From the published parameters I tried a simulation of this Fostex driver FE168EZ to know how they behave with and without the compensation network.
Freq Response (Orange), Impedance (Blue), Impedance Phase (Purple), SPL Phase ( yellow)
The above simulation without network indicate the SPL Phase (Yellow) intersects the Impedance Phase (Purple) at 0 deg phase which means the driver is designed excellently. But due to the self inductance of the voice coil the impedance phase rises and the load becomes more inductive. This could give rise to harshness and listening fatigue.
Adding an compensation network will have the below response -
As you can see the Impedance Phase (Green) now shows a resistive load with the effect of the rising phase with the voice coil inducatance been nullified. You can also notice that the freq response (Yellow) is now down by approx 2.2dB from the response without any network (orange) . Also the impedance (Red) is more flatter than without network (Blue). The most significant change is in the impedance phase (Green) than without the network (Purple).
As this is only from simulations, it will be interesting to note how this driver sounds subjectively with and without the network.
Freq Response (Orange), Impedance (Blue), Impedance Phase (Purple), SPL Phase ( yellow)
The above simulation without network indicate the SPL Phase (Yellow) intersects the Impedance Phase (Purple) at 0 deg phase which means the driver is designed excellently. But due to the self inductance of the voice coil the impedance phase rises and the load becomes more inductive. This could give rise to harshness and listening fatigue.
Adding an compensation network will have the below response -
As you can see the Impedance Phase (Green) now shows a resistive load with the effect of the rising phase with the voice coil inducatance been nullified. You can also notice that the freq response (Yellow) is now down by approx 2.2dB from the response without any network (orange) . Also the impedance (Red) is more flatter than without network (Blue). The most significant change is in the impedance phase (Green) than without the network (Purple).
As this is only from simulations, it will be interesting to note how this driver sounds subjectively with and without the network.
