Wayne,
I think you have the T/S parameters for that driver, what does Pi alignment come up with, and what would the -3db be at. Down the road, I might want to downsize these cabinets and want to see how bottom end would be lost in a smaller cabinet.
Here is link to JBL 2242 driver specs if you don't have them:
http://www.jblpro.com/pages/pub/components/2242.pdf
Thanks, Ron