIG. 18B shows a first example of the first mode, in which only the drive signal FC of the center speaker SPFC at the front center is increased from the surround signal processing circuit 3, and the remaining configuration is shown in FIG. The configuration is the same as that of the first embodiment of the first mode described in (1), and the description thereof is omitted. FIG. 18C shows a second embodiment of the second mode. The adder 12 provided in the lines of the drive signals RL and RR to the two rear speakers SPRL and SPRC is connected to the front center speaker SPFC. A part of the signal FC is added after being amplified by the amplifier 11F.

  In addition to this example, the following example is possible in the eighth embodiment.

  (A) A delay circuit is provided before or after the adder 12.

  (B) A delay circuit is provided before or after the amplifier 11F.

  (C) A delay circuit is provided before or after each of the amplifiers 11F and 11R.

  (D) A compression circuit is provided for each of drive signal lines to the rear speakers SPRL and SPRR.

  (E) After mixing the drive signals FL and FR of the two front speakers SPFL and SPFR, or after mixing the two-channel stereo signals L and R, the rear speakers SPRL and SPRR respectively. To the drive signal line to

(F) One part of the driving signals FL and FR of the two front speakers SPFL and SPFR or one part of the two-channel stereo signals L and R are respectively on the driving signal lines to the rear speakers SPRL and SPRR. Added.
(10) Ninth Embodiment As shown in FIG. 19A, the ninth embodiment of the sound field adjusting device of the present invention includes a left front speaker SPFL, a right front speaker SPFR, a left rear speaker SPRL, and a right speaker. The sound field adjusting device of the present invention is applied to a surround system using six speakers including a front center speaker SPFC and a rear center speaker SPRC in addition to the four speakers of the rear speaker SPRR.

  In the ninth embodiment, the following four examples can be considered depending on what signals are mixed in the rear center speaker SPRC.

  In the first embodiment, a part of the drive signal FC to the front center speaker SPFC is mixed with the rear center speaker SPRC, and this configuration is shown in FIG. 19B. Since other configurations are the same as those of the first example of the first embodiment, the description thereof is omitted.

  In the second embodiment, a part of the drive signal FC to the front center speaker SPFC is mixed with all the three rear speakers SPRL, SPRC, SPRR, and this configuration is shown in FIG. 19 (c). .

  In the third embodiment, a part of the drive signals FL and FR to the left front speaker SPFL and the right front speaker SPFR are added to the rear center speaker SPRC, and this configuration is added to FIG. 20 (a). Indicated.

  In the fourth embodiment, the drive signal RC to the rear center speaker SPRC is mixed with the drive signal to the left rear speaker SPRL after a part of the drive signal FL to the left front speaker SPFL is mixed, and the right front speaker SPFR. The drive signal to the right rear speaker SPRR after a part of the drive signal FR to is added to the adder 12C through the amplifier circuit 11C, and this configuration is shown in FIG. It is.

  In the ninth embodiment, as in the eighth example, examples of the configurations (A) to (F) described above are possible.

  Note that the sound field adjustment device of the present invention configured as described above is connected to a surround device equipped with an FM tuner when the vehicle is driven in an area where the radio wave condition is poor. It is particularly effective.

  If the sound field adjusting device of the present invention is connected to a surround device that generates a 4-channel surround signal based on a stereo 2-channel signal or a difference component thereof, the separation of the stereo 2-channel signal input to the surround device is caused for some reason. Even if it deteriorates, there are no problems such as fluctuations in the size of the incoming sound from the rear and no inconvenience that no sound is produced, so that the sound field adjusting device can be used effectively. In particular, the present invention is effective when applied to a sound field adjusting device that adjusts sound output from a surround device mounted on an automobile.

