WO2006106690A1

WO2006106690A1 - Acoustic signal processing device

Info

Publication number: WO2006106690A1
Application number: PCT/JP2006/306337
Authority: WO
Inventors: Moriyuki Oshima; Mitsuo Nakazato; Shigeki Kobayashi; Akira Shimizu; Osamu Yoshizawa; Koji Takano; Kunio Toyoda; Shinjiro Kato
Original assignee: Pioneer Corporation
Priority date: 2005-03-31
Filing date: 2006-03-28
Publication date: 2006-10-12

Abstract

An acoustic signal processing device includes: a signal processing unit (20) for outputting signals of two systems, i.e., A system and B system; and A system and B system signal paths (30, 40) for generating a normal phase signal and a reverse phase signal and outputting them to normal phase terminals (61, 67) and reverse phase terminals (63, 65), respectively. The acoustic signal processing device can be used for unbalanced output by selecting a predetermined terminal or for balanced output. The acoustic signal processing device further includes: judging means (50, 80) for judging whether the A system and the B system have the same output destination band; and switching means (25) arranged between the A system signal path (30) and the B system signal path (40) for outputting the signals of the two systems to their normal phase terminal and the reverse phase terminal, respectively, if the bands of the two systems are different according to the judgment of the judging means and branching one of the A system signal and the B system signal into two and outputting to the other normal phase terminal and the reverse phase terminal if the two systems have the same band.

Description

Specification

Acoustic signal processing device

Technical field

TECHNICAL FIELD [0001] The present invention relates to an acoustic signal processing device that inputs, for example, a digital signal and performs predetermined signal processing and then outputs the acoustic signal processing device. The present invention relates to a signal processing device.

Background art

[0002] In recent years, with the development of digital technology, various types of sound reproduction apparatuses that digitally process sound signals and reproduce various sound fields like movie theaters and concert halls have been provided. With this sound playback device, users can enjoy commercially available DVD movie software and CD music software with a sense of presence in a movie theater or concert hall.

[0003] A conventional general sound reproduction device has a digital 'signal' processor (hereinafter referred to as DSP), a digital-analog 'converter (hereinafter referred to as DAC), and the like. When the microcomputer and! /, U) are controlled, it is configured as one.

[0004] Acoustic signals input from source devices such as DVDs and CDs are subjected to digital signal processing that adds an acoustic effect such as a sense of presence by a DSP. The sound signal processed by the DSP is converted to an analog signal via the DAC. Thereafter, the analog signal is amplified by an amplifier and then output as sound from a speaker (see, for example, Patent Document 1).

[0005] In addition, conventionally, independent signal processing is performed by a DSP and output as at least two signals of the A system and the B system, and the positive phase signal and the anti-phase signal of each system are output. Generate and select the positive and negative phase signals! /, The displacement force and the ground signal to obtain an unbalanced output, or select and balance signals of different phases in the A and B systems An acoustic signal processing device has been proposed that can be used in two ways.

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2005-33727 (Page 2, Figure 6)

Disclosure of the invention

Problems to be solved by the invention [0007] However, in the acoustic signal processing device that can be used in the two ways described above, balance and unbalance, there is a phase shift between the positive terminal output and the negative terminal output during noise output. It has an unsolved problem of doing. In particular, when a sampling 'rate' converter (hereinafter referred to as SRC), which is a frequency change, is provided in the output path from the DSP, the SRC delay time will affect the phase shift. It was a problem.

[0008] The present invention has been made to solve the above-described problems, and in an acoustic signal processing apparatus that can be used in two ways, balanced and unbalanced, a positive terminal output and a negative terminal output during balanced output It is an object of the present invention to obtain an acoustic signal processing apparatus that can reduce the phase shift that occurs between the two.

Means for solving the problem

[0009] In order to solve the above-described problem, an acoustic signal processing device according to the present invention performs predetermined signal processing on an input acoustic signal and then outputs at least two systems of signals A and B A signal processing unit inputs the A system and B system signals, generates a positive phase signal and a negative phase signal, and outputs them to the positive phase terminal and the negative phase terminal, respectively. A signal path, the power to select either the positive phase terminal or the negative phase terminal and the first terminal to make an unbalanced output, and select the terminals of different phases of the A system and the B system In the acoustic signal processing apparatus that can be used as a balanced output or in two ways, the judging means for judging whether or not the output destination bands of the A system and the B system are the same, and In the middle of the A and B system signal paths When the two systems have different bands based on the judgment of the judgment means, the signals of both systems are output to the respective positive phase terminal and the opposite phase terminal, respectively, and when both bands have the same band, A switching means for branching a signal of one of the A system and the B system into two and outputting the signal to the other positive phase terminal and the opposite phase terminal is provided.

