Ian
I see 3 sensitivity figures, you gave 81.21 db, and I see both 88 db and 84.23 db in the spec sheet, 88 db under specifications (sensitivity), and 84.23 db/w/m under parameters SPL.  I have no idea which one is correct, if any.  You would probably have to contact the marketing department to find out what some of the (higher) numbers mean.  At any rate, it looks like this is a very inefficient speaker that is going to want lots and lots of power.  The only possible advantage to a speaker like this (IMHO) is that you can put it in a really small box...That said, I'd go with the DB10.  Just scale it up enough so the spreaker fits.

Better yet, I'd sell that speaker (or return it), buy a 12" Series II (on sale now at Parts Express for $75) and build a DB12.

Here's what the math says for max SPL output:
600w 88db 27kx speaker max output = 88 + 10log600 = 116 db
(but 600w is not continuous RMS so 300w would be better => 113 db)

300w 84.23 db 27kx spkr max output = 84.23 + 10log300 = 109 db

300w 81.21 db 27kx spkr max output = 81.21 + 10log300 = 106 db

Compare the above to a 12" Series II:
275w 92db series II max output = 92 + 10log275 = 116.4 db

Your choice

Dan

If you intend to use this in the car only I would prolly try the Half-Wedge set up since you only have one. I am sure one of the other designs (DB10 / DB12) would do but are much more complicated builds. Besides if you don't like the wedge simple turn it over and port the enclosure. Either way you should be able to find a set up that will work with your sub. My $0.02.


HT-EXT