1, first of all, should buy genuine headphones in the formal business. The failure rate of headphones is not lower than that of ordinary audio equipment. Once it have a problem, it is difficult to repair, and the service of the merchant becomes important. Don’t trust the low-priced products and false propaganda on individual websites to avoid being fooled.
2. Select headphones according to your listening situation.
Headphones are divided into head-mounted, earbuds and hanging ears. Headphones have excellent performance and strong anti-ｄｒｏｐ ability, but they are large in size and inconvenient to carry. They are suitable for use in fixed positions such as home or office. Earphones plug the pronunciation directly into the ear hole and are small. It is easy to carry, sound quality is good, sound interaction is strong, but the low frequency loss is large; the earphones combine the advantages of head-mounted and earbuds, and the shape is fashionable, which is very popular among young people.
3. Select according to the earphone parameters.
Impedance - Headphones with different impedances are used in different situations. High-impedance headphones are commonly used on desktops or amplifiers, VCDs, DVDs, TVs, etc. For a variety of portable walkers, such as CDs, MDs, and MP3s, low-impedance headphones are typically used.
Frequency response range - refers to the width of the frequency band that the earphone can deliver. The frequency response range of the high-fidelity earphone in the International Electrotechnical Commission IEC581-10 standard is 50Hz~12500Hz.
Sensitivity - refers to the amount of input power required by the source in the same loudness. For portable devices such as Walkmans, the higher the sensitivity, the easier it is to drive the headphones.
Harmonic Distortion - The smaller the distortion, the better the sound quality.
Frequency Response: The sensitivity value corresponding to the frequency is the frequency response. The image is the frequency response curve. The range that human hearing can reach is about 20Hz-20000Hz. The mature earphone technology has reached this requirement. . The frequency response range refers to the width of the frequency band that the earphone can deliver. The excellent earphone frequency response width can reach 5Hz-40000Hz, while the human ear’s hearing range is only 20Hz-20000Hz. It is worth noting that the criteria for defining the frequency response width are different, for example, 1/2 or lower than the average output amplitude, which is obviously different.
The average manufacturer is to reduce the output amplitude by 1/2 to the standard measured frequency response width, which is to say -3dB, but because of the different test standards used, some products are measured at -10dB. This is actually equivalent to a standard measurement below 1/16 of the normal value. Therefore, the width of the frequency response is greatly widened. When purchasing, users should pay attention to the frequency response width of different brands of headphones may have different test standards.
Sensitivity: The sound pressure level that the earphone can emit when the input power of 1 mW is input to the earphone (the unit of sound pressure is decibel, the louder the sound pressure is, the higher the volume), so the higher the sensitivity, the smaller the impedance, the earphone The easier it is to sound, the easier it is to drive.
Usually, the sensitivity of the earphone is actually the sensitivity level of the earphone. When it is applied to the electric power of 1 mW on the earphone, the sound pressure level generated by the earphone coupled to the artificial ear (dummy head), the power of 1 mW is the frequency. The standard impedance of the headphones at 1000 Hz is calculated based on the basis.
The unit of sensitivity is dB/mW, and the other one that is not commonly used is dB/Vrms, which is the sound pressure level produced by the 1Vrms voltage applied to the headphones. High sensitivity means that the power required to reach a certain sound pressure level is small, and the sensitivity of the dynamic earphone is generally above 90dB/mW. If it is for the Walkman, the sensitivity is preferably around 100dB/mW or higher.