Brief Description of Drawings

FIG. 1 is a block diagram of an acoustic signal processing device according to a first embodiment.

FIG. 2 is a front view of the band selector of the acoustic signal processing device according to the first embodiment. FIG. 3 is a front view of a band selector of the acoustic signal processing device according to the second embodiment.

FIG. 4 is a block diagram of an acoustic signal processing device according to a third embodiment.

FIG. 5 is a block diagram of an acoustic signal processing device according to a fourth embodiment.

Explanation of symbols

10 DIR: Digital Audio · Interface · Receiver

20 DSP: Digital · Signal · Processor (Signal processor)

21, 22 Sampling 'rate' converter (frequency converter)

25 changeover switch (switching means)

30 A channel path (A system signal path)

31, 32 DF: Digital 'Filter

40 B channel path (B system signal path)

41, 42, 43, 44 DAC: Digital-to-analog converter

50 Microcomputer (Judgment means)

61, 67 Positive phase terminal

62, 64, 66, 68 Ground terminal

63, 65 Reverse phase terminal

80, 81 Band selector (Judgment means)

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of an acoustic signal processing device according to the present invention will be described in detail. Note that the present invention is not limited to the embodiments. In the following, the outline and features of the acoustic signal processing apparatus of the present invention will be described as embodiments, and then examples relating to the acoustic signal processing apparatus will be described.

[Embodiment]

[0013] The acoustic signal processing device according to the present embodiment inputs an acoustic signal from an input terminal, performs predetermined signal processing on the acoustic signal, and then applies A to the A system output terminal and the B system output terminal. It has a signal processing unit that outputs two signals of system B and system B, respectively.

[0014] The acoustic signal processing apparatus includes a system A signal path connected to the system A output terminal and a system B output. And a B-system signal path connected to the terminal. The A system signal path inputs the A system signal from the A system output terminal, performs predetermined signal processing on this signal, generates a positive phase signal and an antiphase signal of this signal, Outputs to the positive and negative phase terminals, respectively. Similarly, the B system signal path inputs the B system output terminal force B system signal, performs predetermined signal processing on this signal, and then generates a positive phase signal and an opposite phase signal of this signal. And output to the positive phase terminal and the reverse phase terminal, respectively.

[0015] The acoustic signal processing apparatus further includes a determination unit that determines whether or not the output destination bands of the A system and the B system are the same. Furthermore, the acoustic signal processing apparatus has a switching means in the middle of the B system signal path. This switching means outputs the positive and negative phase signals of the A and B systems to the positive and negative phase terminals of the A and B systems, respectively, when the bands of the A and B systems are different. On the other hand, when the band of system A and system B is the same, the switching means branches the system A signal into two, and the system A signal path has the normal phase terminal and the reverse phase terminal as well as the system B signal path. The A system signal is also output to the positive and negative phase terminals.

In the acoustic signal processing device having such a configuration, when the balanced output is obtained by making the output destination bands of both systems the same, the positive phase terminal of the A system signal path and the B system signal path If a noise output is obtained by the signal between the anti-phase terminals and the signal between the anti-phase terminal of the A system signal path and the positive phase terminal of the B system signal path, the phase shift generated between the two signals can be reduced. It can be made extremely small.

[0017] If the A system signal path and the B system signal path each have a frequency converter in the middle of the path, the frequency converter generates a large delay time. If the switching means is provided at the subsequent stage, the phase shift can be effectively reduced. In addition, when the path has a plurality of devices, some delay time is generated in these devices, if not as much as the frequency converter. Therefore, it is better to provide the switching means at a later stage than these devices. More effective. In other words, it is more effective to provide the switching means on the side closer to the output end of the path.

[0018] It should be noted that the switching means of the present embodiment splits the signal of system A into two and splits the signal of system B and B into two. A system and B system It may be a branching branch.

[0019] In addition, the acoustic signal processing device of the present embodiment has an A-system signal path and a B-system signal path. A similar operation may be performed between the two paths. In addition, “A”, “B”, “C”, and “D” in A, B, C, and D systems used in this specification indicate that there are multiple equivalents. Other meanings may be used, for example, “first”, “second”, “third”, “fourth”, etc.

Example

[0020] [Example 1]

FIG. 1 is a block diagram of the acoustic signal processing apparatus according to the first embodiment. Figure 2 is a front view of the band selector. The acoustic signal processing apparatus according to the present embodiment is, for example, an audio master amplifier digital signal processing unit. The acoustic signal processing device includes a digital audio “interface” receiver (hereinafter referred to as DIR) 10, a DSP 20 that is a signal processing unit, an A channel path 30 that is an A system signal path, and a B that is a B system signal path. It has a channel path 40, a microcomputer 50, and a band selector 80.

