I've been digging around in the forum for months - seeking to deepen my understanding of open baffle speakers & DSP most specifically. Hoping to be granted rights to email members soon so I can advance my education. Thanks!
Siegfried Linkwitz was known to dabble in dipoles:
https://www.linkwitzlab.com/design_of_loudspeakers.htm
https://www.linkwitzlab.com/design_of_loudspeakers.htm