JPH03143196A - Acoustic reproducing device - Google Patents

Abstract

PURPOSE:To obtain a sound field control effect and an illuminating effect synchronizing with the tempo and rhythm of a melody by calculating the auto- correlation function of an acoustic signal and controlling a sound field controller and an illuminator by the values of auto-correlation factors. CONSTITUTION:Values obtained through calculation in auto-correlation function calculating circuits 3-1,..., 3-n are correlation factors. They are converted into control signals for controlling an output signal 21 from an acoustic signal reproducing device 1 by auto-correlation factor converting circuits 4-1,..., 4-n to control a sound field controller 6. On the other hand, they are converted into signals for controlling an illuminator by auto-correlation factor converting circuits 5-1,..., 5-n to control an illuminator 7 with dimmer. Further, the output signal 21 from the acoustic signal reproducing device 1 and an output signal 30 from a sound field sensor respectively pass through low pass filters 9. The cut off frequency of the low pass filter 9 is set to about 100Hz. The signals passing through the respective filters enter a cross-correlation function calculating circuit 10 to calculate a cross-correlation function.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention controls the acoustic space in the listening room in synchronization with the acoustic signal in a space such as a listening room, improves the lighting effect, and prevents insufficient light in the listening room during playback. The present invention relates to a sound reproduction device that enhances acoustic effects by adding deep bass and correcting high frequencies.

Conventional Technology When listening to music in a general listening room, there are now more opportunities to enjoy both sound and video as audiovisual equipment has become more sophisticated. There are sound field control devices and lighting devices that further enhance this effect.

The conventional sound field control device has a sound field menu 1 as shown in FIG.
- The selection circuit 50 allows the user to set the menu in advance and control the signal from the audio signal reproduction device 1.

Further, a conventional method for controlling lighting effects in synchronization with an acoustic signal will be explained with reference to the drawings.

FIG. 9 shows a conventional sound reproduction device.

In FIG. 9, the output signal 2 from the audio signal reproducing device l
1 is divided into frequency bands by a band division filter. That is, low pass filter 53 pan 1 pass filter 54. The high-pass filter 55 divides the signal into three frequency bands. The band is the low range (20 to about 20
0112), medium range (approximately 200 to approximately 5Kt(Z)), high frequency range (approximately 5KIIZ to 20Kl+Z), and the power and to-off frequencies vary somewhat.

Each signal that has passed through each of the above filters is detected by a level detection circuit 56, 57, 58 to detect the input level for each band.Dimmer equipment lighting devices 59, 60, 61 are dimmed in accordance with the input level. The configuration is such that

Problems to be Solved by the Invention However, with the conventional configuration as described above, it is difficult for the sound field control device to perform optimal sound field control for every song once it has been set. Optimal sound field control becomes necessary. In addition, in the case of lighting, the lighting changes in response to the input signal level, so in parts of the song where the level is high, the lighting is bright (and where the level is low, the lighting is dimmed, and it is continuous). In addition, in the case of level detection, there is a detection time constant, which does not synchronize with changes in the song and gives a slightly delayed feeling, making it difficult to synchronize music and lighting, or to optimize the relationship between music and sound field. There were problems in terms of gender or effectiveness.

Furthermore, the performance of music signals, as typified by CDs (compact discs), DATs (digital audio tape recorders), etc., has improved markedly. but,
On the other hand, in sound reproduction equipment, especially speakers, there are many problems with reproduction of low frequency ranges and directivity characteristics and attenuation characteristics of high frequency ranges in the sound field.

The present invention has been developed in view of the above-mentioned problems, and the spatial nature of the sound field and lighting change according to the tempo and rhythm of the song, regardless of the level of the input signal, and furthermore, the input signal contains low-frequency components. However, if there is a shortage of low frequency components in the sound field, or if there is a shortage of high frequency components in the sound field, especially at the listening point, even though the input signal contains high frequency components, it is necessary to compensate for the shortage. The present invention provides a complementary sound reproduction device.

Means for Solving the Problems In order to solve the above problems, the present invention provides an audio signal reproducing device, an autocorrelation function calculation circuit that calculates an autocorrelation function based on a signal from the audio signal reproducing device, and a a first autocorrelation coefficient converter that converts an output signal from the function calculation circuit into a control signal that controls a sound field control device; and a sound field control device that controls a signal from the acoustic signal reproduction device using the control signal. a second autocorrelation coefficient converter that converts an output signal from the autocorrelation function calculation circuit into a lighting dimming signal; a dimming equipment lighting device that receives the lighting dimming signal as an input; a first cross-correlation function calculation circuit that calculates a cross-correlation function by passing a signal from the acoustic signal reproduction device and a signal from a sound field sensor provided in the reproduction sound field through a low-pass filter, respectively; and the acoustic signal reproduction circuit. a second cross-correlation function calculation circuit that calculates a cross-correlation function by passing a signal from the device and a signal from a sound field sensor provided in the reproduction sound field through a high-pass filter, respectively; and the first cross-correlation function calculation circuit. a first cross-correlation coefficient conversion circuit that converts an output signal from the circuit into a first control signal; a deep bass adding device that controls the output signal from the low-pass filter using the first control signal; a second cross-correlation coefficient conversion circuit that converts an output signal from the second cross-correlation function calculation circuit into a second control signal;
:A high frequency correction circuit.

