The Shiva-X is up on the web site. You can dig into the parameters on the PDF document. I'll get final production T/S parameters later next week.
These won't ship until early next week. Both the Shiva-X & Tempest-X are both in port clearing customs. I'm just trying to get a head start on web stuff and documentation.
http://www.diycable.com/main/product_info.php?cPath=24_93&products_id=653
Preliminary Box Designs:
Ported: 95L (3.35 cubic feet), fully stuffed, tuned to 18.4Hz looks good for a small enclosure. Use a full-length 4" Precision Sound Port to tune it.
120L (4.24 cubic feet), fully stuffed, with a full-length 4" Precision Port tunes it to about 18Hz. This is what I'd personally build for a ported alignment.
Sealed: For car audio you could easily do 40L (1.41 cubic feet), fully stuffed. Gives you f3 of 37Hz which actually would work really good in a car with all that cabin gain.
For home, I would aim for at least 60L (2.12 cubic feet) fully stuffed. A 85L cabinet (3 cubic feet) fully stuffed gets you a very nice Qtc = 0.707.
Power needed depends upon the box. All of these alignments will do fine with the 500W PE plate amp. That gets you pretty close to full output, clipping the amp right before the maximum output of the driver (a good thing). With the ported alignments I'd recommend a rumble filter.