[0021] The A channel path 30 includes a frequency converter SRC21, a digital 'filter (hereinafter referred to as DF!), And two DACs 41 and 42! /. Similarly, the B channel path 40 has SRC 22, DF 32, and two DACs 43, 44! Between the A channel path 30 and the B channel path 40, a switching switch 25 as switching means is provided. A control signal from the microcomputer 50 is input to the switching switch 25. The band selector signal of band selector 80 is input to DSP 20 and microcomputer 50!

Since this embodiment is a digital signal processing unit of a master amplifier, the output destination band of the A channel is always fixed to the high range. Then, the output destination band of the B channel is switched by the band selector 80 shown in FIG. In other words, if the band selector 80 shown in FIG. 2 selects “HH”, both the A and B channels are in the high range, and if “HM” is selected, the A channel is in the high range, the B channel is in the mid range, If “HL” is selected, the A channel is selected for the high range and the B channel is selected for the low range. [0023] DIRIO inputs a digital signal that is also a digital audio data stream with an external sound source power (not shown), and outputs it to the input terminal 13 of the DSP 20. The DSP20 also inputs a digital signal with 13 input terminals. Then, the DSP 20 performs two independent signals on the digital signal based on the band selection signal from the band selector 80, respectively, as an A channel signal and a B channel signal. Output to output terminal 17 and B channel output terminal 18. The signal processing performed by the DSP20 is right (R) Z left (L) localization, equalizing, networking, etc. All sound processing is performed by the DSP20. The DSP 20 performs this signal processing independently for the A channel and B channel according to the output destination band.

[0024] The signals output to the A channel output terminal 17 and the B channel output terminal 18 enter the A channel path 30 and the B channel path 40, respectively, and are input to the SRCs 21 and 22. The SRCs 21 and 22 that are frequency change ^ ^ perform frequency conversion. Specifically, the 44.1 kHz frequency of the CD standard is upsampled to 96 kHz of the DAT standard. SRC21 improves sound quality and improves sound quality by upsampling.

[0025] The DFs 31 and 32 perform digital filtering on the upsampled signal. In the A channel path 30, the signal digitally filtered by the DF 31 is branched into two and input to the DAC 41 and the DAC 42. The DAC 41 performs digital-to-analog conversion for this signal processing, and then outputs it to the positive phase terminal 61 as the left (L) signal of the A channel. The DAC 42 also performs digital-analog conversion, inverts the signal to the opposite phase, and outputs it to the opposite phase terminal 63 as the right (R) signal of the A channel.

On the other hand, in the B channel path 40, the signal digitally filtered by the DF 32 is branched into two and input to the DAC 43 and the DAC 44. The DAC 43 performs digital 'analog conversion, inverts the signal to the opposite phase, and outputs it to the opposite phase terminal 65 as the B channel left (L) signal. The DAC 44 performs digital-to-analog conversion and outputs it to the positive phase terminal 67 as the right (R) signal of the B channel.

[0027] The switching switch 25 is provided in the subsequent stage of SRC21 and SRC22, and operates according to a control signal from the microcomputer 50. When the terminal S1 and the terminal SO are closed, the SR 25 Input the output of C21 to DF32. That is, the A channel path 30 signal is input to the B channel path 40. On the other hand, when the terminal S2 and the terminal SO are closed, the output of SRC22 is input to DF32 without changing the path. Here, the band selector 80 and the microcomputer 50 determine whether the output destination bands of the A channel and the B channel are the same, and determine whether to switch the switch 25 based on the result. Constitutes the means.

[0028] The acoustic signal processing device configured as described above can be used in two ways, either as a force tolerance output as an unbalanced output or as follows. That is, the left side of the A channel with the positive phase terminal 61 and the ground terminal 62 (L), the right side of the A channel with the reverse phase terminal 63 and the ground terminal 64 (R), and the B channel with the reverse phase terminal 65 and the ground terminal 66 By selecting the right (R) of the B channel using the left terminal (L), positive phase terminal 67 and ground terminal 68, it can be used as a 4-channel unbalanced output. Also, by selecting left (L) with the positive phase terminal 61 and the negative phase terminal 65 and right (R) with the negative phase terminal 63 and the positive phase terminal 67, it can be used as a balanced output of two channels. .

