JPH03145300A - Audio reproducing device - Google Patents

Abstract

PURPOSE:To obtain more natural sound field effect independently of the difference from kinds and arranging way of speakers of each channel by correcting the frequency characteristic of an audio signal of each channel so as to make the sound tone of the speaker of each channel equal to each other. CONSTITUTION:The frequency characteristic of speakers of each channel is measured by using a measuring microphone 24 placed near a viewer 14 and the information is sent to a control circuit 21 as a measuring signal 25. The control circuit 21 based on the measuring signal 25 from the measuring microphone 24 controls the frequency characteristic correction pattern of frequency characteristic control circuits 15-18 of each channel with a control signal A22 so that the frequency characteristics of the speakers of each channel are made equal to each other. Since the main speaker is a right channel speaker 7 or a left channel speaker 11, the control circuit 21 applies frequency correction based on the frequency characteristic of the right channel speaker 7 or the frequency characteristic of the left channel speaker 11. Thus, natural sound field effect is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to correction of sound field effects in an audio reproduction device having a plurality of audio channels.

[Conventional technology]

FIG. 2 is a block diagram of an audio reproducing device that reproduces 4-channel audio of, for example, 3-1 system 4-channel stereo for high-definition; in the figure, l is a 4-channel audio source, such as /) Ivision TV receiver. It is. 2 is the right channel audio signal sent from the 4-channel audio source 1, and 3 is the 4-channel audio source 1.
It is a center channel audio signal sent from 4
is the left channel audio signal sent out from the 4-channel audio source 1, and 5 is the rear channel audio signal sent out from the 4-channel audio source 1. Further, 6 is an amplifier circuit for power amplifying the right channel audio signal 2, 7 is a right channel speaker driven by this amplifier circuit 6, 8 is an amplifier circuit for power amplifying the center channel audio signal 3, and 9 is the center channel full speaker power driven by this amplifier circuit 8; 10 is an amplifier circuit for power amplifying the left channel audio signal 4;
11 is a left channel speaker driven by this amplifier circuit 10, 12 is an amplifier circuit for power amplifying the rear channel audio signal, 13 is a rear channel speaker driven by this amplifier circuit 12, and 14 is a left channel speaker driven by this amplifier circuit 10. It is. 15 is a TV that reproduces, for example, a high-definition video signal.

Next, the operation will be explained.

The four-channel audio signals 2, 3, 4, and 5 emitted from the 4-channel audio source 1 are independently power-amplified by four amplifier circuits 6, 8, 10, and 12, and the power is amplified by the right channel speaker 7 and the center channel. Speaker 9. Left channel speaker 11. It is converted into audio by the rear channel speaker 13 and perceived by the viewer 14.

[Problem to be solved by the invention]

A conventional audio playback device is configured as described above. Due to issues such as cost, the rear channel speakers 13 are often of a different type from the front channel speakers. If the type of speaker is different, the tone of the speaker will be different. For example, when the sound moves from the front channel speaker to the rear channel speaker 13, the sound will move unnaturally due to the difference in the tone of the front channel speaker and the rear channel speaker 13. becomes. Furthermore, due to problems such as installation space, the center channel speaker 9 is often placed below the TV 15 as shown in FIG. In such an installation, even if the types of speakers 7, 9, and 11 for each front channel are the same, the tones of the speakers will differ depending on how they are placed. For example, the sound will change from right channel speaker 7 to center channel speaker 9. →When moving with the left channel speaker 11, the sound will move unnaturally due to the difference in tone of the front channel speakers 7, 9, and 11. In conventional audio playback devices, as described above, the difference in tone between the speakers of each channel results in an unnatural sound field effect.

The present invention was made to solve the above-mentioned problems, and an object of the present invention is to provide an audio reproduction device that can obtain a more natural sound field effect.

[Means to solve the problem]

The audio reproduction device according to the present invention includes a frequency characteristic correction circuit that corrects the frequency characteristics of the audio signal of each channel in order to make the tone of the speakers of each channel the same, and a frequency characteristic correction circuit that measures the frequency characteristics of the speaker of each channel. A signal generation circuit that generates a signal, a measurement microphone that measures the frequency characteristics of the speaker of each channel, a frequency characteristic correction pattern of the frequency characteristic correction circuit, and a channel that the signal generation circuit sends a signal to. A control circuit is also provided.

