JPH03254300A - Sound field reproducing device - Google Patents

Abstract

PURPOSE:To adjust the sense of presence with the simple input operation of only an effect sound level and to improve the operability by adjusting strong/ weak presence depending on the effect sound level. CONSTITUTION:An effect sound signal generating means consists of effect sound signal arithmetic means 24, 25 realized by a digital signal processor 1 or the like and level change means 27, 28 arranged to the post stage of them. The effect sound signal arithmetic means 24, 25 applies arithmetic processing to a direct sound signal inputted from a direct sound signal generating source to generate an effect sound signal such as an initial reflected sound or an echo sound. The effect sound signal generated in this way is outputted to an effect sound speaker via the level change means 27, 28 and a level change of the level change means 27, 28 is controlled by a control means 7 and the control means 7 adjusts an output signal level of the level change means 27, 28 in response to a strong/weak level of the sense of presence set by an input operation means 6. Thus, strong/weak level of the presence is adjusted with a simple input operation of adjusting the effect sound level.

Description

[Detailed Description of the Invention] Overview In a sound field reproduction device that uses a so-called digital signal processor or the like to generate sound effects for reproducing a sound field with a sense of presence, the intensity of the sense of presence is determined by the sound effect level. Adjust by.

Thereby, the sense of presence can be adjusted by a simple input operation of only the sound effect level, without adjusting a large number of parameters for generating the sound effect signal, such as delay time.

INDUSTRIAL APPLICATION FIELD OF THE INVENTION The present invention relates to an Odaiba playback device that is suitably implemented as a vehicle-mounted sound playback device configured using a digital signal processor or the like.

Conventional technology In recent years, digital processing technology for audio signals has progressed, and sound field reproduction devices have been proposed that use so-called digital signal processors to create an optimal sound field depending on the type of music being played. . When this sound field reproducing device is used, for example, in a vehicle, speakers are arranged on the front left and right sides, the front center, and the rear left and right sides of the listening position.

Further, the digital signal processor generates the early reflected sound and the reverberant sound through calculation processing, and adds the generated sound to the direct sound and places it at each of the positions according to the sound field to be reproduced. sound from a speaker. In this way, the system is configured to reproduce sound with a sense of realism.

In typical conventional techniques, the intensity of the sense of presence is adjusted by changing a number of parameters for arithmetic processing within the digital signal processor. The parameters include, for example, an initial delay time from when the direct sound is emitted until the early reflected sound is emitted, and a reverberation time from when the direct sound is emitted until the reverberant sound disappears.

Problems to be Solved by the Invention In the above-mentioned conventional technology, there are many parameters to be set, and therefore complicated input operations are required.

For this reason, in the case of a vehicle-mounted sound reproducing device in which easy operation is desired, this is not preferable from the viewpoint of safe driving.

In addition, inside the vehicle, which is a relatively limited and narrow acoustic space,
The reverberant sound generated by the digital signal processor and the reverberant sound naturally generated by reflections from glass surfaces cancel each other out. can't get it.

An object of the present invention is to provide a sound field reproducing device that can adjust the strength of the sense of presence with a simple input operation.

Means for Solving the Problems The present invention provides a direct sound signal generation source that generates a direct sound signal, and a sound effect signal generation means, which includes: A sound effect signal calculation means for generating a sound effect signal for reproducing a sound field with a sense of feeling, and a level changing means for receiving the sound effect signal from the sound effect signal calculation means and changing the signal level. , such a sound effect signal generating means, a direct sound speaker for asonizing the direct sound signal from the direct sound signal generation source, and a sound effect speaker for asonizing the sound effect signal from the sound effect signal generating means. The present invention is characterized in that it includes a speaker, an input operation means for inputting and controlling the intensity of the sense of presence, and a control means for adjusting the output signal level of the level changing means in response to the output of the input operation means. It is a sound field reproduction device.

According to the present invention, a direct sound signal from a direct sound signal generation source such as a magnetic tape playback device or a radio receiver is applied to a direct sound speaker and converted into sound.

Further, the sound effect signal generated by the sound effect signal generation means based on the direct sound signal is given to a sound effect speaker and converted into sound. In this way, a realistic sound field is reproduced using the direct sound and sound effects.

The sound effect signal generation means includes a sound effect signal calculation means realized by a digital signal processor or the like, and a level change means arranged after the sound effect signal calculation means. The sound effect signal calculation means performs calculation processing on the direct sound signal input from the direct sound signal generation source, and generates sound effect signals such as early reflected sound and reverberant sound.

The sound effect signal generated in this way is output to the sound effect speaker via the level changing means. The amount of level change in the level change means is controlled by a control means, and the control means adjusts the output signal level of the level change means in accordance with the intensity level of the sense of presence set in the input operation means. .

Therefore, the intensity of the sense of presence can be adjusted by a simple input operation for adjusting the sound effect level.