Effect: By calculating the autocorrelation function of the acoustic signal and controlling the sound field control device and lighting device according to the value of the autocorrelation coefficient, the sound field control effect can be achieved in synchronization with the tempo and rhythm of the song. It is now possible to obtain lighting effects, calculate the cross-correlation function between the acoustic signal and the sound field sensor, and use the value of the cross-correlation coefficient to control the amount of deep bass added, furthermore to control the treble range. It is possible to obtain sound quality and music space with a good balance between the bass and treble ranges.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows the bottom of a tank of a sound reproducing device according to an embodiment of the present invention. In FIG. 1, 1 is an acoustic signal reproducing device, 21 is an output signal, 2-1°2-n is a bandpass filter 3-1. ... 3n is an autocorrelation function calculation circuit, 4-1. ...14n is an autocorrelation coefficient conversion circuit, 5
-1. ..., 5-n is an autocorrelation coefficient conversion circuit, 6 is a sound field control device, 7 is a dimming equipment lighting device, 8 is a sound field sensor,
9 is a low-pass filter, 10 is a cross-correlation function calculation circuit, il is a cross-correlation coefficient conversion circuit, 12 is a heavy bass adding device, 13 is a high-pass filter, 14 is a cross-correlation function calculation circuit, and 15 is a cross-correlation coefficient conversion circuit. , 16 is a high frequency correction circuit.

The operation will be explained below.

The music signal reproduced from the audio signal reproduction device 1 becomes an output signal 21, which is transmitted through a plurality of bandpass filters 3-1.・・・
・, passes through 3-n. Usually this bandpass filter is 3
The band is divided into ~4 bands.

As for the band, the cutoff frequency fcl in the case of three divisions is set to 100 to 2oo11Z, and fcz is set to around 3 to 5KH2. In addition, the cutoff frequency fcI in the case of 4 divisions is 100H2, f, , is I KH2, f C3
are set around 5KIIZ. The signal passing through the above bands is sent to the autocorrelation function calculation circuit 3-1.・
...3-n is entered, and the autocorrelation function is calculated.

Generally, the autocorrelation function φχχ(τ) of a certain signal χ(1) is given by the following equation. However, T is the synchronization of the signal χ(shi).

A certain delay time τ1. τ2. . . , the correlation coefficients for n τs at τ7 can be measured using the circuit shown in FIG.

The input signal χ(j) 20 is connected to the direct signal 21 and the delay circuit 22-
1, . . . , 22-n, the delayed signals 23-1 .・・・
. , 23n are the multipliers 24-1 . . . , 24-n, and an averaging circuit 25-1 . ..., 2
5-n for a certain delay time τ1. τ2. ...
, τ7 can be found.

When looking at the envelope of the autocorrelation function depending on the characteristics of the music signal, a tendency as shown in Figure 3 can be seen.

In FIG. 3, the autocorrelation function is a function of delay time τ, and the enrove of the autocorrelation function is, for example, the original signal (frequency 5
The autocorrelation function for KllZ) is as shown in FIG. When looking at the magnitude of the correlation coefficient, it can be expected that the value will vary greatly depending on the value of the delay time τ even if they are very close. Therefore, the delay time τ. It is easier to express the characteristics of music signal 3 by determining the enherobe and defining it by its DC output voltage to see the correlation coefficient in (Fig. 4 (C)). The circuit shown in FIG. 2 is used to determine this characteristic. This circuit is used to determine the characteristics of the music signal, and the delay time τ, ~τ. When expressing the relationship between the voltage and the DC output voltage, there are trends a, b, and c in FIG. 3.

As shown in (1) 2, the autocorrelation function is the correlation with itself at a certain delay time, so as a physical characteristic of the music signal, fast-tempo songs and rhythmic songs have a small correlation coefficient, while slow-tempo songs have a small correlation coefficient. Songs have a large correlation coefficient.

The values calculated by the autocorrelation function calculation circuits 3-■, ..., 3-n become the correlation coefficients, and the autocorrelation coefficient conversion circuits 4-1
．． . . , 4-n converts the output signal 21 from the acoustic signal reproduction device 1 into a control signal to control the sound field control device 6. On the other hand, autocorrelation coefficient conversion circuit 5-1. ...,
5-n, it is converted into a signal for controlling the lighting device, and controls the dimmer lighting device 7.

Further, the output signal 21 from the acoustic signal reproducing device 1 and the output signal 30 from the sound field sensor each pass through a low-pass filter 9. This low-pass filter 9 has a cutoff frequency fcl set to approximately 1001 (Z).

The signals that have passed through these two filters enter a cross-correlation function calculation circuit IO, where a cross-correlation function is calculated.

In general, the cross-correlation function φχy of a certain signal χD) and yct>
(τ) is given by the following formula.

A certain delay time τ, ..., τ. In order to obtain the cross-correlation coefficients for n τ's, measurement can be performed using the circuit shown in FIG.

