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Microphones and Acoustics

Frequently Asked Questions

Get your most commonly asked acoustics questions answered.

Section I: Definitions and Terminology
Section II: Microphone Recommendations
Section III: Calibration and Testing
Section IV: Specification Clarifications
Section V: Specialty Microphone Applications
Section VI: Maintenance and Handling

If you don’t see the answer to your question, call our 24/7 SensorLineSM 716-684-0001 to speak with an application engineer or visit Ask the Acoustics Experts.

Will a preamplifier change the sensitivity of a microphone?

Yes, but the extent of the change depends on both the microphone and the preamplifier. All manufacturers will provide the gain (or attenuation when expressed as a negative value) usually in units of dB (re 1V/Pa). The attenuation is subtracted from (or the gain added to) the microphone sensitivity to give the nominal system sensitivity. For example, a microphone such as the 377B02 with a sensitivity of 50 mV/Pa or –26.02 dB (re 1 V/Pa) when used with a preamplifier such as the 426E01 with a nominal gain of –0.05 dB results in a nominal system sensitivity of–26.07 dB or 49.71  mV/Pa. For this case, the change in the sensitivity is only -0.6%. Some preamplifiers available on the market can have gains as great as -0.3 dB, which will drop the sensitivity by more than 3%. The best way to account for the preamplifier gain is to calibrate the sensitivity of a microphone with the preamplifier. PCB® offers both individual microphone cartridges as well as combined microphone and preamplifier systems.

Will a preamplifier change the sensitivity of a microphone?

Yes, but the extent of the change depends on both the microphone and the preamplifier. All manufacturers will provide the gain (or attenuation when expressed as a negative value) usually in units of dB (re 1V/Pa). The attenuation is subtracted from (or the gain added to) the microphone sensitivity to give the nominal system sensitivity. For example, a microphone such as the 377B02 with a sensitivity of 50 mV/Pa or –26.02 dB (re 1 V/Pa) when used with a preamplifier such as the 426E01 with a nominal gain of –0.05 dB results in a nominal system sensitivity of–26.07 dB or 49.71  mV/Pa. For this case, the change in the sensitivity is only -0.6%. Some preamplifiers available on the market can have gains as great as -0.3 dB, which will drop the sensitivity by more than 3%. The best way to account for the preamplifier gain is to calibrate the sensitivity of a microphone with the preamplifier. PCB® offers both individual microphone cartridges as well as combined microphone and preamplifier systems.