JP2011228858A - Audio signal processing apparatus and audio signal processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an audio signal processing apparatus capable of improving combinational effects of a general-purpose speaker and a speaker dedicated for low frequency bands.SOLUTION: The audio signal processing apparatus comprises: signal processing means for generating a first signal corresponding to a first frequency range component and a second signal corresponding to a second frequency range component from an input audio signal in response to characteristics of a first speaker for reproducing the first frequency range component; detection means for detecting connection of the first speaker; and output means for outputting the second signal to a second speaker in response to detection of the first speaker.

Description

  Embodiments described herein relate generally to an audio signal processing apparatus and audio signal processing that generate a low-frequency component signal and a mid-high frequency component signal from an input audio signal.

  A woofer or a subwoofer is known as a low-frequency speaker. Compared to the case where an input audio signal including the entire range component is output with only one general-purpose speaker, the general-purpose speaker and subwoofer are used together, and the low-frequency component is output with the subwoofer to enjoy more powerful bass. be able to.

Japanese Patent Laid-Open No. 08-116586

  When a general-purpose speaker and a subwoofer are used in combination, bass sound is reproduced by the subwoofer, but bass sound is also reproduced by the general-purpose speaker. In such a combination environment of a general-purpose speaker and a subwoofer, it is difficult to sufficiently obtain a combined effect of the general-purpose speaker and the subwoofer.

  An object of the present invention is to provide an audio signal processing device and an audio signal processing method capable of improving the combined effect of, for example, a general-purpose speaker and a low-frequency range dedicated speaker.

  The audio signal processing apparatus according to the embodiment includes a first signal corresponding to the first sound range component and a second signal corresponding to the first sound range component from an input audio signal according to the characteristics of the first speaker for reproducing the first sound range component. Signal processing means for generating a second signal corresponding to a sound range component, detection means for detecting connection of the first speaker, and second signal in response to detection of the first speaker. Output means for outputting to the speaker.

It is a block diagram which shows an example of the audio signal processing apparatus of this embodiment. It is a flowchart which shows an example of 1st signal processing. It is a flowchart which shows an example of 2nd signal processing.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram illustrating an example of an audio signal processing apparatus according to the present embodiment. For example, the audio signal processing apparatus 10 can be applied to a digital TV.

  As shown in FIG. 1, an audio signal processing apparatus 10 includes an audio signal input unit 11, an audio signal processing module 12, a digital power amplifier 13, a built-in speaker (second speaker) 14, a subwoofer D / A converter 15, and a subwoofer. An output unit 16, a detection module 17, and a control module 18 are provided.

  The audio signal processing device 10 is configured to be connectable to the first low sound region output device 20 (first speaker) or the second low sound region output device 30 via the subwoofer output unit 16. The first bass output device 20 is a dedicated subwoofer, for example, and includes a selector 21, a filter 22, a power amplifier 23, and a speaker 24. One second bass output device 30 is, for example, a normal subwoofer, and includes a filter 32, a power amplifier 33, and a speaker 34.

  The first low-frequency output device 20 is a speaker specialized for outputting low-frequency components. For example, the selector 21 of the first low-frequency output device 20 includes a low-frequency component (first sound range component) and a mid-high sound. In response to the input of the entire range audio signal including the range component (second range component), the entire range audio signal is output to the filter 22. The filter 22 cuts off the mid-high range component of this whole range audio signal. In other words, the filter 22 extracts a low frequency range component from this whole range audio signal. The power amplifier 23 amplifies the extracted low-frequency component, and the speaker 24 outputs the amplified low-frequency component. Further, the selector 21 of the first low frequency range output device 20 outputs this low frequency range component to the power amplifier 23 in response to the input of the low frequency range component (first sound range component). The power amplifier 23 amplifies the low frequency range component, and the speaker 24 outputs the amplified low frequency range component. For example, the selector 21 detects the input of the whole range audio signal or the low range component signal based on the input signal component, and outputs the full range audio signal to the filter 22 when the full range audio signal is detected. When the component signal is detected, the low frequency range component is output to the power amplifier 23.

