Hertz MPS 250 S4 subwoofer 10" (250 mm).

Hertz  MPS 250 S4 (MILLE series) subwoofer (250 mm).

Mille PRO shallow subwoofers have been designed to achieve exceptional performance even when there is very little space available to install the subwoofer box.
MPS 250 S4 is optimized to work in ultra-compact sealed boxesstarting from only 14 Lt (0.49 Cf). A typical example is a subwoofer enclosure under the rear benc of pickup trucks, where the space - and the height - are limited.
Mille PRO subwoofer have a depth/performance ratio never achieved before thanks to the impressive cone excursion capacity which is 20% higher than a traditional design
This exceptional target has been achieved thanks to the ingenious suspension group design featuring a dedicated support structure for spider and coil. 
This solution has allowed to move the magnetic group inwards, reducing the depth and at the same time maximizing cone linear excursion.