Even though the acoustic signal contains many components of 10011Z or less, if there are few components of 10011Z or less from the sound field sensor, this cross-correlation coefficient will have a small value. On the other hand, when the cross-correlation coefficient is large, sufficient low-frequency components appear in the sound field. Therefore, in the cross-correlation coefficient conversion circuit 11, a control signal 27 for controlling the amount of addition to the output signal 28 from the low-pass filter is input to the deep bass adding device 12 using a function as shown in FIG.

In FIG. 5, the relationship between the DC output voltage 27 of the cross-correlation coefficient and the amount of heavy bass added is to be added in the relationships a, b, (() as shown in the figure depending on the effect and purpose. In other words, the same In diagram a, the amount of addition decreases rapidly as the correlation coefficient increases, in b, it changes in a linear relationship, and in C, contrary to a, the amount of addition gradually changes even when the correlation coefficient changes, up to a certain size. It changes the

Similarly, even though the acoustic signal contains many high-frequency components, if there are few high-frequency components from the sound field sensor, this cross-correlation coefficient will have a small value. On the other hand, when the cross-correlation coefficient is large, sufficient high-frequency components appear in the sound field. Therefore, in the cross-correlation coefficient conversion circuit 15, the output signal 1 from the high-pass filter 13 is
The control signal 18 that controls the amount of correction to the high frequency correction circuit 1
Enter into 6.

In FIG. 5, the concept of the relationship between the DC output voltage 17 of the cross-correlation coefficient and the high frequency component correction amount is the same as the relationship with the deep bass addition amount described above.

Note that as a configuration other than the present embodiment, it is also possible to perform calculations in the same manner for the entire i) range of the music signal without using the bandpass filter as shown in FIG.

Effects of the Invention As described above, the present invention calculates the autocorrelation function of the output signal from the acoustic signal reproducing device, and controls the sound field control device and the lighting device according to the value of the coefficient.

Furthermore, the cross-correlation function between the output signal and the output signal from the sound field sensor is calculated, and the amount of addition of deep bass and the amount of correction of high-frequency components are controlled according to the value. It is possible to enhance the acoustic and lighting effects of

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an audio reproduction device according to an embodiment of the present invention, FIG. 2 is a block diagram showing a configuration example of an autocorrelation function calculation circuit used in the present invention, and FIG. 3 is a block diagram showing an example of the configuration of an autocorrelation function calculation circuit used in the invention. FIG. 4 is a waveform diagram of the original signal and autocorrelation function, FIG. 5 is a block diagram showing a configuration example of a cross-correlation function calculation circuit used in the present invention, and FIG. 6 is a diagram showing the cross-correlation coefficient and Relationship diagram between heavy bass addition amount and high frequency component correction amount, 7th
Figure 8 is a block diagram showing another embodiment of the present invention.
9 are block diagrams of a conventional sound reproduction device. ■...Acoustic signal reproducing device, 2...Band pass filter, 3...Autocorrelation function calculation circuit, 4.5...Autocorrelation coefficient conversion Circuit, 6...
... Sound field control device, 7 ... Light control equipment lighting device, 8 ... Sound field sensor, 9 ... Low pass filter, 10.14 ... ... Cross-correlation function calculation circuit, 11.15 ... Cross-correlation coefficient conversion circuit, 12 ... Deep bass addition device, 13 ...
Bypass filter, 16... High frequency correction circuit.

Claims (3)

[Claims] (1) An audio signal reproduction device, an autocorrelation function calculation circuit that calculates an autocorrelation function based on the signal from the audio signal reproduction device, and an output signal from the autocorrelation function calculation circuit to control a sound field control device. a first autocorrelation coefficient conversion unit that converts the output signal from the autocorrelation function calculation circuit into a control signal; a sound field control device that controls the signal from the audio signal reproduction device using the control signal; a second autocorrelation coefficient converting unit that converts into a light signal; a dimming equipment lighting device that receives the lighting dimming signal as input; and a signal from the acoustic signal reproducing device and a reproducing sound field provided in The signal from the sound field sensor is passed through a low-pass filter,
A first cross-correlation function calculation circuit calculates a cross-correlation function, and a cross-correlation function is calculated by passing the signal from the acoustic signal reproduction device and the signal from a sound field sensor provided in the reproduction sound field through high-pass filters, respectively. a second cross-correlation function calculation circuit for calculating, a first cross-correlation coefficient conversion circuit for converting an output signal from the first cross-correlation function calculation circuit into a first control signal, and the first control a deep bass adding device that controls the output signal from the low-pass filter using a signal; and a second cross-correlation coefficient conversion circuit that converts the output signal from the second cross-correlation function calculation circuit into a second control signal. and a high-frequency correction circuit that controls an output signal from the high-pass filter using the second control signal. (2) The audio according to claim 1, wherein the autocorrelation function calculation circuit calculates the autocorrelation function based on a signal passed through a group of bandpass filters that divides the output signal from the audio signal reproduction device into a plurality of frequency bands. playback device. (3) The first autocorrelation coefficient converter and the second autocorrelation coefficient converter have different conversion characteristics.
1) The sound reproduction device described above.