CN112995848A

CN112995848A - Audio processing circuit and audio processing method

Info

Publication number: CN112995848A
Application number: CN201911212455.9A
Authority: CN
Inventors: 杜博仁; 张嘉仁; 曾凯盟
Original assignee: Acer Inc
Current assignee: Acer Inc
Priority date: 2019-12-02
Filing date: 2019-12-02
Publication date: 2021-06-18
Anticipated expiration: 2039-12-02
Also published as: CN112995848B

Abstract

The embodiment of the invention provides an audio processing circuit and an audio processing method, which are suitable for processing signals input to a loudspeaker, and the loudspeaker is configured with rated power. The audio processing circuit includes, but is not limited to, an audio generator and a power regulator. The audio generator provides an audio signal, and the audio signal includes a high frequency signal and a medium and low frequency signal. The power regulator is electrically coupled with the audio generator and regulates the power of the high-frequency signal without regulating the power of the medium-low frequency signal according to the enhanced power. The boosted power is greater than the rated power and the output signal of the power regulator is for input to the speaker. Therefore, the transmission distance of the high-frequency signal can be increased.

Description

Audio processing circuit and audio processing method

Technical Field

The present invention relates to signal processing technologies, and in particular, to an audio processing circuit and an audio processing method.

Background

The prior art has delivered additional information (e.g., configuration settings, authentication codes, device information, etc.) via high frequency signals in the acoustic signal (e.g., signals having frequencies above 18 kilohertz (kHz)). The human ear is generally not able to hear these high frequency signals. Notably, the energy of high frequency signals decays faster with increasing propagation distance than medium and low frequency signals (e.g., signals below a frequency of 18 kHz). While the power rating of a speaker (or speaker) unit equipped in most mobile devices (e.g., mobile phones, tablet computers, handheld game consoles, etc.) or some electronic devices (e.g., displays, notebook computers, etc.) is usually not high (e.g., about 2 watts (W)).

Fig. 1 is an architecture diagram of a conventional mobile device. Referring to fig. 1, when a conventional mobile device plays an Audio signal through an Application program (Application), before the Audio signal reaches a speaker, a scale gain is adjusted through an Audio Engine (Audio Engine), and finally the Audio signal is amplified through a hardware power amplifier for the speaker to play. To ensure that the output signal meets the rated power (e.g., 2W) limit of the speaker cell, the designer would adjust the gain of the power amplifier to make the output power not greater than the rated power of the speaker cell when the maximum sound source (e.g., 0 decibel versus full scale (dBFS)) is played and the maximum scale (e.g., scale gain of 1) is reached.

It is necessary to increase the output power of the power amplifier in the device if the acoustic signal is to be used for more beneficial applications. However, if the output power of the power amplifier is simply increased to exceed the rated power limit of the speaker unit, the sound signal with increased power is input to the speaker unit, which inevitably causes the risk of burning out the speaker unit.

Disclosure of Invention

In view of the above, embodiments of the present invention provide an audio processing circuit and an audio processing method, which amplify output power of a high frequency signal in a sound signal within a power safety range.

The audio processing circuit of the embodiment of the invention is suitable for processing signals input to a loudspeaker, and the loudspeaker is configured with rated power. The audio processing circuit includes, but is not limited to, an audio generator and a power regulator. The audio generator provides an audio signal, and the audio signal includes a high frequency signal and a medium and low frequency signal. The power regulator is electrically coupled with the audio generator and regulates the power of the high-frequency signal without regulating the power of the medium-low frequency signal according to the enhanced power. The boosted power is greater than the rated power and the output signal of the power regulator is for input to the speaker.

In another aspect, an audio processing method of an embodiment of the present invention is adapted to process a signal input to a speaker, and the speaker is configured with a rated power. The audio processing method comprises the following steps: an audio signal is generated, and the audio signal includes a high frequency signal and a medium and low frequency signal. The power of the high frequency signal is adjusted according to the enhanced power without adjusting the power of the medium and low frequency signals. The boost power is greater than the rated power, and the high frequency signal is used for inputting to the loudspeaker after the boost power is adjusted. The intermediate and low frequency signals are provided with static gain according to the amplified power. The static gain is limited to the rated power relative to the maximum power of the middle and low frequency signals after being amplified by the amplifying power.

