The technical parameters of the Bluetooth headset are very important. Because the Bluetooth headsets we need are not only for listening to the phone, but more time for enjoying music, so when purchasing, we should pay attention to several important technical parameters such as impedance, sensitivity, frequency response and distortion of the headset.

Impedance: Abbreviation for the AC impedance of headphones. Headphones with different impedances are used in different occasions, and low-impedance headphones are easy to drive. Desktops or power amplifiers, VCD, DVD, TV, etc. generally use high-impedance headphones, while portable MD and MP3 players, mobile phones, etc. use general low-impedance headphones.

Sensitivity: That is, the sensitivity level. High sensitivity means that the power required to reach a certain sound pressure level is small, which is similar to impedance. The sensitivity of dynamic earphones is generally above 90dB/mW. If it is mainly selected for mobile phones or portable devices, the sensitivity should be above 100dB/mW.

Frequency Response The different values of the sensitivity in the Bluetooth headset PCBA at different frequencies are the frequency response. The human hearing range is 20Hz-20000Hz, and most people cannot hear sounds beyond this range. Expressing the dependence of sensitivity on frequency with a curve is called a frequency response curve. The frequency response unevenness given by general earphones is ±10dB, and the frequency response unevenness given by professional earphones and some high-end earphones is ±3dB, so the higher the frequency response, the better.

Distortion: Thanks to the low power of the Bluetooth headset pcba itself, the harmonic distortion of the headset is generally much smaller than that of the speaker. At the maximum rated power, the total harmonic distortion THD is less than or equal to 1%, which is basically indistinguishable by the human ear.