impedance stabilization on subwoofers

Any recommended approaches to doing this? I'm wondering if there is a method as to smoothing out the impedance spike in the low end range of subwoofers. I've been reading about zobel filters, but it seems most sources indicate that they're more practically used to stabilize rising impedances due to high frequencies, and not typical or practical in subwoofer systems. Thoughts and ideas?

Why are you worried about it? The purpose of a zobel is to normalize the impedance peaks of the driver; do flatten the impedance curve, so a PASSIVE crossover isn't affected by the impedance peaks... Are you using a passive crossover on your subwoofer? Then there's no need to address the peak. It'll be just fine.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

The impedance spike at the low end of a subwoofer response curve?  You mean at fs?  No, a zobel will not help with that.  Indeed, nothing will as it is a characteristic caused by the mechanical structure of the motor system.  It actually is a good thing as it helps protect the woofer from being destroyed due to over power at fs.  You want to design your system to operate above fs or below it, and if you're using a ported system the purpose of the port is to add output replacing that lost by the woofer impedence spike at fs.Support the12volt.com

Yeah, I was referring to Fs. Are speaker drivers more sensitive at Fs though?.. (less power for the same output) Or is there really nothing to do for boosting the output at and a little below the Fs in a SEALED enclosure?

No a driver is not more sensitive at fs, it is in resonance and you do not want to try and push the driver at fs.  You can try using EQ like a Linkwitz Transform circuit to push output below fs, just be careful you do not overpower the woofer.  If your sealed enclosure is not giving you the output you wanted, however, the best solution is to use a vented system and a driver with a lower fs.Support the12volt.com