Wouldn't it be a nice challenge to design 3 way

David thank you, as a matter of fact I have 2 sheets of 15 mm BB left in my garage but I like 18 Sound only it'll be a big box and heavy with the 15 mm and expensive drivers. I do have an inklings towards a 1/2 mm BB which I can get at Woodcraft saves me a trip to my distributor 67 miles away. I also like the Eminence 3012LF as I am using it now on a 3 way box and bulky, heavy, and no space in my suv.
I've been busy with the Thanksgiving weekend, I will start a drawing but not sure how to calculate internal volume specific to 3012LF ported to F3 at 60 Hz as I will be using my about to be finished JBL 215 loaded with 2226H as sub. Also I was thinking maybe a 5" mid don't know a good mid woofer for the money and put out good spl I also have a thick plastic 1" horn (6"x6"). I am assuming the 12" separated from the other components for better bass.
Can someone check if a 1.5 cu.ft. box will do on a ported 60Hz with the Emmy. As I have the same neo 12 in another cabinet bigger I am guessing 3 cu.ft. plenty of bass but not lower than 50Hz and now the driver is well broken in after over a dozen gigs since last year Jan 2020 when I finished the project. Any thoughts?