Based on the above, the audio processing circuit and the audio processing method according to the embodiments of the present invention increase the output power of the high-frequency signal in the sound signal to be higher than the rated power of the speaker and within the power safety range of the speaker. In addition, the output power of the medium and low frequency signals in the sound signals can be limited within the rated power. Therefore, the transmission distance of the high-frequency signal can be increased, the data error rate can be reduced, and the monomer can be prevented from being burnt.

In order to make the aforementioned and other features of the invention more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

FIG. 1 is an architecture diagram of a prior art mobile device;

FIG. 2 is a block diagram of the audio processing circuit according to an embodiment of the present invention;

FIG. 3 is a flow chart of an audio processing method according to an embodiment of the invention;

FIG. 4 is a block diagram of the components of an audio processing circuit according to an embodiment of the invention;

FIG. 5 is a graph of scale gain versus dynamic gain according to one embodiment of the present invention;

FIG. 6 is a block diagram of the components of an audio processing circuit according to an embodiment of the invention;

FIG. 7 is a frequency response graph of a filter according to an embodiment of the invention;

FIG. 8 is a block diagram of audio processing circuitry according to an embodiment of the present invention.

Description of the reference numerals

50: loudspeaker

100. 100-1, 100-2: audio processing circuit

110. 110-1, 110-3: audio generator

111: high frequency signal generator

1112: general signal generator

130. 130-1, 130-2, 130-3: power regulator

131: dynamic gain adjusting circuit

132: filter with a filter element having a plurality of filter elements

133: scale gain circuit

134: static gain adjusting circuit

135: power amplifier

S310 to S330: step (ii) of

AS: sound signal

OS, OS1, OS 2: output signal

HFS, HFS 2: high frequency signal

NAS, NAS 2: middle and low frequency signal

FS: first signal

And SS: second signal

CS: combined signal

c: dynamic gain

a: ratio of boost power to rated power

X: rated power

Y: amplifying power

g: gain of scale

Fs: sampling frequency

R: frequency range

H (f): frequency response

Detailed Description

Fig. 2 is a block diagram of the audio processing circuit 100 according to an embodiment of the invention. Referring to fig. 2, the audio processing circuit 100 includes, but is not limited to, an audio generator 110 and a power regulator 130. The audio processing circuit 100 may be disposed in an electronic device such as a mobile phone, a tablet computer, a notebook computer, an All-in-One (AIO) computer, an intelligent speaker, an intelligent appliance, and the like. The audio processing circuit 100 may be connected to a speaker 50, such as a speaker, a loudspeaker, etc., for playing sound.

The audio generator 110 may be implemented by a Central Processing Unit (CPU), or other Programmable general purpose or special purpose Microprocessor (Microprocessor), Digital Signal Processor (DSP), Field Programmable Gate Array (FPGA), Programmable controller, Application-Specific Integrated Circuit (ASIC), or other similar components or combinations thereof. In some embodiments, the audio generator 110 may be comprised of one or more digital circuits.

The power regulator 130 is electrically coupled to the audio generator 110, and the power regulator 130 may include one or more digital or analog circuits. These circuits may be power amplifiers, gain adjustment circuits, etc. In one embodiment, the power regulator 130 may be electrically coupled to the speaker 50 and play its output signal OS through the speaker 50.

To facilitate understanding of the operation flow of the embodiment of the present invention, the operation flow of the audio processing circuit 100 in the embodiment of the present invention will be described in detail below with reference to various embodiments. Hereinafter, the method according to the embodiment of the present invention will be described with reference to the devices in the audio processing circuit 100. The various processes of the method may be modified according to implementation, and are not limited thereto.

Fig. 3 is a flowchart of an audio processing method according to an embodiment of the invention. Referring to fig. 3, the audio generator 110 generates an audio signal AS (step S310). Specifically, such an acoustic signal AS may comprise a high frequency signal, e.g., having a frequency exceeding a certain threshold (e.g., 18, 20, or 25 kilohertz (kHz)), or a combination of a high frequency signal and a medium-low frequency signal, e.g., having a frequency below a certain threshold (e.g., 18, 20, or 25 kHz). For example, the frequency band of the high frequency signal is 18-24 kHz. The high frequency signal may include information or data such as configuration, device information, instructions and/or update files, and the medium and low frequency signals may be various types of sound signals such as music, lecture, audio book, etc., which should not be limited by the embodiments of the present invention. Note that the sound signal AS can be assumed to be at the maximum sound source (0 dBFS).

