If the speaker has a 4 ohm dip at the crossover frequency I would have no worries. In this case we have have two woofers in parallel to create the 4 ohm impedance- that is not a dip. So a set of ZEROs is recommended as this is not an eight ohm nominal speaker, it is more like a 4 ohm nominal speaker.
Now my comments are based on what I have been able to find on the web, and I did not find an impedance curve. If the woofer region of the speaker's impedance curve is indeed 8 ohms then the ZEROs will not be needed.
Now my comments are based on what I have been able to find on the web, and I did not find an impedance curve. If the woofer region of the speaker's impedance curve is indeed 8 ohms then the ZEROs will not be needed.