JPS58206300A - Sound reproducing device - Google Patents

Abstract

PURPOSE:To give a listener various realism of sound, by providing a convolution equalizer to a signal transmission line connecting speakers arranged right and left sides in front of the listener in order to let the listener sense sound from optional direction and distance other than from the actual position of the speakers. CONSTITUTION:An input signal is inputted in a delaying device 12 which consists of plural delay elements 12-1, 12-2-12-(n) connected in series. The output of each of delay elements which constitute the delaying device 12 are totally added by an adder 14 through coefficient multipliers 13-1, 13-2-13-(n) to be outputted to an output terminal 15. Convolution equalizers 2 and 3 composed of a convolution integrating circuit optionally set the coefficient of each coefficient multipliers so that the impulse response to the equalizers can be set to have an optional waveform. For concretely setting the coefficient of the equalizers 2 and 3, a data related to the position of a virtual speaker 8, etc., is preliminary stored so that data of various directions can be set to each coefficient multiplier.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sound reproduction device configured to apply an acoustic signal to speakers placed in front of a listener on the left and right sides, and in particular, the present invention relates to an audio reproduction device configured to apply an acoustic signal to speakers placed in front of a listener on the left and right sides, and in particular to a sound reproduction device configured to apply an acoustic signal to speakers placed in front of a listener on the left and right sides. It is an object of the present invention to provide a sound reproduction device that allows the user to perceive sound and provides various sound field sensations.

Generally, when a sound/sound signal is commonly input to speakers placed in front of the recipient on the left and right, and the sound image reproduced from the left and right speakers is perceived at any position other than the left and right speaker positions. , fl″i to the left and right speakers above.
Gino had installed a control system that included an equalizer in the transmission line. However, as a means of realizing the above-mentioned equalizer, a control method that changes the Bode-shaped amplitude frequency characteristic and a method that combines phase thick or single delay have traditionally been used, so virtual speakers are placed in both ears of the listener. The problem was that it was difficult to accurately reproduce the waveform when the sound was produced, making it difficult to obtain a satisfactory effect.

The present invention solves these conventional drawbacks,
A convolution equalizer (hereinafter referred to as a convolver) consisting of a convolution and integration circuit is installed in the signal transmission path to the left and right speakers to reproduce faithful sound images and sound quality by accurately reproducing the target waveform in both ears of the listener. It is configured so that it can be done.

The present invention will be described below with reference to drawings of embodiments. FIG. 1 shows an embodiment of the present invention. In FIG. 1, 1 is an input terminal for input signals, 2 and 3 are convolvers, 4 and 6 are left and right speakers, 8 is a virtual speaker, and 9 is a convolver. Be the listener. "2 Convolver 2. 3 passes the human input signal applied to the input terminal 11 through a delay device 12 which has a plurality of delay elements 12-1, 12-2, . . . 12-n connected in cascade, as shown in FIG. Delay elements 12-1, 12-2, .
The outputs from 2-n are respectively input to coefficient multipliers 13-1. 13
-2 . . . 13-n, the adder 14 adds the total sum and outputs the result to the output terminal -r16.

The convolvers 2 and 3 each have a coefficient unit 13-1. ．． 13-2
By setting the coefficient of 13-n to 1, it is possible to set this component impulse response to an arbitrary waveform.

Therefore, how to obtain the coefficients of each coefficient unit will be described above.

In FIG. 1, the convolvers 2 and 3 have m stages, and each tap coefficient is ''.

In addition, the measurement value obtained by sampling each transmitted impulse response from the speakers 4 and 5 to both ears 6 and 7 of the listener 9 with the delay time between the convolver's 1st column is taken as the measurement value from the speakers 8 to both ears 6 and 7 of the listener 9. Please do the same with your response.

Now, in FIG. 1, when an impulse is input to the input terminal 1, a signal is generated in both ears 6 and 7 of the listener 9 as a result of convolving the convolver coefficient and each transmitted impulse response.

In other words, if the impulse response of both ears is +1111, the equation (5) can be expressed as, and furthermore, y=HX...ke)
It can be expressed as Also, m-1 from 1hφ1 and 1hφ6 respectively.
Define the following f by adding 1 to 0.

