Patent Application
20130251158
1. Technical Field
The disclosure is directed to an audio signal measurement method for a speaker, and an electronic apparatus having the speaker, and more particularly to an electronic apparatus capable of self-testing a speaker thereof and an audio signal measurement method for the speaker.
2. Description of Related Art
In current modern society with increasingly developed multi-media, the quality of speakers is often one of the keys leading to virtue or vice of sounds heard by users. A speaker having bad quality usually results in a certain level of transducer distortion and acoustic box leakage. Conventionally, a microphone is usually used to test transducer distortion and acoustic box leakage for the speaker. However, such measurement method typically requires enough spaces and cost for installing an anechoic room and an acoustic analyzer. Thus, for the users, the conventional audio signal measurement method for the speaker in the related art will be difficult to put into use due to an obstacle to budgets and spaces that is difficult to overcome.
The disclosure is directed to an electronic apparatus capable of self-testing whether a speaker thereof is operated normally.
The disclosure is directed to an audio signal measurement method for a speaker, which is adopted to determining whether the speaker is operated normally.
The disclosure is directed to an audio signal measurement method for a speaker. The audio signal measurement method includes measuring a voltage value of an audio signal and measuring a current value of a current feedback from the speaker. The audio signal measurement method further includes executing a time domain to frequency domain transform according to the voltage value and the current value so as to obtain a frequency response curve. The audio signal measurement method yet further includes determining whether the frequency response curve falls within a predetermined area and sending out a signal if the frequency response curve falls out of the predetermined area.
The disclosure is directed to an electronic apparatus. The electronic apparatus includes a speaker, a processing circuit and a power amplifier. The speaker is configured to send out sounds. The processing circuit is coupled to the speaker and configured to execute a time domain to frequency domain transform according to a voltage value of an audio signal and a current value of a current feedback from the speaker so as to obtain a frequency response curve. The power amplifier is coupled to the speaker and configured to drive the speaker according the voltage value of the audio signal. Herein, the processing circuit is capable of determining whether the frequency response curve falls within a predetermined area and sending out a signal when the frequency response curve falls out of the predetermined area.
In one embodiment of the disclosure, the time domain to frequency domain transform is a Fourier transform.
In one embodiment of the disclosure, the Fourier transform is a fast Fourier transform (FFT).
In one embodiment of the disclosure, the time domain to frequency domain transform is a Laplace transform.
In one embodiment of the disclosure, the voltage value is represented by a time function v(t), the current value is presented by a time function i(t), and the frequency response curve is obtained by executing the time domain to frequency domain transform on [v(t)/i(t)], where t represents time.
In one embodiment of the disclosure, the voltage value is represented by the time function v(t), the current value is presented by the time function i(t), and the frequency response curve is obtained by executing the time domain to frequency domain transform on
where t represents time, Rdc is a resistor value of the driving device of the speaker under a normal room temperature, and B1 is a constant value of the speaker.
In one embodiment of the disclosure, the electronic apparatus further includes an augmenter, which is coupled to the processing circuit and configured to augment a source signal to generate the audio signal. When the frequency response curve falls out of the predetermined area, the processing circuit adjusts a gain for the audio signal.
In one embodiment of the disclosure, the frequency response curve is configured to present a relationship between an impedance of the speaker and a frequency of the sound sent from the speaker.
In one embodiment of the disclosure, the frequency response curve is configured to represent a relationship between a stroke of a diaphragm of the speaker and the frequency of the sound sent from the speaker.
To sum up, the electronic apparatus as described according to the embodiments of the disclosure may self-measure whether the speaker thereof meets desired requirements. Since neither an anechoic room nor an acoustic analyzer requires to be additionally installed, the usage convenience may be significantly enhanced, and the testing cost for the speaker may be lower down.
In order to make the aforementioned and other features and advantages of the disclosure more comprehensible, embodiments accompanying figures are described in detail below.
The accompanying drawings constituting a part of this specification are incorporated herein to provide a further understanding of the disclosure. Here, the drawings illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.
Referring to
Referring to
In another embodiment of the disclosure, the electronic apparatus 100 may also includes a display unit 140, which is configured to display a message in connection with the signal SA to remind the user. The display unit 140 may be a touch screen or a non-touch screen.
In one embodiment of the present disclosure, the speaker 130 has a driving device 132 and the diaphragm 134. The driving device 132 is configured to drive the diaphragm 134 to vibrate according to a signal outputted by the power amplifier 120 so as to generate an acoustical wave. In one embodiment of the disclosure, the driving device 132 is a coil, which is configured to drive the diaphragm 134 to vibrate in an electromagnetic induction manner. In addition, in one embodiment of the disclosure, the driving device 132 and the diaphragm 134 are respectively disposed on two substrates, and the driving device 132 is a thin film electrode formed by metal, and the diaphragm 134 may carry statistic electricity. The aforementioned two substrates may be made of fiber. In other words, the two substrates may be two pieces of paper.
In one embodiment of the disclosure, the time domain to frequency domain transform executed by the processing circuit 110 is a Fourier transform, and the Fourier transform includes a fast Fourier transform (FFT). In one embodiment of the disclosure, the time domain to frequency domain transform executed by the processing circuit 110 is a Laplace transform.
In addition, in one embodiment of the disclosure, the voltage value of the audio signal SIN is represented by a time function v(t), the current value of the current I is presented by a time function i(t), where t represents time, and the processing circuit 110 executes the time domain to frequency domain transform on [v(t)/i(t)] to obtain one frequency response curve. The processing circuit 110 executes the time domain to frequency domain transform on [v(t)/i(t)] to obtain the frequency response curve, and the feature value corresponding thereto is the impedance of the speaker 130. In one embodiment of the disclosure, the processing circuit 110 executes the time domain to frequency domain transform on
to obtain one frequency response curve, where Rdc is a resistor value of the driving device 132 of the speaker 130 under a room temperature (about 25° C.), and a constant value B1 varies with of different speakers 130. The processing circuit 110 executes the time domain to frequency domain transform on
to obtain the frequency response curve, and the feature value corresponding thereto is the stroke of the diaphragm 134.
In one embodiment of the disclosure, the electronic apparatus may further include an augmenter, which is configured to augment a source signal to generate the audio signal SIN. Referring to
Referring to
The processing circuit 110 determines whether the frequency response curve C3 falls within a predetermined area A. When the processing circuit 110 has determined that the frequency response curve falls within an area B rather than within the predetermined area A, the processing circuit 110 sends the signal SA to remind the user of the electronic apparatus 100. The aforementioned areas A and B are defined by an upper-limit curve BU, and a feature value corresponding to the upper-limit curve BU based on each frequency may be configured according to different user demands.
In light of the foregoing, the disclosure is directed to an electronic apparatus capable of self-testing whether a speaker thereof is operated normally. Since neither an anechoic room nor an acoustic analyzer requires to be additionally installed, the usage convenience may be significantly enhanced, and the testing cost for the speaker may be lower down.
Although the disclosure has been described with reference to the above embodiments, it will be apparent to one of the ordinary skill in the art that modifications to the described embodiment may be made without departing from the spirit of the disclosure. Accordingly, the scope of the disclosure will be defined by the attached claims not by the above detailed descriptions.