  On the other hand, the second low-frequency output device 30 is also a speaker specialized in outputting low-frequency components. For example, the filter 32 of the second low-frequency output device 30 can detect low-frequency components from the input whole-range audio signal. The power amplifier 33 amplifies the extracted low-frequency component, and the speaker 34 outputs the amplified low-frequency component.

  That is, the first low-frequency output device 20 is configured to be able to handle both the input of the whole-range audio signal and the input of the low-frequency component as described above, and passes through the filtering process when the low-frequency component is input. be able to. The second low frequency range output device 30 is configured to be compatible with the input of the full range audio signal.

  The audio signal processing device 10 will be described on the assumption that the audio signal processing device 10 is configured to be connectable to the first low frequency range output device 20 or the second low frequency range output device 30 having the above-described configuration. To do.

  The detection module 17 is configured to be able to detect whether a speaker is connected or not connected to the subwoofer output unit 16, and further, the type of speaker connected to the subwoofer output unit 16 and At least one of the characteristics can be detected. The detection module 17 connects the first low-frequency output device 20 to the subwoofer output unit 16 or the second low-frequency output device to the subwoofer output unit 16 according to the detection result of at least one of the speaker type and characteristics. 30 connections can be detected.

  For example, the detection module 17 is configured by a switch, and can detect at least one of the type and characteristics of the speaker and further can detect that the speaker is not connected based on the setting of the switch. That is, the detection module 17 can detect the connection of the first low-frequency output device 20, the connection of the second low-frequency output device 30, or the speaker not connected.

  Alternatively, the detection module 17 detects at least one of the type and characteristics of the speaker based on a control signal input via HDMI (High-Definition Multimedia Interface), and further detects that the speaker is not connected. can do. That is, the detection module 17 can detect the connection of the first low-frequency output device 20, the connection of the second low-frequency output device 30, or the speaker not connected.

  Or the detection module 17 can detect at least one of the kind and characteristic of a speaker based on the speaker setting information input via the setting screen etc., and also can detect the speaker non-connection. . That is, the detection module 17 can detect the connection of the first low-frequency output device 20, the connection of the second low-frequency output device 30, or the speaker not connected.

  The detection method of detecting the connection of the first low-frequency output device 20, the connection of the second low-frequency output device 30, or the unconnected speaker by the detection module 17 is not limited to the above, and various other methods can be used. Can be applied.

  The control module 18 is notified of the detection result of the connection of the first low-frequency output device 20, the connection of the second low-frequency output device 30, or the unconnected speaker by the detection module 17. The control module 18 can be composed of, for example, a CPU (Central Processing Unit). The control module 18 is an audio signal processing module according to the connection result of the first low-frequency output device 20, the connection of the second low-frequency output device 30, or the detection result of the unconnected speaker and the characteristics of the built-in speaker 14. 12 signal processing is controlled.

  The audio signal processing module 12 can be configured by an audio DSP (Digital Signal Processor). For example, the audio signal processing module 12 includes a band limiting circuit, and according to the signal processing control of the control module 18, the audio signal processing module 12 has a band for the input audio signal (full range audio signal) input via the audio signal input unit 11. Perform restriction processing. For example, the audio signal processing module 12 responds to the signal processing control of the control module 18, and the first signal corresponding to the low frequency range component (first frequency range component) and the middle and high frequency range components (first frequency range) from the whole range audio signal. The second signal corresponding to the second sound range component) can be generated.

  For example, the audio signal processing module 12 does not simply separate a predetermined low-frequency component and a predetermined medium-high frequency component from the whole-range audio signal, but the first low-frequency output device 20 or the second low-frequency output device 20. The first signal corresponding to the low frequency range component (first frequency range component) and the middle and high frequency range components (second frequency range) from the whole range audio signal according to the characteristics of the range output device 30 and the characteristics of the built-in speaker 14. The second signal corresponding to the component) can be generated. That is, the audio signal processing module 12 has the first signal and the second signal optimized according to the characteristics of the first low-frequency output device 20 or the second low-frequency output device 30 and the characteristics of the built-in speaker 14. The signal can be generated.

