It looks like you're new here. If you want to get involved, click one of these buttons!
I don't think many realized my InDIYana Tweeterectomy entry was a passive radiator bandpass using the acoustic filter to crossover to the fullranger.
I documented parts of the design, and the design approach in a git repo: https://github.com/Crumbs350/Loudspeaker_R2D2.
I might eventually get around to putting up VituixCAD or unibox profiles but figure the design logic given the odd entry is more useful.