The volts are different cause I'm calculating sensitivity at 1 Watt.
thats why it doesn't look right.---the system of equations
Watts = Current * Volts
Volts = Current * Resistance
---expanded solution
so Watts = Current^2 * Resistance
so Current^2 = Watts / Resistance
so Current = sqrt(Watts / Resistance)
since Volts = Current * Resistance
Volts = sqrt(Watts / Resistance) * Resistance
so Volts = sqrt(Watts * Resistance)
so 2.83V = sqrt(1W * 8) for 8 ohms.
2V = sqrt(1W * 4) for 4 ohms.
If you measure sensitivity at 2.82V/1M, then the Voltage will be the same and Wattage will be different.