At least as I have seen it practiced with my Merlins, the Zoebel has to do with presenting a more uniform load to the amp.
Wikipedia says that: "Some loudspeaker crossover designs include Zobel networks wired across the tweeter (high frequency) driver to compensate for the rise in impedance at high frequencies due to the inductance of the voice coil. The goal is to try to keep the load seen by the crossover circuitry as resistive as possible."
Based on my conversations with Pass, the specs for the Zoebel need to come from the amp manufacturer not the speaker manufacturer (ie the speaker doesn't know its there, the amp does)
There is no apparent downside - try them in and out and use it the way it sounds best to you.
Wikipedia says that: "Some loudspeaker crossover designs include Zobel networks wired across the tweeter (high frequency) driver to compensate for the rise in impedance at high frequencies due to the inductance of the voice coil. The goal is to try to keep the load seen by the crossover circuitry as resistive as possible."
Based on my conversations with Pass, the specs for the Zoebel need to come from the amp manufacturer not the speaker manufacturer (ie the speaker doesn't know its there, the amp does)
There is no apparent downside - try them in and out and use it the way it sounds best to you.