Embodiment FIG. 1 is a block diagram showing the electrical configuration of a digital signal processor 1 used in a vehicle-mounted sound reproduction device 2 according to an embodiment of the present invention, and FIG. 2 is a block diagram showing the electrical configuration of the audio reproduction device 2. FIG. The acoustic signal source 3, which is a direct sound signal generation source and is realized by a magnetic tape playback device, a radio receiver, etc., outputs acoustic signals of both left and right channels. This acoustic signal is separated by the balance/fade adjustment section 4 into direct sound signals of front left and right, rear left and right, and the sum of both left and right channels.

The direct sound signal of the front left channel is applied to the speaker 5PFL via the power amplifier AFL and is converted into sound. Similarly, the direct sound signal of the front right channel is transmitted to the power amplifier AP
The signal is applied to the speaker 5PPR via R and converted into sound.

The direct sound signal, which is the sum of the left and right channels, is converted into a digital signal by an analog/digital converter 5 and input to a digital signal processor 1, which is a sound effect signal generating means. In connection with this digital signal processor 1, an input operation section 6, a control section 7, and a memory 8 are provided, and as will be described later, the digital signal processor 1 generates an early reflected sound based on the direct sound signal. Generate sound effect signals such as reverberation. The digital signal processor 1 outputs sound effect signals from the rear left and right and from the front center.

The sound effect signal of the rear left channel is converted into an analog sound signal by the digital/analog converter DARL, and the sound effect signal of the rear left channel is
After being added to the direct sound signal from the balance/fade adjustment unit 4 in the BRL, it is applied to the speaker 5PRL via the power amplifier ARL and converted into sound.

Similarly, the rear right channel sound effect signal is converted into an analog sound signal by a digital/analog converter DARR,
After being added with the direct sound signal in the adder BRR, it is applied to the speaker 5PRR via the power amplifier ARI''j and converted into sound. The signal is applied to the speaker 5PFC via the amplifier AFC and converted into sound.

In the vehicle interior 10 of the car, there is a speaker 5P on the front left side.
FL is arranged, a speaker 5PFR is arranged on the front right side, a speaker 5PFC is arranged on the front center, a speaker 5PRL is arranged on the rear left side, and a speaker 5PRR is arranged on the rear right side. center speaker 5
Sound from the PPC is reflected by the windshield 11 and radiated into the vehicle interior 10.

This sound reproduction device 2 is set to three operating modes, for example, high-fidelity, casual, and funky. These operation modes can be switched by operating the mode changeover switch 6a of the input operation section 6.

When the high-fidelity mode is selected, the digital signal processor 1 is turned off, and the direct sound signal of the sum of the left and right channels to the analog/digital converter 5 is directly input to the power amplifier AFC by a configuration not shown. be done. Also, at this time, the rear speakers 5PRL, 5P
Only direct sound is emitted from the RR.

In addition, when the casual mode is selected, the digital signal processor 1 is turned on, and there is almost no sound reflected from the floor, and a relatively long delay time is set, assuming a concert hall or the like where there is a lot of sound reflected from the walls and ceiling. Reverberation sound is added. Furthermore, when the funky mode is selected, reverberation sound with a relatively short delay time is added, assuming a live music venue or the like where there is a lot of sound reflected from the floor.

Referring to FIG. 1, in digital signal processor 1, data from analog/digital converter 5 is input to multiplier 21 from input terminal P1. The multiplier 21 multiplies the input data by a predetermined coefficient a and outputs the multiplied data to the filter circuit n22 in order to prevent data overflow during the arithmetic processing process described later. The filter circuit 22 is a low-pass filter for setting the sound quality of the sound effect, and converts the output from the multiplier 21 into r-waves at a predetermined cutoff frequency J.

The output from the filter circuit 22 is sent to effect adjustment circuits CRL and C provided for each of the rear left and right channels and the front center channel.
RR, CFC (hereinafter referred to collectively as reference mark C)
given to. The output of the filter circuit 22 is also given to an early reflected sound generation circuit 24, which generates early reflected sounds for each of the rear left and right and front center channels, and Output to adjustment circuit C. Furthermore, the output from the filter circuit 22 is given to a reverberation sound generation circuit 25, which generates reverberation sound for each channel of the rear left and right and front center channels, and generates the reverberation sound for each channel of the rear left and right and front center channels. Output to adjustment circuit C.

The early reflected sound generation circuit 24 and the reverberation sound generation circuit 25
constitutes a sound effect signal calculation means.

The effect adjustment circuit CRL includes four multipliers 26 to 29 and an addition circuit 30.

A multiplier 26 is applied to the direct sound signal from the filter circuit 22.
The early reflected sound signal from the early reflected sound generating circuit 24 is multiplied by the coefficient C in the multiplier 27, and the reverberant sound signal from the reverberant sound generating circuit 25 is multiplied by the coefficient d in the multiplier 28. Multiplyed. Multipliers 27 and 28 constitute level changing means. The outputs from each of the multipliers 26 to 28 are added in an adder circuit 30, multiplied by a coefficient e in a multiplier 29 to adjust the overall level, and then sent from the output terminal PRL to the digital/analog converter DARL. Output.

