The SB Audience woofer for the JTR 212 has been out of stock for a while on madi soundspeaker store, the link provided in the description of the build video. Luckily, I found a local business right here in Grand Rapids, Michigan that sells them and has them in stock. They are just a few miles away from where I live. Time to visit the store: https://meniscusaudio.com/product/sb-audience-nero-12mwn400d-12-mid-woofer/