What does “open circuit sensitivity” mean?
The Open Circuit Sensitivity specification tells how much electrical output a microphone produces in response to certain sound pressure input. If two microphones are subject to the same sound pressure level and one puts out a stronger signal (higher voltage), that microphone is said to have higher sensitivity. However, keep in mind that a higher sensitivity rating does not necessarily make one microphone better than another microphone with a lower sensitivity rating. At Audio-Technica, we test Open Circuit Sensitivity by placing the microphone in a sound field with a frequency of 1 kHz at a sound pressure level of 1 Pascal (1 Pa, which is equivalent to 94 dB SPL); then we measure the voltage at the microphones output terminals. A note about decibels: In the audio world, a decibel (dB) is a mathematical shorthand that is used to represent how two different audio levels compare to each other. It is a logarithmic ratio (logarithms use powers of 10 to make large numbers smaller and easier
Open circuit sensitivity is the microphone’s electrical voltage output for a given sound pressure input. This is tested by putting a 1kHz frequency tone at a sound pressure level of 1Pascal or 94 dB into the input of the microphone capsule with the voltage output being recorded. The AE3000 cardioid condenser microphone has an Open Circuit Sensitivity of -43 dB (7.0 mV) re 1V at 1Pa. This means that a 1 kHz tone at a sound pressure level of 1 Pascal produces a voltage of 7.0 milivolts. The output voltage in decibels is referenced to 1 volt (dB re 1V) by using the following formula 20Log(0.007)= -43.098 dBV.
