Does anyone have the specs for the Fi BTL 15" subs. I am installing 2 of them for a customer, but he doesn't have any perameters for the subs. He is putting a Hifonics Brutus 2600 watt RMS d class amp on each sub. It is going to be in an old school s-10 2-door Blazer walled off right behind the front seats. Built for competition only, wanting to hit the biggest legal spl number at USAC competition. Any help would be appreciated. Thanks