Where to find OEM Dali Epicon woofer?

Call Simply Stereo in Palatine, IL. Ask for Lee. Awesome guy, big DALI dealer.

Write to Dali tech support. https://www.dali-speakers.com/en-us/about-dali/technical-support/
They are a little slow to respond, but when I talked to them a couple years ago to discuss technical question Britta Olsen was pretty helpful. 

Hey John, check your private messages.  Just sent you some info that will hopefully help!