deciBell ```dB = 10 log P for power dB = 20 log V for voltage Power ratio = 10^(dB/10) Voltage ratio = 10^(dB/20) power voltage 0.1 dB 1.02 1.01 0.2 dB 1.05 1.02 0.5 dB 1.12 1.05 1 dB 1.26 1.12 2 dB 1.54 1.26 3 dB 2.0 1.41 4 dB 2.51 1.58 6 dB 4.0 2.0 8 dB 6.31 2.51 10 dB 10 3.16 20 dB 100 10 30 dB 1000 31.6 40 dB 10k 100 50 dB 100k 316 60 dB 1M 1000 70 dB 10M 3160 80 dB 100M 10k etc. dB references Voltage dBu or dBv, reference is 0.775 VRMS dBV, reference is 1 volt RMS dBmV, reference is 1 mV across 75 ohms dBµV or dBuV, reference is 1µV Acoustic dB(SPL) (Sound Pressure Level), reference to 20 µPa dB = 10 log (Sound Pressure Level / 20 µPa) dB(PA), reference to 1 Pa dB = 10 log (Sound Pressure Level / 1 Pa) dB SIL (Sound Intensity Level), reference to 1^-12 W/m² dB = 10 log (Sound Intensity Level / ref) dB SWL (Sound Power Level) referenced to 1^-12 W dB = 10 log (Sound Power Level / ref) dB(A), dB(B), dB(C). these are dB SIL but with different frequency weighing filters. dB HL (Hearing Level) is used in audiograms as a measure of hearing loss Electrical Power dBm is db referenced to 1 mW dBW is db referenced to 1 watt they differ by a factor of 1000 or 30 dB dBFS (Full Scale) reference is the max signal the amplifier can handle dBTP (True peak) reference is the max peak signal the amplifier can handle ``` Home Area, Volume Atomic Mass Black Body Radiation Boolean Algebra Calculus Capacitor Center of Mass Carnot Cycle Charge Chemistry   Elements   Reactions Circuits Complex numbers Constants Curves, lines deciBell Density Electronics Elements Flow in fluids Fourier's Law Gases Gravitation Greek Alphabet Horizon Distance Interest Magnetics Math   Trig Math, complex Maxwell's Eq's Motion Newton's Laws Octal/Hex Codes Orbital Mechanics Particles Parts, Analog IC   Digital IC   Discrete Pendulum Planets Pressure Prime Numbers Questions Radiation Refraction Relativistic Motion Resistance, Resistivity Rotation Series SI (metric) prefixes Skin Effect Specific Heat Springs Stellar magnitude Thermal Thermal Conductivity Thermal Expansion Thermodynamics Trigonometry Units, Conversions Vectors Volume, Area Water Wave Motion Wire, Cu   Al   metric Young's Modulus