Here, an evaluation function P is defined as the degree of approximation of y to f.

, = (v-f)T (, P-f)
= (x”HT-f”) (Hx-f)=x”H
"Hl-(zTH"f ten f"Hx)+f"f・
...(9) Here, in order to find the X that minimizes P, partial division by X yields 1 H"Hx= H"f Therefore, x= (HT H)-' HT f
---...(1o) is obtained.

Therefore, by setting each coefficient of JCr+Jt, which is an element of I, in the coefficient multipliers of the convolvers 2 and 3, the impulse responses of the speaker 8 in both ears 6 and 7 of the listener 9 can be synthesized.

FIG. 3 shows another embodiment of the present invention. In FIG. 3, 1 is an input terminal for an input signal, 22 is a convolver with m stages, 23 is a convolver with 4 stages, and 4 and 5 are convolvers with four stages. They are left and right speakers. As shown in FIG. 4, the convolver 22 transfers the input signal from the input terminal 1 to m delay elements 3.
1-1.31-2...31-m are passed through the delay devices 31 connected in cascade, and each delay device -1'31-1.31-2
. . . The outputs from 31 to m are respectively sent to the coefficient unit 32.
-1, 32-2, . The convolver 23 converts the output of the convolver 22 into delay elements 34-1, 34-2, .
...34-k is passed through the cascade-connected slow & L device 34,
The output from each delay element 34-1.34-2...34-k is set to a coefficient of 8 35-1.36-2...
. . 36-k, the adder 36 performs the summation and adds the result to the right speaker 4.

In FIG. 3, convolver 22 is the same as convolver 2 in FIG. 1, but convolver 23 differs from convolver 23 in FIG. 1 in the number of stages and coefficient values. Here, assuming that the number of stages of the convolver 23 in FIG. 3 is k (kpm) and its value is 10, the coefficient is determined.

Since the coefficient of the convolver 23 is If, it can be expressed by a convolution calculation of the responses UJr and JL of the convolver 23 when an impulse is input to the input terminal 1. If this rA calculation is expressed in 11 columns and the impulse response output of the convolver 23 is (d+, dz... dm+ -+), then D = , ZD, LB, and the - direction is 1t. The degree of approximation of UKJI of D by creating a row U by adding 1 and 1 0s is defined as the evaluation relationship q as follows.

-+ to m+: (D-U)T(D-U) = Cx6xO-11)" (xDxo-U) To find Io that minimizes q, differentiate by 1° and θx.

Then, xD" JD xc=x, U is obtained, and x(, = (xD", 10) -' JD U is obtained.

An effect equivalent to that shown in FIG. 1 in which Io is set in the convolver 23 can be achieved with a smaller number of taps.

Basically, to set the coefficient of convolver 22+23, use f
l! Concerning a coefficient unit consisting of a calculation type D mumulverter,
A microcomputer 19 for setting the number of speakers, a memory circuit 20 for pre-memorizing speaker data of devices such as the virtual speaker 8, etc. It is possible to set it to the IE and the I/O units, and a common convolver can have 4 different functions. By converting the convolver connections into a common part and a difference part in this way, the number of convolver stages in the difference part can be reduced, and cost reduction due to simplification becomes possible.

As described in detail above, according to the present invention, a convolution equalizer constituted by a convolution and integration circuit is installed in the transmission path to the left and right speakers, so that the target waveform is accurately transmitted to both ears of the listener. It has the advantage that it can be reproduced and the listener can reliably perceive the sound image according to the waveform.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing one embodiment of the acoustic first f production device of the present invention, Fig. 2 is a block diagram of the main parts of the same device, and Fig. 3 is a block diagram showing another embodiment of the same device. 4 are specific circuit diagrams thereof. 2.3...compol/<, 22+ 23...
...Convolver, 4,6...Speaker. Name of agent: 'i11 Physician Toshio Nakao and 1 other person
Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] A sound reproduction device that includes a convolution equalizer configured with a convolution integrating circuit in a signal transmission path to speakers placed on the front left and right sides of a receiver.