Decibels and sensitivity

The decibel expresses a logarithmic ratio. Power uses 10 log₁₀(P₂/P₁); sound pressure uses 20 log₁₀(p₂/p₁). Doubling power is about +3 dB, while doubling pressure is about +6 dB. These are different quantities.

Sensitivity needs stated conditions, such as dB at 2.83 V and 1 m. That voltage represents 1 W only into a resistive 8 Ω load. Results from different methods are not directly interchangeable.