The power adjuster 130 receives the audio signal AS and adjusts the power of the high frequency signal in the audio signal AS according to the enhanced power (step S330). Specifically, assume that the speaker 50 is configured with a particular power rating (e.g., 2, 4, or 8 watts (W), etc.). It is noted that the power rating of the speaker 50 alone is primarily the protection mechanism for this speaker 50 for all frequency signals. It has been observed experimentally that even if the energy of the high frequency signal exceeds the rated power by a few (e.g., 1, 2, or 4W, etc.), the speaker 50 is not suspected of burning out because the high frequency signal fluctuates rapidly. Based on this experimental result, one of the inventive concepts of the embodiments of the present invention is to amplify the energy of the high frequency signal to exceed the rated power of the speaker 50 alone. The maximum output power of the high frequency signal (assuming a maximum source (e.g., 0dBFS) and being the maximum scale (e.g., scale gain being 1 and being the maximum)) is defined as the boost power in the present embodiment, and its ratio to the overall rated power is a (greater than 1) (i.e., the boost power is greater than the rated power).

In one embodiment, the boost power may be the maximum power that the speaker 50 can carry at half the sampling frequency of the audio signal AS, considering the power safety range of the speaker 50 alone. In another embodiment, the boost power may be set to any of the aforementioned power safety ranges. In other embodiments, the value of the boost power may vary depending on the material or component of the cell.

Therefore, for high-frequency signals, the output power of the embodiment of the invention is increased, and the output power can exceed the rated power of the loudspeaker 50 alone. The output signal OS of the power regulator 130 is input to the speaker 50 and played through the speaker 50, which effectively increases the transmission distance of the high frequency signal and improves the error rate.

To assist the reader in understanding the inventive concepts of the embodiments of the present invention, several additional embodiments are described below.

Fig. 4 is a block diagram of the audio processing circuit 100-1 according to an embodiment of the invention. Referring to fig. 4, the audio generator 110-1 of the audio processing circuit 100-1 includes a high frequency signal generator 111. The high frequency signal generator 111 is used to generate a high frequency signal HFS.

The power regulator 130-1 includes a dynamic gain adjustment circuit 131, a scale gain circuit 133, and a power amplifier 135. The dynamic gain adjustment circuit 131 is electrically coupled between the audio generator 110-1 and the scale gain circuit 133, and receives the high frequency signal HFS output by the audio generator 110-1, and provides a dynamic gain for the high frequency signal HFS to output the first signal FS, wherein the determination of the dynamic gain is described in detail later.

The scale gain circuit 133 is electrically coupled between the dynamic gain adjustment circuit 131 and the power amplifier 135, and provides a scale gain corresponding to the scale setting operation to the first signal FS in response to the scale setting operation to output the second signal SS. Assuming that the scale gain is adjustable by the user, the power adjuster 130-1 sets the scale gain based on the scale setting operation of the user on the scale gain received by the input device (e.g., a button, a dial, a mouse, etc.). For example, a clockwise rotation of the dial by one step of the scale setting operation may correspond to a step up of the scale. In one embodiment, the scale gain is a value between 0 and 1, i.e., the maximum scale gain is 1 (the minimum scale gain may be 0 or other values).

In addition, the power amplifier 135 is configured with an amplification power (assuming the case of a maximum sound source (e.g., 0dBFS) and a maximum scale gain), and provides this amplification power to the second signal SS to output an output signal OS 1. The amplification power of the power amplifier 135 is not less than the boosting power, compared to the case where the output power of the conventional power amplifier is set to the rated power of the speaker 50. For example, the rated power is 2W and the amplification power is 6W (i.e., the power safety range of the speaker 50 alone (e.g., 3.5-4W)) may be exceeded). Power amplifier 135 may also provide its output signal OS1 to speaker 50.