(A) is a diagram showing the operation of the surround processing circuit when an FM tuner is installed in a strong electric field area, and (b) is a problem of the operation of the surround processing circuit when an FM tuner is installed in a weak electric field area. It is a figure which shows a point. 1 is an overall configuration diagram of an audio system including a surround circuit that incorporates a sound field adjusting device of the present invention. 1 shows a first embodiment when a sound field adjusting device of the present invention is connected to a surround device of a four-speaker system, and (a) is a circuit diagram showing a configuration of a first example of the first embodiment. (B) is a circuit diagram showing the configuration of the second example of the first embodiment, (c) is a circuit diagram showing the configuration of the third example of the first embodiment, (d) is the first diagram It is a circuit diagram which shows the structure of the 4th Example of 1 embodiment. (A) is a circuit diagram showing the configuration of a modification of the third example of the first embodiment, (b) shows the configuration of the first modification of the fourth example of the first embodiment. A circuit diagram and (c) are circuit diagrams showing the composition of the 2nd modification of the 4th example of a 1st embodiment. The 2nd Embodiment at the time of connecting the sound field adjustment apparatus of this invention to the surround apparatus of 4 speaker system is shown, (a) is a circuit diagram which shows the structure of the 1st Example of 2nd Embodiment. (B) is a circuit diagram which shows the structure of the modification of the 1st Example of 2nd Embodiment. (A) is a circuit diagram showing a configuration of a second example of the second embodiment, (b) is a circuit diagram showing a configuration of a third example of the second embodiment, and (c) is a second diagram. It is a circuit diagram which shows the structure of the 4th Example of this embodiment. (A) is a circuit diagram showing a configuration of a modification of the second example of the second embodiment, (b) is a circuit diagram showing a configuration of a modification of the third example of the second embodiment, (C) is a circuit diagram showing a configuration of a fourth example of the second embodiment. The third embodiment at the time of connecting the sound field adjusting device of the present invention to the surround device of the four speaker system is shown, and (a) is a circuit diagram showing the configuration of the first example of the third embodiment. (B) is a circuit diagram showing a configuration of a second example of the third embodiment, (c) is a circuit diagram showing a configuration of a third example of the third embodiment, and (d) is a circuit diagram showing the configuration of the third example. It is a circuit diagram which shows the structure of the 4th Example of 3 embodiment. (A) is a circuit diagram showing the configuration of a modification of the third example of the third embodiment, (b) shows the configuration of the first modification of the fourth example of the third embodiment. A circuit diagram and (c) are circuit diagrams showing the composition of the 2nd modification of the 4th example of a 3rd embodiment. The 4th Embodiment at the time of connecting the sound field adjustment apparatus of this invention to the surround apparatus of 4 speaker system is shown, (a) is a circuit diagram which shows the structure of the 1st Example of 4th Embodiment. (B) is a circuit diagram which shows the structure of the modification of the 1st Example of 4th Embodiment. (A) is a circuit diagram showing a configuration of a second example of the fourth embodiment, (b) is a circuit diagram showing a configuration of a third example of the fourth embodiment, and (c) is a fourth diagram. It is a circuit diagram which shows the structure of the 4th Example of this embodiment. (A) is a circuit diagram showing a configuration of a modification of the second example of the fourth embodiment, (b) is a circuit diagram showing a configuration of a modification of the third example of the fourth embodiment, (C) is a circuit diagram which shows the structure of the 4th Example of 4th Embodiment. The 5th Embodiment at the time of connecting the sound field adjustment apparatus of this invention to the surround apparatus of 4 speaker system is shown, (a) is a circuit diagram which shows the structure of the 1st Example of 5th Embodiment. , (B) is a circuit diagram showing a configuration of a second example of the fifth embodiment, (c) is a circuit diagram showing a configuration of a third example of the fifth embodiment, and (d) is a circuit diagram showing the configuration of the third example. It is a circuit diagram which shows the structure of the 4th Example of 5 embodiment. The 6th Embodiment at the time of connecting the sound field adjustment apparatus of this invention to the surround apparatus of 4 speaker system is shown, (a) is a circuit diagram which shows the structure of the 1st Example of 6th Embodiment. , (B) is a circuit diagram showing a configuration of a second example of the sixth embodiment, (c) is a circuit diagram showing a configuration of a third example of the sixth embodiment, and (d) is a circuit diagram showing the configuration of the third example. It is a circuit diagram which shows the structure of the 4th Example of 6 embodiment. (A) is a circuit diagram which shows the structure of the modification of the 1st Example of 5th Embodiment, (b) is a circuit diagram which shows the structure of the modification of the 1st Example of 6th Embodiment. is there. (A) is a circuit diagram showing a circuit configuration for adjusting the amplification factor of the amplifier provided in the circuit of the embodiment described above, and (b) explains the characteristics of the separation of the two-channel stereo signal and the gain characteristics of each amplifier. It is a typical characteristic figure. (A) is a figure which shows the example of arrangement | positioning of each speaker in 7th Embodiment which incorporated the sound field adjustment apparatus of this invention in the surround circuit of the surround apparatus of 3 speaker system, (b) is in 7th Embodiment. It is a circuit diagram which shows the structure of one Example. (A) is a figure which shows the example of arrangement | positioning of each speaker in 8th Embodiment which incorporated the sound field adjustment apparatus of this invention in the surround circuit of the surround apparatus of 5 speaker system, (b) is in 8th Embodiment. The circuit diagram which shows the structure of a 1st Example, (c) is a circuit diagram which shows the structure of the 2nd Example in 8th Embodiment. (A) is a figure which shows the example of arrangement | positioning of each speaker in 9th Embodiment which incorporated the sound field adjustment apparatus of this invention in the surround circuit of the surround apparatus of 6 speaker system, (b) is in 9th Embodiment. The circuit diagram which shows the structure of a 1st Example, (c) is a circuit diagram which shows the structure of the 2nd Example in 9th Embodiment. (A) is a circuit diagram showing a configuration of a third example in the ninth embodiment, and (b) is a circuit diagram showing a configuration of a fourth example in the ninth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Antenna 2 ... FM tuner 3 ... Surround signal processing circuit 7 ... Changeover switch 8 ... Operation device selector 9 ... Microcomputer 10 ... Surround circuit 11, 11F, 11R of this invention ... Amplifier 12, 12C, 12F ... Adder 13, 13F, 13R ... delay circuit 14 ... compression circuit 20 ... mixing rate correction circuit 21 ... gain adjustment circuit 30 ... listener SPFC ... front center speaker SPFL ... left front speaker SPFR ... right front speaker SPRC ... rear center speaker SPRL ... left rear Speaker SPRR: Right rear speaker

