The APS 10 D is designed to deliver maximum performance in a sealed enclosure with ultra-compact volumes, from 10 lt. to 12 lt. The dual voice-coil and single voice coil versions feature push connectors for ease of wiring and configurations. Prima subwoofer components have been developed with a primary goal: to deliver high output in tight spaces. Output is a matter of excursion; the more air the cone moves, the more output. However, reduced mounting depth traditionally has meant low excursion. Prima subwoofers employ a special cone-dust cap-basket geometry which guarantees a large excursion of the mobile group while keeping the mounting depth to a minimum. The surround and spider have been carefully designed to prevent the “rocking-mode” phenomenon. The cooling circuit has been designed with air vents on the basket underneath the spider, eliminating the need for vents on the bottom plate. This allows the subwoofer to be mounted close to the back wall of the enclosure, making the most of the reduced mounting depth.