Note that the remaining effect adjustment circuits CRR and CFC are configured in the same manner as this effect adjustment circuit CRL.
The output from the effect adjustment circuit CFC is input to the digital/analog converter DARR via the output terminal PRR, and the output from the effect adjustment circuit CFC is input to the digital/analog converter DAFC via the output terminal RFC.

Coefficients a, bc, d, e of each of the multipliers 21.26 to 29
, and the cutoff frequency f of the filter circuit M@22 are set in accordance with the coefficient data input from the control unit 7 via the input/output port 31.

The coefficient data is switched by an input operation to the mode changeover switch 6a of the input operation section 6, and is individually set in advance for each of the operation modes.

In addition, the early reflected sound generation circuit 24 and the reverberation sound generation circuit 2
The calculation constant 5 is determined by the control unit 7 according to each operation mode.
Set by constant data from . The early reflected sound generation circuit 24 and the reverberation sound generation circuit 25 are connected to the control section 7.
The direct sound signal from the filter circuit 22 is processed based on the constant from the filter circuit 22, and the result of the calculation is repeatedly written to/read from the memory 8 via the register 32, thereby generating early reflected sound and reverberant sound. .

The input operation section 6 is also provided with a sense of presence changeover switch 6b for setting the strength of the sense of presence. The presence changeover switch 6b is realized by an up/down switch or the like, and when the switch 6b is operated, the coefficient C of the multiplier 27 provided after the early reflection sound generation circuit 24 and the reverberation sound generation circuit 25 are changed. The coefficient d of the multiplier 28 provided at the subsequent stage is changed stepwise.

FIG. 3 is a graph showing the structure of sound effects on the time axis. In FIG. 3, reference numeral M1 represents direct sound, reference numeral M2 represents early reflected sound, and reference numeral M3 represents reverberant sound. As mentioned above, the coefficients c, d of multipliers 27 and 28
For example, when changing It can be switched to a weakened state.

Note that if the coefficient e of the multiplier 29 is changed, the direct sound level will also change, causing the front-rear balance to collapse.

Therefore, as is clear from FIG. 3, the reverberation time T1 can be changed in a pseudo manner by changing the levels of the early reflected sound and the reverberant sound, which are sound effects.

Therefore, the sound effect level and reverberation time T
1 change together, the sense of presence changes greatly in the auditory sense, and the strength of the sense of presence can be adjusted effectively.

Further, the intensity of the sense of presence can be adjusted simply by changing the coefficients c and d of the multipliers 27 and 28 in response to the input operation of the sense of presence changeover switch 6b.
4 or the calculation constants in the reverberant sound generation circuit 25, the adjustment of the sense of presence can be completed in a short period of time, e.g., 172 to 1/3, compared to the case where a large number of parameters are changed, such as rewriting the calculation constants in the reverberation sound generation circuit 25. be able to. Furthermore, the intensity of the sense of presence can be easily adjusted by simply operating the sense of presence changeover switch 6b, thereby improving operability. Moreover, since it is such a simple operation, it can be suitably implemented in a vehicle-mounted sound reproduction device.

Effects of the Invention As described above, according to the present invention, the strength of the sense of presence is adjusted by the sound effect level, so there is no need to adjust many parameters such as the delay time for generating the sound effect signal. , the sense of presence can be adjusted with a simple input operation of only the sound effect level, and operability can be improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the electrical configuration of a digital signal processor 1 used in an audio reproduction device 2 according to an embodiment of the present invention, FIG. 2 is a block diagram showing the electrical configuration of the audio reproduction device 2, and FIG. The figure is a graph showing the structure of sound effects on the time axis to explain a method of adjusting the sense of presence. l Digital signal processor, 2. Sound reproduction device,
3...Acoustic signal source, 6...Input operation section, 6b81.
Realism changeover switch, 7...control unit, 21.26-2
9... Multiplier, 24... Early reflected sound generation circuit, 25...
・・Reverberation sound generation circuit, CRL, CRR, CFC-effect adjustment circuit, 5PFL, 5PPR, 5PFC3PRL, 5P
RR...Speaker

Claims (1)

[Scope of Claims] A direct sound signal generation source that generates a direct sound signal, and a sound effect signal generation means, which generates a realistic sound field in association with the direct sound signal from the direct sound signal generation source. a sound effect signal calculation means for generating a sound effect signal for reproducing the sound effect signal; a sound effect signal from the sound effect signal calculation means is input;
a level changing means for changing the signal level; a direct sound speaker for converting the direct sound signal from the direct sound signal generation source into sound; and the sound effect signal generating means. a sound effect speaker for converting a sound effect signal from a sound effect into sound; an input operation means for inputting and controlling the intensity of the sense of presence; and an input operation means for controlling the output signal level of the level changing means in response to the output of the input operation means. A sound field reproducing device comprising: a control means for adjusting.