Claims (20)

Surround signal processing means for generating a surround signal based on a left channel signal and a right channel signal input from a playback device that outputs a two-channel stereo signal, and a difference signal generated from these input signals, The channel stereo signal is a sound field adjustment device connected to a surround device that is a reception signal whose separation varies depending on reception conditions.
From the surround signal processing means, as the surround signal, surround signals for at least two left and right forward incoming sounds coming from the front of the listener, and at least one back incoming sound surround coming from the rear of the listener Signal is output,
The sound field adjusting device includes an adder on a line to which the surround signal for the backward incoming sound is input, and a part of the surround signal for the forward incoming sound is led to the adder as an added signal, A sound field adjusting device, wherein the sound field adjusting device is added to the surround signal for the backward incoming sound. Surround signal processing means for generating a surround signal based on a left channel signal and a right channel signal input from a playback device that outputs a two-channel stereo signal, and a difference signal generated from these input signals, The channel stereo signal is a sound field adjustment device connected to a surround device that is a reception signal whose separation varies depending on reception conditions.
From the surround signal processing means, as the surround signal, surround signals for at least two left and right forward incoming sounds coming from the front of the listener, and at least one back incoming sound surround coming from the rear of the listener Signal is output,
The sound field adjusting means includes an adder on a line to which the surround signal for the backward incoming sound is input, and a part of the left channel signal or the right channel signal is supplied to the adder as the addition signal. A sound field adjusting device that is guided and added to the surround signal for the backward incoming sound. The sound field adjusting device according to claim 1 or 2,
The sound field adjusting apparatus according to claim 1, wherein the received signal is a two-channel stereo signal demodulated by receiving FM radio waves. The sound field adjusting device according to any one of claims 1 to 3,
The sound field adjusting means includes two lines to which the left and right surround sound signals for the forward incoming sound output from the surround signal processing means are respectively input, and two left and right rear signals output from the surround signal processing means. 2. A sound field adjusting apparatus comprising two lines to which incoming sound surround signals are respectively input. The sound field adjusting device according to claim 4,
The adder provided on the left rear incoming surround signal line has a part of the left front incoming surround signal or a part of the left channel signal as the addition signal. The adder provided in the right rear incoming sound surround signal line is connected to a part of the right front incoming surround signal or a part of the right channel signal. A sound field adjusting device characterized by being guided as an addition signal. The sound field adjusting device according to claim 4,
In the adder provided in the left and right rear arriving sound surround signal lines, a sum of a part of the left and right front arriving sound surround signals, or a sum of a part of the left and right channel signals, A sound field adjusting device, wherein the sound field adjusting device is guided as the addition signal. The sound field adjusting device according to claim 4,
In the adder provided in the left and right rear incoming sound surround signal lines, one part of the left and right front incoming sound surround signals, or one part of the left and right channel signals, A sound field adjusting device, wherein the sound field adjusting device is guided as the addition signal. The sound field adjustment device according to any one of claims 1 to 4,
The sound field adjusting means includes a central line output from the surround signal processing means in addition to two lines to which the left and right front incoming sound surround signals output from the surround signal processing means are respectively input. There is a line to which the surround signal for the forward incoming sound is input,
The sound field adjusting apparatus according to claim 1, wherein a part of the center front incoming sound surround signal is guided to the adder provided in the rear incoming sound surround signal line as the added signal. The sound field adjusting device according to claim 5,
