Slot Load Venting improves bass response. The wide, long Slot Load Vent dramatically lessens turbulence, noise and distortion, pouring out a tidal wave of precise, thunderous bass!. Polk subs sound better because they're built better. Rock-solid MDF construction (including a 1 inch thick front baffle) suppresses enclosure panel resonance for distortion-free, accurate response. Big 12 inch Long Throw Driver for longer excursion and better linearity. Huge Hi-Roll Surrounds that support their longer excursion.