It should be noted that the user may adjust the scale such that the energy of the high frequency signal HFS is reduced. If the high frequency signal HFS is maintained at the maximum volume level as much as possible and the high frequency signal HFS is transmitted over a longer distance, the dynamic gain may be inversely related to the scale gain. In one embodiment, the dynamic gain can be derived from equation (1):

where c is the dynamic gain, a is the ratio of the boosted power to the rated power, X is the rated power, Y is the amplified power, and g is the scale gain.

FIG. 5 is a graph of scale gain versus dynamic gain according to one embodiment of the present invention. Referring to fig. 5, when the scale gain g is 1 to (aX)/Y, the dynamic gain c is inversely proportional to the scale gain g, and the output powers of the output signals OS1 are all aX (i.e., enhanced powers). It is noted that if the scale gain is too small, the dynamic gain will be larger than 1 and cause signal clipping (clipping) problems. Therefore, the condition that the dynamic gain is inversely proportional to the scale gain is limited to the case where the scale gain is greater than (aX)/Y. If the scale gain is not greater than (aX)/Y, the dynamic gain remains 1 (or other constant) such that the output power of the output signal OS1 is gY.

FIG. 6 is a block diagram of the audio processing circuit 110-2 according to an embodiment of the invention. Referring to fig. 6, the difference between the embodiment of fig. 5 and the power regulator 130-2 of the audio processing circuit 110-2 is that the power regulator further includes a filter 132. Unlike the conventional filter which mainly uses the passband, the embodiment of the present invention mainly uses the transition band, and the filter 132 matches the power corresponding to the transition band of the high frequency signal HFS with the power safety range of the speaker 50 alone (assuming between the rated power and the enhanced power).

Fig. 7 is a graph of the frequency response (h (f)) of the filter 132 according to an embodiment of the invention. Referring to FIG. 7, the high frequency signal HFS uses a frequency range R (e.g., 18 kHz-24 kHz (half of the sampling frequency Fs)). The transition band of the high pass filter 132 may be configured to include 18kHz to 24kHz, which may correspond to different power safety ranges (e.g., 3.5W-4W) of the speaker 50, so that the attenuation characteristic of the high frequency signal HFS2 output by the high pass filter 132 may meet the power safety range requirement to ensure that each frequency of the high frequency signal HFS is not at risk of burning out the speaker.

Fig. 8 is a block diagram of the audio processing circuit 100-3 according to an embodiment of the invention. Referring to fig. 8, the difference from the embodiment of fig. 6 is that the audio generator 110-3 of the audio processing circuit 100-3 further includes a general signal generator 1112, and the power adjuster 130-2 further includes a static gain adjusting circuit 134 and a summing circuit 137 (e.g., a summing circuit, or a programmable gain amplifier).

The general signal generator 1112 is configured to generate the low and medium frequency signal NAS. The static gain adjustment circuit 134 is electrically coupled between the general signal generator 1112 of the audio generator 110-3 and the power amplifier 135. The static gain adjusting circuit 134 receives the low and medium frequency signal NAS outputted from the general signal generator 1112, and provides a fixed static gain according to the amplified power of the power amplifier 135. It should be noted that, in order to make the final output power of the middle-low frequency signal NAS not exceed the rated power (if the final output power exceeds the rated power, there may be a risk of burning out the single body), the static gain is limited to the rated power with respect to the maximum power of the middle-low frequency signal NAS amplified by the power amplifier 135 (for example, the maximum value is not greater than the rated power). For example, the static gain may be set to a ratio of the rated power to the amplification power (i.e., X/Y) so that the mid-low frequency signal NAS maintains its output power at the rated power (i.e., X) with the largest sound source and at the largest scale.

On the other hand, considering that the middle and low frequency signal NAS is normally played while information is transmitted by the high frequency signal HFS, the summing circuit 137 sums/superimposes the middle and low frequency signal NAS2 (the signal output by the static gain adjustment circuit 134) and the first signal FS output by the dynamic gain adjustment circuit 131 to generate the combined signal CS. The scale gain circuit 133 adjusts the combined signal CS according to the scale gain. Finally, the output signal OS2 output by the power amplifier 135 may include the contents of the low and medium frequency signal NAS and the high frequency signal HFS.

