Headphone Sensitivity & Efficiency Calculator

June 25, 2013

The calculator below converts headphone efficiency to sensitivity or vice versa for the specified headphones. Since headphone impedance Rphones varies with frequency and is complex, this calculation assumes a single real (resistive) nominal impedance value (usually at 1 kHz). The output of the amplifier is modelled as a simple series circuit with an ideal voltage source Vs in series with an internal resistance Rs. R1 and R2 are optional external series and shunt resistances. The calculator displays the output sound pressure level (dBSPL), the corresponding RMS headphones voltage and the headphones power dissipation. Default values for Vs and Rs are those for the Samsung Galaxy S4 SGH-I337 smartphone at full Music player volume. Default headphone values are for typical high-sensitivity earbuds:
Headphone Sensitivity / Efficiency Converter and dB SPL Calculator
  Rphones (ohms):      Sensitivity (dBSPL/1Vrms):     Efficiency (dBSPL/1mW) :   
  Vs(Vrms):    Rs(ohms):      R1 (ohms):      R2 (ohms):   
  dBSPL (Circuit):      Phones Voltage (Vrms):      Phones Power (mW):   

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