FYI they won't make a new line untill people stop buying the W7...
Most people who want SPL, and go to a JL retailer with moneys, will walk out with W7's none the wiser... Bigger sub would undercut the W7, and at around 1000 bucks a pop they can't afford that.
Assuming that they would make the bigger sub cheaper marketed as an SPL sub, The current JL strategy is that their subs = SQ + SPL
Also, alot of people who buy JL are buying something they didn't know they didn't want. (Ie: buying W7's for output) this usually works out great cause the W7's are pretty **** loud subs...
But make sub for pure SPL and watch the ignorant masses migrate away from JL cause that shit don't bump clean no more.
Also, JL audio manufactures everything on their own, a new line means new equiptment, expensive designing, etc. the only new products that you will see from a company so profit oriented as JL is obvious market advantages such as a powerful thin line sub, or increased efficiency amps to jump start dwindling amp sales.