I want to calculate the Sound Pressure Level (SPLdB) of My PC headphones. My headphone specs says:
Maximum Power Input = 50 mWatt
Rated Power = 25 mWatt
Impedance = 32Ohm
Sensitiviy = 100dBSPL/mWatt
I used the formula
SPL(Pa) = Sensitivity * Power (A)
and
SPL(dB) = 20 Log (SPL(Pa)/(2 * 10^-5)) (B)
My questions are:
In formula (A) Which Power I have to use Maximum or rated?
The specs given at start are related to headphone only. PC soundcard output (say a fixed volume is selected at system volume control) does not play any role?
Are the given formulas correct? I have obtained them from googling.