JPH06125600A - Three speaker system - Google Patents

Abstract

PURPOSE:To eliminate the missing of sound image and to provide a good stereophonic sense by calculating the correlation value of each band-divided speaker signal and generating a driving signal for speaker. CONSTITUTION:A left channel signal EL and a right channel signal ER are band-divided by n-number of BPF-Li (L1-Ln) and Ri (R1-Rn). The divided left and right channel signals are supplied to the outputs for right and left and central speaker driving signals by n-number of signal generators ri (r1-rn). By adding each output by adders A1-A3, signals EL, ER, and EC for driving right and left and central speaker are prepared. In the preparing device ri, a correlation value R1, i is calculated by a correlation value calculating device ri based on the right and lift channel signals which are band-divided by BPF-Li and Ri. A signal distributing device S generates the signals EL, ER, and EC based on the correlation value R1, i and the right and left channel signals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-speaker system used in a stereo signal reproducing type audio apparatus.

[0002]

2. Description of the Related Art As a conventional technique according to the present invention, there is, for example, Japanese Patent Laid-Open No. 3-9700. This publication shows that the drive signals for the left, right, and center speakers are set as in the following equation 1.

[0003]

[Equation 1]

As described above, conventionally, by supplying a drive signal to each speaker, even when the distance between the left and right speakers is relatively large from the listener's perspective, the phenomenon of hollowing out of the sound image is suppressed, and the left and right speakers are suppressed. An attempt has been made to provide a three-speaker system capable of improving separation of original signals and obtaining a sufficient stereo feeling.

[0005]

However, a stereo signal usually contains signals from a plurality of sound sources having different frequency components and different positions (directions), and these need to be processed separately. The conventional method described above has a drawback that all signals are processed in the same manner.

Further, as is clear from the above formula 1, when the signals of E _R and E _L are made to have opposite phases in order to give a feeling of expansion of the sound field, the denominator becomes very small and the generated signal diverges. There was a problem.

Further, there is a problem that sound is emitted from the central speaker even when the E _R and E _L signals are almost uncorrelated.

Therefore, the present invention includes signals from a plurality of sound sources.
In case of rare signals, E_R And E_L 
Is the opposite phase, left and right as seen by the listener even when they are unrelated
Even if the speaker spacing of the
Eliminates the phenomenon _R And E_L The separation of
3-speaker system that can obtain a sufficient stereo feeling
It is intended to provide a system.

[0009]

According to the present invention, an original signal for a left speaker and an original signal for a right speaker, a left speaker and a right speaker which are respectively arranged on the left and right and are driven by the respective signals, and between these two speakers. A central speaker arranged, a band pass filter that divides the left speaker signal and the right speaker signal into a plurality of bands, a correlation value calculation unit that calculates a correlation value of each band-divided speaker signal, The signal distribution means generates a left speaker drive signal, a right speaker drive signal, and a center speaker drive signal according to the calculated values of the correlation value calculation section.

[0010]

According to the above construction, in the case of a signal containing signals from a plurality of sound sources, or in the case of signals separately from each other, E _R and E _L
When the phase is opposite, or when the distance between the left and right speakers is relatively large when viewed from the listener, it is possible to suppress the phenomenon of hollowing out of the sound image.
Moreover, the separation between E _R and E _L can be improved to obtain a sufficient stereo feeling.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the three-speaker system of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram of a three-speaker system, in which the left channel signal (original signal) E _L and the right channel signal (original signal) E _R are respectively n band pass filters L.
band division by i (L1 to Ln) and Ri (R1 to Rn),
The band-divided left and right channel signals are converted into left and right and center speaker drive signal outputs by n signal generators γi (γ1 to γn), and the outputs are added by adders A1 to A3 to add left and right and center signals. Speaker drive signals E _L ', E _R ',
It is configured to create E _C '.

The signal generator γi comprises a correlation value calculator ri and a signal distributor S as shown in FIG. 2, and operates as follows. That is, the band pass filters Li, Ri
In the correlation value calculator ri, the correlation value R _{t, i} is calculated from the left and right channel signals band-divided in step 1 according to the following _equation 2.

[0014]

[Equation 2]

Further, from the calculated correlation value R _{t, i} and the left and right channel signals, the signal distributor S generates left and right and center speaker driving signals E _L ′, E _R ′, E _C ′. The following equation is an example of a rule for generating such a signal.

[0016]

[Equation 3]

[0017]

[Equation 4]

However, in the case of the above equations 3 and 4, the correlation value R
_In this example, the signal calculation formula is conditionally branched depending on the signs of _{t and i} .

[0019]

As described above, according to the present invention, in the case of a speaker signal containing signals from a plurality of sound sources, E _R and E _L are anti-phase and uncorrelated with each other. In this case, when the distance between the left and right speakers is relatively large when viewed from the listener, the phenomenon of hollowing out of the sound image is suppressed, and E _R and E
_The effect of providing a three-speaker system that can obtain a sufficient stereo feeling by improving the separation from _L can be expected.

[Brief description of drawings]

FIG. 1 is a block diagram of a three speaker system of the present invention.

FIG. 2 is a detailed diagram illustrating the signal generator of FIG.

[Explanation of symbols]

E _L Left speaker original signal E _R Right speaker original signal E _L 'Left speaker drive signal E _R ' Right speaker drive signal E _C 'Center speaker drive signal L1 to Ln Left channel band pass filter R1 to Rn Right channel Band pass filter ri Correlation value calculator S Signal distributor

Claims (1)

[Claims] 1. An original signal for a left speaker and an original signal for a right speaker, a left speaker and a right speaker which are respectively arranged on the left and right and driven by each of the signals, and a central speaker arranged between these speakers, A band pass filter that divides the left speaker signal and the right speaker signal into a plurality of bands, a correlation value calculation unit that calculates the correlation value of each band-divided speaker signal, and a calculation value of the correlation value calculation unit A three-speaker system comprising: a left speaker drive signal, a right speaker drive signal, and a signal distribution means for generating a central speaker drive signal.