Dayton 8" 2.5 way project

[officeboy]

I bought 4 of these nice drivers that were on sale, And now I need something to put them in, I had originally planned on doing the Dayton 8 , But I already have some MTM speakers, and I'd love to have a shot at making a highish efficiency TMM 2.5 way physically time aligned speaker (something like the Auriga but with 1/4 the cost drivers). Of course this would be only my third speaker-building project, and my first to do any design on myself.
I would guess that I could steal some design from the Dayton 8 plan. Cut the box and port size in 1/2 for lower ported speaker, And a sealed box size of about 1/2 cu FT seems ok for the other 8”.
But how do I find out the angles for phase alignment, and even more importantly, how do I setup the crossovers, I would guess that I could steal part of the low/high crossover from the Dayton 8 plan, and I would just need to come up with something for the sealed part of the 2.5 way, but of course I’m probably way off base,.
Could someone set me straight? Either point me in the right direction, or smack me and turn me right back around.

[swirv]

Your lucky. The silkie is now the DOTD at PE.