Hi Roland,Most of the Eminence 10's are tuned like this. They're really midrange/midbass drivers and great for horns or direct radiating mids. They have small Vas and low Qes so the boxes are tiny and bass response isn't very deep. Pialign recommends a 0.368ft3 chamber tuned to 86Hz, and BoxPlot reccomends half this size at about the same tuning, 0.19ft3 at 91Hz. The PiAlign'ed solution has f3 of about 95Hz and the BoxPlot tuning has f3 of about 120Hz. With a subwoofer, that's fine. But if used alone in a π cornerhorn configuration, I'd probably go with 1.0ft3 tuned to 35Hz. The use in corners will help the response a lot. Another alternative is the Alpha 10, which will allow you to tune the system for much deeper bass, albeit in slightly larger cabinets. The Delta 12LF is another possible canidate for you, provided you aren't opposed to using a little bit larger speaker.
Wayne