When you design a crossover from a formula and apply it in a situation similar to the one above, the results are less than spectacular. The component values were determined using 8 ohms for impedance and 200 Hz for the crossover frequency. This frequency was chosen so it would be close enough to the resonance of the driver that the crossover would be affected by it. The black curve is the response you would obtain if you used the components specified by the crossover design formulas without impedance correction. The third graphic shows how much closer to the desired response you will get by correcting the impedance of the driver.
R is the value for the resistor.
Calculate Your Series Notch Filter Here To use this calculator, enter the values of Fs, Qes, Qms, and Re for your speaker. It can however, be used on woofers, but the component values required are large and would be very expensive.