This subwoofer has 25mm one way xmax (50.8 mm total), and with 475w rms from the amp, it fills the bottom end nicely. This is the kind of excursion you see on 15's.

It is low sensitivity at 87 db. In the sealed enclosure it starts to get good only at higher volume. It is an entry level SPL subwoofer and requires more amplifier wattage in sealed enclosure. Huge bass from a fairly small cone. My enclosure is .78 cu ft, recommended is 1.0- 1.35 cu ft. I know it would be deeper with more cubes, just don't have the room.

For the money, its a steal. The TNT manual drawings are incomplete. Its true cutout size is 9-1/8" and could be tapered from 9" even. Measure twice cut once! I wasn't about to ruin a 1" baffle, (that 9 5/8" cutout figure is bunk. that's the distance from bolt hole center-to-center).