The sound field adjusting means further includes a line for inputting a surround signal for a central forward incoming sound and a line for inputting a surround signal for a central backward incoming sound, which are output from the surround signal processing means. Provided,
Sound field adjustment characterized in that a part of the center front arriving sound surround signal is guided as the sum signal to the adder provided in the center arriving sound surround signal line. apparatus. The sound field adjustment device according to claim 8,
The sound signal adjusting device characterized in that the line of the surround signal for the backward arriving sound is three lines to which the two surround signals for the backward arriving sound and the surround signal for the central backward arriving sound are input. . The sound field adjusting device according to claim 5,
The sound field adjustment means is further provided with a line for inputting a surround signal for the central rear incoming sound output from the surround signal processing means,
A sum of a part of the left and right front arriving sound surround signals is guided to the adder provided in the center rear arriving sound surround signal line as the added signal. Field adjustment device. The sound field adjusting device according to claim 5,
The sound field adjustment means is further provided with a line for inputting a surround signal for the central rear incoming sound output from the surround signal processing means,
In the adder provided in the center signal line for the backward incoming sound, a part of the output signal of the adder provided in the left signal line for the backward incoming sound, and The sound field adjusting apparatus according to claim 1, wherein a part of the output signal of the adder provided in the right rear surround sound signal line is led as the addition signal. The sound field adjusting device according to any one of claims 1 to 12,
An apparatus for adjusting a sound field, wherein an amplifier is provided in each line connected to an input side of the adder provided in the sound field adjusting means. The sound field adjusting device according to any one of claims 1 to 13,
A delay circuit is provided on a line connected to the output side of the adder provided in the sound field adjusting means, and the surround signal for the backward incoming sound after the addition is delayed for a predetermined time by the delay circuit. A sound field adjusting device characterized by that. The sound field adjusting device according to any one of claims 1 to 13,
A first delay circuit is provided in a line of the addition signal connected to an input side of the adder provided in the sound field adjusting means;
A part of the surround signal for the left and right front incoming sounds or a part of the signal for the left and right channel is delayed by a predetermined time by the first delay circuit before addition to the surround signal for the rear incoming sound. A sound field adjusting device characterized by that. The sound field adjusting device according to claim 15,
A second delay circuit is provided in a line of the surround signal for the backward incoming sound connected to the input side of the adder provided in the sound field adjusting means;
The sound field adjusting apparatus according to claim 1, wherein the surround signal for the backward arriving sound output from the surround signal processing means is delayed for a predetermined time by the second delay circuit before the adder. The sound field adjusting device according to claim 13,
The amplification factor adjusting means of the amplifier is provided in the sound field adjusting means,
The amplification factor of the amplifier is adjusted by the amplification factor adjustment unit according to the type of input source when the source type of the two-channel stereo signal and the separation of the source are known. Field adjustment device. The sound field adjusting device according to any one of claims 1 to 17 ,
The sound field adjusting device is connected to a surround circuit of an in-vehicle acoustic device having at least one of an AM tuner, an FM tuner, and a TV tuner as a source of the two-channel stereo signal. Field adjustment device. A surround circuit to which the sound field adjusting device according to claim 18 is connected,
The surround circuit, wherein the surround signal output from the surround circuit is a signal for driving at least three speakers provided in the in-vehicle acoustic device. An on-vehicle acoustic device comprising the surround circuit according to claim 19 ,
There are a plurality of types of playback devices that output the two-channel stereo signal, and there is provided means for selecting one of the playback devices, and depending on the type of the selected playback device, it is added to the surround signal for the backward incoming sound. An in-vehicle acoustic device characterized in that an addition amount of the addition signal is controlled.

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