These "Shallow-Mount" Subwoofers feature multiple patent-pending features to deliver the big bass performance of a full-size subwoofer, but in a compact design that can be installed either behind or under seats depending on the type of vehicle. The mounting depth is just 2-1/2" - less than half a typical subwoofer in this class.
One of the new patent-pending features is called the "Air Suspension Control System". This design locks in air between the main cone and drive cone, ensuring smoother and more precise movement of the cones, for superior linearity. The locked-in air behaves like a spring, so there's no need for a traditional spider structure. The drive cone also deflects air pressure inside the enclosure, which further contributes to the remarkable bass of the small package.