Dual Voice Coils and Unique Heat Management for a Thin but Powerful Sub ^^ Compact Enclosures with Tough MDF Construction for Behind or Under the Seat ^^ CompRT Features Forced-Air Cooling - 20% Cooler for Increased Reliability ^^ Active Thin-Mount CompRT Subwoofer Paired with Passive ReFLEX Radiator for Deep Bass ^^ Passive ReFLEX Technology Helps Create Loud Bass in a Small Box