Do you know the knowledge of wireless bluetooth headphones？
Hedy
2021-05-14 10:16:16
1. The type of wireless bluetooth headphones
Wireless bluetooth headphones are classified according to their energy conversion methods, mainly including moving coil, electrostatic and isomagnetic. Separate from the structure, semi-open and closed. From the wearing form, there are earplug style, ear hanging style and headband style.
2. The difference between open and closed wireless bluetooth headphones
The shell of the open wireless bluetooth headphone is open, the open wireless bluetooth headphone is light in quality, the sound is natural, and there is no oppressive feeling. Because it is open, the sound leaks out, and the outside noise also enters. Semi-open wireless bluetooth headphones means that the wireless bluetooth headphone is open selectively, that is, it is only open to certain frequencies and closed to other frequencies, or it is open in a certain direction and closed in other directions. The shell of the closed wireless bluetooth headphone is closed to prevent outside sound from entering, and the sound leakage is reduced. It is used a lot in professional monitoring. The sound is generally very clear, rich in details, and low frequency response is very good. For most people, closed wireless bluetooth headphones have a sense of airtightness.
3. What is a high-fidelity wireless bluetooth headphones?
The main performance of the International Electrotechnical Commission IEC581-10 standard high-fidelity wireless bluetooth headphone is: the frequency response is not less than 50Hz to 12500Hz; the allowable error of the typical frequency response is ±3dB; the slope of the frequency response curve does not exceed 9dB per octave at 250Hz-800Hz The difference between the average sound pressure level of the left and right units in the same octave bandwidth is no more than 2dB. In the range of 100Hz-5000Hz, when the sound pressure level is 94dB, the harmonic distortion is no more than 1%, and when it is 100dB, no more than 3%; The frequency response is allowed to decrease between 2KHz-5KHz to improve transparency and sense of space.
4. What is the frequency response range of wireless bluetooth headphones ?
Frequency Response (Frequency Response): The sensitivity value corresponding to the frequency is the frequency response, and the graph is the frequency response curve. The range that human hearing can reach is about 20Hz-20000Hz. The current mature wireless bluetooth headphone technology has reached this Claim. The frequency response range refers to the width of the frequency band that the wireless bluetooth headphones can send. The frequency response width of an excellent wireless bluetooth headphones can reach 5Hz-40000Hz, while the hearing range of the human ear is only 20Hz-20000Hz. It is worth noting that the standards for defining the width of the frequency response are different, for example, it is less than 1/2 of the average output amplitude as the standard or less than 1/4 as the standard, which is obviously different. The general manufacturer measures the frequency response width with the output amplitude reduced by 1/2 as the standard, which means that the -3dB is the standard, but due to the different test standards used, some products are measured with -10dB. This is actually a standard measurement equal to 1/16 lower than the normal value. Therefore, the frequency response width is greatly expanded. When purchasing, users should note that the frequency response width of wireless bluetooth headphones of different brands may have different test standards.
5. What is the impedance of wireless bluetooth headphones?
Impedance: Pay attention to the difference between resistance and resistance. In the world of direct current (DC), the effect of objects on the current is called resistance, but in the field of alternating current (AC), in addition to resistance hindering current, capacitance and inductance It will also hinder the flow of current. This effect is called reactance, and what we call impedance is the sum of resistance and reactance in a vector. On desktop computers or power amplifiers, VCDs, DVD TVs and other machines with wireless bluetooth headphones jack output, it is generally appropriate to use medium and high impedance wireless bluetooth headphones. If you use low-impedance wireless bluetooth headphones, you must first turn down the volume before plugging in the wireless bluetooth headphones, and then turn the volume up a little bit to prevent the wireless bluetooth headphones from being overloaded and the wireless bluetooth headphones are burned out or the voice coil is deformed and misplaced, causing the sound to break. The impedance wireless bluetooth headphones are generally easier to push Therefore, portable and power-saving devices such as Walkman should choose low-impedance wireless bluetooth headphones. At the same time, attention should be paid to high sensitivity. Sensitivity index is more important for Walkman.
6. What is the harmonic distortion of wireless bluetooth headphones?
7. What is the sensitivity of wireless bluetooth headphones?
Wireless bluetooth headphones are classified according to their energy conversion methods, mainly including moving coil, electrostatic and isomagnetic. Separate from the structure, semi-open and closed. From the wearing form, there are earplug style, ear hanging style and headband style.