  Further, the audio signal processing module 12 selectively executes the first, second, and third output processes according to the signal processing control of the control module 18. The first output process is a process of outputting the optimized first signal to the subwoofer DA converter 15 and outputting the optimized second signal to the digital power amplifier 13. The second output process is a process of outputting the whole-range audio signal to the subwoofer DA converter 15 and outputting the optimized second signal to the digital power amplifier 13. The third output process is a process for outputting the whole-range audio signal to the digital power amplifier 13.

  For example, when the control module 18 receives a notification of connection detection of the first bass output device 20 from the detection module, the control module 18 notifies the audio signal processing module 12 of the selection of the first output process. As a result, the audio signal processing module 12 selects the first output process, outputs the optimized first signal to the subwoofer DA converter 15, and outputs the optimized second signal to the digital power. Output to the amplifier 13.

  The digital power amplifier 13 amplifies the optimized second signal corresponding to the input of the optimized second signal, and the built-in speaker 14 outputs the amplified second signal. The subwoofer DA converter 15 converts the optimized first signal from a digital signal to an analog signal in response to the input of the optimized first signal, and the subwoofer output unit 16 outputs the analog signal. The first signal converted into is output. In this case, as described above, the first bass output device 20 is connected via the subwoofer output unit 16, and the first bass output device 20 receives the first signal. (Ie, corresponding to the input of the low frequency range component), the first signal is output from the speaker 24 via the power amplifier 23. That is, the first bass output device 20 outputs the first signal from the speaker 24 without passing through the filter 22.

  When the control module 18 receives a notification of connection detection of the second bass output device 30 from the detection module, the control module 18 notifies the audio signal processing module 12 of the selection of the second output process. As a result, the audio signal processing module 12 selects the second output process, outputs the entire range audio signal to the subwoofer DA converter 15, and outputs the optimized second signal to the digital power amplifier 13. To do.

  The digital power amplifier 13 amplifies the optimized second signal corresponding to the input of the optimized second signal, and the built-in speaker 14 outputs the amplified second signal. Further, the subwoofer DA converter 15 converts the entire sound range audio signal from a digital signal to an analog signal in response to the input of the entire sound range audio signal, and the subwoofer output unit 16 converts the entire sound range audio signal into the analog signal. Is output. In this case, as described above, the second bass output device 30 is connected via the subwoofer output unit 16, and the second bass output device 30 is connected to the full-range audio by the filter 32. A low-frequency component is extracted from the signal, the low-frequency component is amplified by the power amplifier 33, and the low-frequency component is output by the speaker 34.

  In addition, when receiving a notification that the speaker is not connected from the detection module, the control module 18 notifies the audio signal processing module 12 of the selection of the third output process. As a result, the audio signal processing module 12 selects the third output process and outputs the full-range audio signal to the digital power amplifier 13.

  The digital power amplifier 13 amplifies the full-range audio signal in response to the input of the full-range audio signal, and the built-in speaker 14 outputs the amplified full-range audio signal.

  As described above, the audio signal processing device can output an appropriate signal according to the connection of the first low-frequency output device 20, the connection of the second low-frequency output device 30, or the speaker not connected. For example, the built-in speaker 14 outputs a first case of outputting an audio signal (middle and high range component) in which the low frequency range component is blocked, and a second case of outputting an audio signal (full range component) that does not block the low range component. In comparison with the case, the built-in speaker 14 can reproduce the mid-high range component with higher quality in the first case than in the second case. That is, the built-in speaker 14 can reproduce the mid-high range component with high quality by the first output process or the second output process described above. In other words, a sufficient combined effect of the built-in speaker 14 and the first low sound range output device 20 or the second low sound range output device 30 can be obtained by the first output process or the second output process.

