Replacement woofer source for Entec Subwoofer?

I am looking for any sources for a replacement woofer for the Entec LF-X subwoofer. Entec, sadly, has gone out of business. The higher models of subwoofer use a 3-loop servo (position, veloicity and acceleration) and I suspect they use custom drivers. I saw an entry in the speaker forum about wiring a repaired driver but I couldn't contact the person who posted it. I would be very grateful for any ideas.