2. The difference between open and closed wireless bluetooth headphones
The shell of the open wireless bluetooth headphone is open, the open wireless bluetooth headphone is light in quality, the sound is natural, and there is no oppressive feeling. Because it is open, the sound leaks out, and the outside noise also enters. Semi-open wireless bluetooth headphones means that the wireless bluetooth headphone is open selectively, that is, it is only open to certain frequencies and closed to other frequencies, or it is open in a certain direction and closed in other directions. The shell of the closed wireless bluetooth headphone is closed to prevent outside sound from entering, and the sound leakage is reduced. It is used a lot in professional monitoring. The sound is generally very clear, rich in details, and low frequency response is very good. For most people, closed wireless bluetooth headphones have a sense of airtightness.
3. What is a high-fidelity wireless bluetooth headphones?
The main performance of the International Electrotechnical Commission IEC581-10 standard high-fidelity wireless bluetooth headphone is: the frequency response is not less than 50Hz to 12500Hz; the allowable error of the typical frequency response is ±3dB; the slope of the frequency response curve does not exceed 9dB per octave at 250Hz-800Hz The difference between the average sound pressure level of the left and right units in the same octave bandwidth is no more than 2dB. In the range of 100Hz-5000Hz, when the sound pressure level is 94dB, the harmonic distortion is no more than 1%, and when it is 100dB, no more than 3%; The frequency response is allowed to decrease between 2KHz-5KHz to improve transparency and sense of space.
4. What is the frequency response range of wireless bluetooth headphones ?
Frequency Response (Frequency Response): The sensitivity value corresponding to the frequency is the frequency response, and the graph is the frequency response curve. The range that human hearing can reach is about 20Hz-20000Hz. The current mature wireless bluetooth headphone technology has reached this Claim. The frequency response range refers to the width of the frequency band that the wireless bluetooth headphones can send. The frequency response width of an excellent wireless bluetooth headphones can reach 5Hz-40000Hz, while the hearing range of the human ear is only 20Hz-20000Hz. It is worth noting that the standards for defining the width of the frequency response are different, for example, it is less than 1/2 of the average output amplitude as the standard or less than 1/4 as the standard, which is obviously different. The general manufacturer measures the frequency response width with the output amplitude reduced by 1/2 as the standard, which means that the -3dB is the standard, but due to the different test standards used, some products are measured with -10dB. This is actually a standard measurement equal to 1/16 lower than the normal value. Therefore, the frequency response width is greatly expanded. When purchasing, users should note that the frequency response width of wireless bluetooth headphones of different brands may have different test standards.
5. What is the impedance of wireless bluetooth headphones?
Impedance: Pay attention to the difference between resistance and resistance. In the world of direct current (DC), the effect of objects on the current is called resistance, but in the field of alternating current (AC), in addition to resistance hindering current, capacitance and inductance It will also hinder the flow of current. This effect is called reactance, and what we call impedance is the sum of resistance and reactance in a vector. On desktop computers or power amplifiers, VCDs, DVD TVs and other machines with wireless bluetooth headphones jack output, it is generally appropriate to use medium and high impedance wireless bluetooth headphones. If you use low-impedance wireless bluetooth headphones, you must first turn down the volume before plugging in the wireless bluetooth headphones, and then turn the volume up a little bit to prevent the wireless bluetooth headphones from being overloaded and the wireless bluetooth headphones are burned out or the voice coil is deformed and misplaced, causing the sound to break. The impedance wireless bluetooth headphones are generally easier to push Therefore, portable and power-saving devices such as Walkman should choose low-impedance wireless bluetooth headphones. At the same time, attention should be paid to high sensitivity. Sensitivity index is more important for Walkman.
6. What is the harmonic distortion of wireless bluetooth headphones?
The output of the device cannot fully reproduce its input, resulting in distortion of the waveform or increase or decrease of signal components. Harmonic distortion is a kind of waveform distortion, which is marked in the wireless bluetooth headphones index. The smaller the distortion, the better the sound quality.
7. What is the sensitivity of wireless bluetooth headphones?
Sensitivity: The sound pressure level that the wireless bluetooth headphones can emit when the power of 1 milliwatt is input to the wireless bluetooth headphones (the unit of sound pressure is decibels, the greater the sound pressure, the greater the volume), so generally the higher the sensitivity, the lower the impedance, the wireless bluetooth headphones the easier it is to make a sound, the easier it is to drive. In layman's terms, the sensitivity of the wireless bluetooth headphones refers to the amount of power that needs to be input under the same conditions here. The higher the sensitivity, the smaller the input power required. For portable devices such as walkmans, sensitivity is an indicator worthy of attention.