  Next, an example of the first signal processing will be described with reference to FIG. As shown in FIG. 2, when the detection module 17 detects a subwoofer setting, that is, detects that a subwoofer is connected (ST101) (ST102, YES), the audio signal processing module 12 performs all of the subwoofer setting detections. The low-frequency range component obtained by blocking the mid-high frequency range component from the range audio signal is output to the subwoofer DA converter 15 (ST103), and the full-range audio signal is output to the digital power amplifier 13. As a result, the low frequency range component is output by the subwoofer, but the full range audio signal (including the low frequency range component) is also output by the built-in speaker 14.

  When the detection module 17 detects that the subwoofer is not set, that is, detects that the subwoofer is not connected (ST101) (ST102, NO), the audio signal processing module 12 digitally converts the entire range audio signal based on the detection of the subwoofer not set. Output to the power amplifier 13. That is, the low frequency range component obtained by blocking the middle and high frequency range components is not output to the subwoofer DA converter 15 (ST104).

  For example, even if the built-in speaker 14 is a speaker having a low low-frequency range reproduction capability, in the first signal processing described above, the built-in speaker 14 always has a low-frequency component (regardless of the connection of the subwoofer). The audio signal (full range component) that is not interrupted is output. Thereby, the output quality from the built-in speaker 14 may deteriorate, and as a result, the combined effect of the built-in speaker 14 and the subwoofer may be reduced.

  Next, an example of the second signal processing will be described with reference to FIG. As shown in FIG. 3, when the detection module 17 detects the subwoofer setting, that is, when the subwoofer connection is detected (ST201) (ST202, YES), the audio signal processing module 12 performs all the subwoofer setting detections. From the sound range audio signal, the low sound range component obtained by blocking the middle and high sound range components is output to the subwoofer DA converter 15 (ST203). When the detection module 17 detects that the subwoofer is not set, that is, detects that the subwoofer is not connected (ST201) (ST202, NO), the audio signal processing module 12 digitally converts the entire range audio signal based on the detection of the subwoofer not set. The low-frequency component output from the power amplifier 13 and cut off the mid-high frequency component is not output to the subwoofer DA converter 15 (ST204).

  Furthermore, when the detection module 17 detects the dedicated subwoofer (first low frequency output device 20) (ST205) (ST206, YES), the audio signal processing module 12 determines the characteristics of the dedicated subwoofer and the built-in speaker. According to the 14 characteristics, the optimized first signal (low-frequency component in which the mid-high frequency component of the whole-range audio signal is cut off) and the optimized second signal (low-range audio signal low The first signal that has been generated and optimized is output from the dedicated subwoofer via the subwoofer DA converter 15, and the second signal that has been optimized is a digital signal. It is output from the built-in speaker 14 via the power amplifier 13 (ST207) (ST208).

  When the detection module 17 does not detect any subwoofer (ST202, NO) (ST206, NO), the audio signal processing module 12 outputs the full-range audio signal to the digital power amplifier 13 and outputs the mid-high range component. Is not output to the subwoofer DA converter 15 (ST209).

  When the detection module 17 does not detect the dedicated subwoofer but detects the normal subwoofer (ST202, YES) (ST206, NO), the audio signal processing module 12 converts the entire range audio signal into the digital power amplifier 13. And output to the woofer DA converter 15. Alternatively, the audio signal processing module 12 outputs the mid-high range component from which the low range component is blocked to the digital power amplifier 13, and outputs the entire range audio signal to the woofer DA converter 15.

  For example, assuming that the built-in speaker 14 is a speaker having a low low-frequency range reproduction capability, there is a concern that sound quality may be deteriorated by inputting a low-frequency component to the built-in speaker 14. For example, there is a concern about sound quality deterioration due to cabinet resonance, port noise, distortion, and the like. That is, even if the built-in speaker 14 and the dedicated subwoofer (first low-frequency output device 20) are used in combination, if the low-frequency component is input to the built-in speaker 14, the combined use of the built-in speaker 14 and the dedicated subwoofer is used. The effect will fade.

