For those of you who have built a Tempest:

Did you guys coutersink the driver? If so, how much? Is the cardboard-type stuff around the edge for internal mounting only? Can I rip it off if I mount externally, so I don't have to countersink as deep?

The Technical Data sheet for the Tempest from Adireaudio.com has a section called "Applications" in which it list performance for a sealed box size of 4 cubic feet (net) with 48 ounces of polyfill. Elsewhere on their site, in the Reference Designs page, the "Mid-Q" design is 4.6 cubic feet, but calls for only 32 ounces of polyfill. Of course, after factoring in the displacement of the driver and braces, it's probably around 4 cubic feet net too.
Why does the "Technical Data" example call for 50% more polyfill than the "Reference Design" example for the same size box?