In summary, the audio processing circuit and the audio processing method according to the embodiments of the present invention increase the output power of the high-frequency signal for transmitting data, and meet the safety range of the single body, thereby increasing the transmission distance of the high-frequency signal and avoiding the risk of burning the single body. In addition, the high frequency signal can be maintained at an increased power with the change of the scale, but the problem of signal clipping can be avoided. It is further noted that, in addition to outputting high frequency signals, the audio processing circuit can also output low and medium frequency signals simultaneously. Therefore, the loudspeaker can normally play music under the condition of meeting the rated power.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. An audio processing circuit adapted to process a signal input to a speaker, wherein the speaker is configured with a rated power, the audio processing circuit comprising:

an audio generator providing a sound signal, wherein the sound signal comprises a high frequency signal and a medium and low frequency signal; and

a power regulator electrically coupled to the audio generator and adjusting the power of the high frequency signal without adjusting the power of the medium and low frequency signals according to an enhanced power, wherein the enhanced power is greater than the rated power, and an output signal of the power regulator is used for being input to the speaker.

2. The audio processing circuit of claim 1, wherein the power regulator comprises:

a power amplifier configured with an amplified power, wherein the amplified power is not less than the boost power, and the power amplifier is for providing its output signal to the speaker;

a scale gain circuit electrically coupled to the power amplifier and providing a scale gain corresponding to the scale setting operation in response to the scale setting operation;

a dynamic gain adjustment circuit electrically coupled between the audio generator and the scale gain circuit, receiving the high frequency signal output by the audio generator, and providing a dynamic gain to the high frequency signal according to the scale gain, wherein the dynamic gain is related to an inverse ratio of the scale gain; and

the static gain adjusting circuit is electrically coupled between the audio generator and the power amplifier, receives the medium and low frequency signals output by the audio generator, and provides a static gain according to the amplification power, wherein the static gain is limited to the rated power relative to the maximum power of the medium and low frequency signals amplified by the power amplifier.

3. The audio processing circuit of claim 2, wherein the dynamic gain is

Wherein c is the dynamic gain, a is a ratio of the enhancement power to the rated power, X is the rated power, Y is the amplification power, and g is the scale gain, wherein a maximum value of the scale gain is 1.

4. The audio processing circuit of claim 1, wherein the power regulator comprises:

and the filter is electrically coupled with the audio generator and conforms the power corresponding to the excess frequency band of the high-frequency signal to the power safety range of the loudspeaker, wherein the power safety range is between the rated power and the enhanced power.

5. The audio processing circuit of claim 1, wherein the boost power is a maximum power that the speaker can carry at half a sampling frequency of the sound signal.

6. An audio processing method adapted to process a signal input to a speaker, wherein the speaker is configured with a rated power, the audio processing method comprising:

generating a sound signal, wherein the sound signal comprises a high frequency signal and a medium and low frequency signal;

adjusting the power of the high-frequency signal according to an enhanced power without adjusting the power of the medium-low frequency signal, wherein the enhanced power is larger than the rated power, and the high-frequency signal is used for being input to the loudspeaker through the signal adjusted by the enhanced power; and

and providing static gain for the medium and low frequency signals according to the amplification power, wherein the static gain is limited to the rated power relative to the maximum power of the medium and low frequency signals amplified by the amplification power.

7. The audio processing method according to claim 6, wherein the step of adjusting the power of the high frequency signal in dependence on the boost power comprises:

providing a dynamic gain to the high frequency signal to output a first signal;

providing a scale gain corresponding to a scale setting operation to the first signal in response to the scale setting operation to output a second signal, wherein the dynamic gain is related to an inverse proportion of the scale gain; and

providing the amplified power to the second signal to output an output signal, wherein the output signal is for providing to the speaker.

8. The audio processing method according to claim 7, wherein the dynamic gain is

9. The audio processing method of claim 6, further comprising:

and conforming the power corresponding to the transition frequency band of the high-frequency signal to the power safety range of the loudspeaker, wherein the power safety range is between the rated power and the enhanced power.

10. The audio processing method of claim 6, wherein the boost power is a maximum power that the speaker can carry at half of a sampling frequency of the sound signal.