I have drawn up a 218 version, but haven't built the prototype yet. Just goofing around at the moment with these things to test sealed designs. The '1822' prototype I have sounds really good to me. There are times when I love the sealed thing a lot. Super punchy and thick. I kinda figured at some point I may make them available, with and without mid drivers. Will most likely do a third prototype of the 1822 soon to test one more possible form factor. Would love to try a ported version as well just for kicks. I'm kinda over the moon for these 18" drivers I found
You still owe me lay out details.