Subwoofer school's in session. You've now enrolled into KICKER U, where you have instant access to a toolbox of mobile-audio installation knowledge. Let KICKER U help you design and build custom enclosures and assist with wiring subwoofers. This version contains calculators for figuring Port Dimensions and Tuning Frequencies and includes the ability to upload and save Thiele-Small parameters to create boxes for any driver you own. Network permissions are needed for Facebook and dealer locator.