  As described above, in the second signal processing, when the dedicated subwoofer is connected, the mid-high range component in which the low range component is blocked (attenuated) is input to the built-in speaker 14, and the middle sub-woofer is Input a low-frequency component with the high-frequency component blocked (attenuated). Thereby, for example, the occurrence of cabinet resonance, port noise, distortion and the like can be suppressed, and a sufficient combined effect of the built-in speaker 14 and the dedicated subwoofer can be obtained. In addition, even when the normal subwoofer is connected, the mid-high range component in which the low range component is cut off can be input to the built-in speaker 14, so that the combined effect of the built-in speaker 14 and the dedicated subwoofer can be obtained.

  As described above, the audio signal processing apparatus can execute the second signal processing, and thereby, the role sharing between the built-in speaker 14 and the dedicated subwoofer can be clarified. In other words, the audio signal processing apparatus can leave the output of the middle and high sound range components to the built-in speaker 14 and leave the output of the low sound range components to the built-in speaker 14 by the second signal processing. As a result, the built-in speaker 14 reduces the output burden of the low-frequency component, can reduce the distortion of the output of the built-in speaker 14, can reduce cabinet resonance, and can ensure good sound quality.

  In addition, the audio signal processing device can output a low-frequency component with a band limited when detecting a connection of a subwoofer without a band limiting function, and can output an entire range audio signal without band limiting when detecting a connection of a subwoofer with a band limiting function. Can be output. In other words, the audio signal processing apparatus can output an appropriate signal according to the characteristics of the subwoofer.

  The module described above may be realized by hardware, or may be realized by software using a CPU or the like.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention in the implementation stage. In addition, the embodiments may be appropriately combined as much as possible, and in that case, the combined effect can be obtained. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some configuration requirements are deleted from all configuration requirements shown in the embodiment, if the problem described in the column of the problem to be solved by the invention can be solved, the configuration in which this configuration requirement is deleted Can be extracted as an invention.

DESCRIPTION OF SYMBOLS 10 ... Audio signal processing apparatus, 11 ... Audio signal input part, 12 ... Audio signal processing module, 13 ... Digital power amplifier, 14 ... Built-in speaker, 15 ... D / A converter for subwoofers, 16 ... Subwoofer output part, 17 ... Detection Module, 18 ... Control module

Claims (8)

According to the characteristics of the first speaker for reproducing the first sound range component, the first signal corresponding to the first sound range component and the second corresponding to the second sound range component are input from the input audio signal. Signal processing means for generating a signal;
Detecting means for detecting connection of the first speaker;
An output means for outputting the second signal to the second speaker in response to detection of the first speaker;
An audio signal processing apparatus comprising:   The audio signal processing apparatus according to claim 1, wherein the output unit outputs the first signal to the first speaker in response to detection of the first speaker.   2. The audio signal processing according to claim 1, wherein the output unit outputs a third signal corresponding to an input audio signal to the second speaker in response to the non-detection of the first speaker. 3. apparatus. The detection means is configured to extract the first sound range component from an input audio signal through a filtering process, and to reproduce the first sound range component, and the first type of the first speaker, and the filtering Detecting the second speaker of the second type out of the first speaker of the second type configured to be able to reproduce the first range component without processing,
The output means outputs the first signal to the first speaker and outputs the second signal to the second speaker in response to detection of the first speaker of the second type. To
The audio signal processing apparatus according to claim 1.   The audio signal processing apparatus according to claim 1, wherein the detection unit detects the first speaker based on input information indicating connection of the first speaker.   The output means outputs the second signal to the second speaker for reproducing the first sound range component and the second sound range component in response to detection of the first speaker. The audio signal processing apparatus according to claim 1.   The signal processing means determines the first sound range component and the second sound range component that is higher than the first sound range component according to the characteristics of the first speaker and the characteristics of the second speaker. The audio signal processing device according to claim 1, wherein the audio signal processing device is generated. According to the characteristics of the first speaker for reproducing the first sound range component, the first signal corresponding to the first sound range component and the second corresponding to the second sound range component are input from the input audio signal. Generate a signal,
An audio signal processing method for outputting the first signal to the first speaker and outputting the second signal to the second speaker in response to detection of the first speaker.

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