In audio equipment, the electrical-acoustic or acoustic-electric conversion capability of the device is called the sensitivity of the device. Regarding active speakers, sensitivity refers to the magnification of the internal amplifier and the sensitivity of the speaker combination. Small power sources such as a Walkman with a large magnification and a small audio output power are loud. Regarding passive speakers, sensitivity refers to the loudness of the sound produced at 1M when the speaker combination gives a 1000Hz signal of 1W to the speaker. Sometimes some audio systems are forced to lower their sensitivity for the sake of sound quality and stability of work.
The sensitivity of speakers may be the most misunderstood of various common indicators. For a long time, the amplitude-frequency response of speakers has often been reduced to a single value, which is sensitivity. This is the source of misunderstanding. Some people think that this value indicates the loudness of a certain signal when a certain speaker reproduces; others think that two speakers with the same sensitivity have the same time division loudness when reproducing the same signal. Both views have limitations. In fact, the sensitivity of the speaker only reflects the sound pressure level of the speaker when it is aimed at a specific bandwidth and spectral content signal. Bluetooth speakers are recommended. If two speakers with the same sensitivity index have different frequency responses, the output sound pressure level may be different when the same signal is replayed.