AudioCalcs
Preamp Gain Calculator — Required Gain from Mic Sensitivity
Calculate required preamp gain from microphone sensitivity and target recording level.
How We Calculate This
Mic Output Level
Mic Output (dBV) = Sensitivity + (SPL at mic − 94)
Microphone sensitivity is specified at 94 dB SPL (1 Pascal). For every dB above or below 94, the output changes by the same amount.
Required Gain
Gain (dB) = Target Level (dBV) − Mic Output (dBV)
Target level in dBV = (target dBFS + converter alignment) − 2.2
Frequently Asked Questions
Check the microphone specifications. Sensitivity is given in dBV (referenced to 1V at 94 dB SPL, or 1 Pa). Common values: large diaphragm condenser -32 to -38 dBV, small diaphragm condenser -35 to -40 dBV, dynamic mic -50 to -60 dBV, ribbon mic -50 to -60 dBV.
Dynamic microphones typically need 40-60 dB of gain for typical sources. Ribbon microphones may need 55-65 dB. Low-output dynamics like the SM7B recording quiet speech may need 60+ dB. This is why dedicated preamps or inline boosters (like Cloudlifter) are popular for these microphones.
Use the average SPL of your source at the microphone position. Typical values: quiet speech 60-65 dB, normal speech 70-75 dB, singing 80-95 dB, acoustic guitar 75-85 dB, drum kit 95-110 dB, guitar amplifier 95-115 dB.
All preamps add noise, characterised by their EIN (Equivalent Input Noise). At high gain settings, this noise becomes more audible relative to the signal. Better preamps have lower EIN (typically -125 to -130 dBu). For high-gain applications, choose a preamp with the lowest EIN possible.
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Last updated: February 2026
All calculations are estimates based on standard formulas. Always verify results for critical applications.