Next, the operation will be described. In this embodiment, as shown in FIG. 2, since the output destinations of both the A and B channels are in the high range, the microcomputer 50 switches the switching switch 25 between the terminal S1 and the terminal SO. Switch to As a result, the A channel signal is split into two, and the A channel signal is output to the B channel as well as the A channel. As a result, the phase shift becomes extremely small.

[0030] In the present embodiment, since the switching switch 25 serving as switching means is provided after the SRCs 21 and 22 that generate a large delay time, the phase shift can be reduced more effectively. I'll do it.

[0031] [Example 2]

FIG. 3 is a front view of the band selector for explaining the acoustic signal processing device according to the second embodiment. When the acoustic signal processing device is used, for example, as a digital signal processing unit of an audio slave amplifier, the band selector that selects which channel is output to which band has two rotary selectors as shown in FIG. It is composed of switches. Other circuit configurations are the same as those in the first embodiment. [0032] If the band selector 81 shown in FIG. 3 is selected, the A channel band is selected for the mid range, and the B channel band is selected for the low range. Since the output destinations of the A and B channels are in different ranges, the microcomputer 50 switches the switching switch 25 so that the terminal S2 and the terminal SO are closed. On the other hand, the band selector 81 of the band selector 81 is input to the DSP 20, and the DSP 20 outputs two signals, each of which is independently processed based on this band selection signal, to the A channel and the B channel. To do. As a result, it can be used as a 4-channel unbalanced output with independent signal processing.

[0033] [Example 3]

FIG. 4 is a block diagram of the acoustic signal processing apparatus according to the third embodiment. In the acoustic signal processing apparatus of the present embodiment, the switching switch 25 is provided at the subsequent stage of the DSP 20. The acoustic signal processing device having such a configuration cannot absorb the influence of the delay time of the SRCs 21 and 22 and cannot be said to be very efficient.

[0034] [Example 4]

FIG. 5 is a block diagram of the acoustic signal processing apparatus according to the fourth embodiment. In the acoustic signal processing apparatus of the present embodiment, the switching switch 25 is provided at the subsequent stage of the DFs 31 and 32. In the acoustic signal processing apparatus having such a configuration, not only the delay time of the SRCs 21 and 22 but also the influence of the delay time of the DFs 31 and 32 can be absorbed. Therefore, the phase shift can be reduced more efficiently than in the first embodiment.

In this embodiment, the power of using two DSPs for each of the A channel path 30 and the B channel path 40 may be one DSP for each of these paths. In this case, the signal digitally filtered by DF31 or 32 is input to the DSP without being branched, and is output to the antiphase terminal and the positive phase terminal in the antiphase or positive phase. In the acoustic signal processing apparatus according to the present embodiment, when trying to obtain a balanced output with the same output destination band of both systems, either the positive terminal output or the negative terminal output of the Norrance output is 1 Since the signal of one system branched into two is output, at least at the time of the switching means, there can be no phase shift. As a result, the phase of the output signal finally output to the positive terminal output and negative terminal output The difference can be made extremely small.

Industrial applicability

As described above, the acoustic signal processing apparatus according to the present invention is preferably applied to a digital signal processing unit of an audio master amplifier or a slave amplifier.

Claims

The scope of the claims

[1] A signal processing unit that performs predetermined signal processing on the input acoustic signal, and then outputs at least two signals of system A and system B;

The A system and B system signals are input to generate a positive phase signal and an antiphase signal, and output to the positive phase terminal and the antiphase terminal, respectively. And

Either the positive phase terminal or the negative phase terminal and the ground terminal are selected for unbalanced output, or the terminals of different phases of the A system and B system are selected for balanced output. In the acoustic signal processing apparatus that can be used, the determination means for determining whether the output destination bands of the A system and the B system are the same, and the A system signal path When the bands of both systems are different based on the judgment of the judgment means provided between the B system signal paths, the signals of both systems are output to the respective positive phase terminals and the opposite phase terminals, respectively. When the bands of both systems are the same, the switching means for branching the signal of either one of the two systems of system A and system B into two and outputting to the other positive phase terminal and opposite phase terminal,

An acoustic signal processing device comprising:

[2] The A system and B system signal paths perform independent signal processing.

The acoustic signal processing device according to claim 1, further comprising:

[3] The signal processing unit inputs a digital signal, performs digital signal processing, and outputs a digital signal.

The system A and system B signal paths include a digital-analog converter, which inputs the digital signal and outputs an analog signal.

The acoustic signal processing device according to claim 1 or 2, wherein

[4] The A-system and B-system signal paths each have a frequency converter, and the switching means is provided at the subsequent stage of the frequency converter.

The acoustic signal processing device according to any one of claims 1 to 3, wherein