[Effect]

The audio reproduction device according to the present invention sequentially sends a signal generated by a signal generation circuit to each channel, and measures the frequency characteristics of the speakers of each channel using a measurement microphone, while ensuring that the frequency characteristics of the speakers of each channel are the same. Correct the frequency characteristics of the audio signal of each channel so that the timbre of the speaker of each channel becomes the same.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 15 is a frequency characteristic correction circuit for correcting the frequency characteristics of the right channel audio signal 2, 16 is a frequency characteristic correction circuit for correcting the frequency characteristics of the center channel audio signal 3, and 17 is the frequency of the left channel audio signal 4. 18 is a frequency characteristic correction circuit that corrects the frequency characteristic of the rear channel audio signal 5; 19 is a signal generation circuit that generates a signal for measuring the frequency characteristic of the speaker of each channel; 20 21 is a signal generated by this signal generation circuit 19, and 21 is a frequency characteristic correction pattern of the frequency characteristic correction circuits 15, 16, 17, and 18 of each channel, and control for controlling which channel the signal generation circuit 19 sends a signal to. A circuit 22 is a control circuit 21 which is connected to the frequency characteristic correction circuits 15, 16, 1.
7. Control signal A for controlling 18, 23 is a control signal B for controlling this control signal 21 and the signal generation circuit 19, 24 is a measurement microphone for measuring the frequency characteristics of the speaker of each channel. , 25 are measurement signals sent from this measurement microphone 24. The other parts are the same as those of the conventional example, so the explanation will be omitted.

Next, the operation will be explained.

The signal generation circuit 19 generates a signal for measuring the frequency characteristics of the speaker of each channel, and the generated signal 20
is sent to each channel in sequence at predetermined time intervals by the control signal B23 from the control circuit 21, for example, right channel → center channel → left channel → rear channel → right channel → center channel → left channel → rear channel →... Sent like this. At this time, the measurement microphone 24 placed near the viewer 14
The frequency characteristics of the speakers of each channel are measured, and this information is sent to the control circuit 21 as a measurement signal 25. The control circuit 21 receives a measurement signal 25 from the measurement microphone 24.
The frequency characteristic correction circuit 15 of each channel is configured to make the frequency characteristics of the speakers of each channel the same based on
, 16.17°18 are controlled by the control signal A22. The main speaker is right channel speaker 7 or left channel speaker 11, so
The control circuit 21 corrects the frequency characteristics based on the frequency characteristics of the right channel speaker 7 or the frequency characteristics of the left channel speaker 11.

Here, as an example of frequency characteristic correction, a case where frequency characteristic correction is performed based on the frequency characteristic of the right channel speaker 7 will be described using FIG. 4.

FIG. 4 is a diagram showing before and after correction of the frequency characteristics of the other channel audio signals with the stone channel audio signal as a reference.

For example, suppose that the results of measuring the frequency characteristics of the speakers of each channel using the measurement microphone 24 are as shown in the left side of FIG. 4 before the frequency characteristics are corrected.

Therefore, the control circuit 21 uses the control signal A22 based on the measurement signal 25 from the measurement microphone 24 as shown in FIG.
The frequency characteristics of the low range of the left channel audio signal 4 as shown in b) and the high range of the center channel audio signal 3 and rear channel audio signal 5 as shown in Figures (C) and (d) are gradually corrected. . The generated signal 20 is circulated to each channel several times, and the frequency characteristics of the speaker of each channel become to some extent different from the reference right channel audio signal, as shown after correction on the right side of FIG. Tara,
The control circuit 21 uses a control signal B23 to stop the signal generation circuit 19 from generating a signal, and the control circuit A22 causes the frequency characteristic correction circuits 15 and 16.17° I8 of each channel to hold the frequency characteristic correction pattern at this time. If the channel audio source 1 is played back in this state, the viewer 14 will hear that the tones of the speakers 7.9 and 11.13 of each channel are the same.

Note that since the measurement microphone 24 measures the frequency characteristics of a plurality of speakers, the measurement microphone 24 is assumed to be omnidirectional or equivalent to omnidirectional.

In the above embodiment, the case of 4-channel audio has been described, but it can be applied to multi-channel audio of 2 or more channels, and the same effects as in the above embodiment can be achieved. Further, in the above embodiment, a case of 3-1 system 4-channel stereo for high-definition has been described, but Dolby Pro Logic system may also be used, and the same effects as in the above embodiment can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, in an audio reproduction device having a plurality of audio channels, the frequency characteristics of the audio signal of each channel are corrected so that the tone of the speaker of each channel is the same. This has the effect of providing a more natural sound field effect, regardless of the type or placement of speakers for each channel.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an audio reproducing device according to an embodiment of the present invention, FIG. 2 is a block diagram showing a conventional audio reproducing device, FIG. 3 is a diagram showing a general speaker arrangement, and FIG. 4 is a block diagram showing a conventional audio reproducing device. FIG. 3 is a diagram showing an example of frequency characteristic correction. 15.16, 17.18 are frequency characteristic correction circuits for each channel, 19 is a signal generation circuit, 20 is a generated signal, 21 is a control circuit, 22 is a control signal A, 23 is a control signal B, 24
is a measurement microphone, and 25 is a measurement signal. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) In an audio reproduction device having multiple audio channels, a frequency characteristic correction circuit that corrects the frequency characteristics of the audio signal of each channel so that the tone of the speaker of each channel is the same, and the frequency characteristic of the speaker of each channel. a measurement microphone for measuring the frequency characteristics of the speaker of each channel, a frequency characteristic correction pattern of the frequency characteristic correction circuit, and a channel to which the signal generation circuit is connected. An audio playback device comprising: a control circuit for controlling whether to send a signal.