Yeah, but what really matters is volume displaced, not necessarily cone area, which I'm sure is much higher with the extra Xmax. Do you have those figures yet?
On something like an average 12" surround you are looking at a geometric max of 27-35mm (31mm is a safe average) or so without damage compared to 58mm on our 12" surround (the 55mm figure is a more linear figure, but 58mm is geometric max).
So lets say 31mm x 1.0 (just a reference number) = 31 mm^3 of displacement x 2 = 62
Then 58mm x 0.9 (90% of SD) = 52.2 mm^3 of displacement x 2 = 104.4
Around 1.8 dB additional output when using the most of both. Even dropping to a more reasonable usage of, say, 40mm of travel...
40mm x 0.9 = 36 x 2 = 72 = 0.4 dB of additional output.
Doesn't take much to get a gain even with a bit of drop in SD //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
With all that being said -- theory only takes us so far and we've seen larger gains in output compared to theory in initial testing -- We have already made a "Hi-X" version of the Z v.3 12" model and have seen 1 dB gains on the meter vs stock models... a wider than average surround is used on them as well with an SD drop from stock cones -- and they don't gain nearly the throw.
Theory doesn't hold up as you also have the non-linearity of the surround coming into play as well as the spider... and we mate these big surrounds with much large, more linear spiders than the small surrounds -- so it's not all apples to apples in the whole driver package //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif