麦克风的负DB详细解释

关于麦克风灵敏度的解释，x度一下，各种不靠谱，有的说DB越正越灵敏，有的说DB越负越灵敏，还是谷歌一下靠谱，见引文说法："In most modern audio equipment, microphone input impedance is substantially greater than that of the microphone itself. This input impedance is often 10 times the output impedance of the microphone, and thus may be regarded as an “open circuit.” Audio-Technica typically rates a microphone’s sensitivity using this open circuit output voltage, which is the output the microphone will deliver with a stated sound pressure level (SPL) input. This makes the open circuit voltage measurement very useful when comparing microphone sensitivity, maintaining a consistent standard, and achieving accurate sensitivity measurements. For the open circuit output voltage measurement, Audio-Technica uses a reference sound pressure of 1 Pa (Pascal), which is equal to 94 dB SPL. The microphone sensitivity is therefore stated in dB (decibels) as it compares to this reference level.

Because the reference level used is well above the output level of the microphone, the resulting sensitivity specification will be a negative number. The closer this number is to zero, the greater the signal provided to the input terminals. Thus, a microphone with a sensitivity rating of -40 dB is more sensitive than -55 dB, and -55 dB is more sensitive than -60 dB. "