It really depends on the drivers and the system design. Sometimes it helps the rolloff by damping the knee, even if it's not affecting the natural Le curve.
Generally speaking a Zobel's intended purpose is to flatten the impedance, which is not really an important feature if using a modern amp. If using a tube amp, you may want to flatten the impedance to keep a near 8 ohm impedance across the spectrum.
If it helps the response of your system, then by all means use a Zobel.
Comments
InDIYana Event Website
If it helps the response of your system, then by all means use a Zobel.