yes this is my first post in here.
i have now those woofer (12) 15s and i will ride those for (3) jbl 14001.
in electrical i think (3) bsb dc 120 battery. i did have my old system with (6) those woofer and ground zero 1.2500DXII and two optima yellow top battery and get wired 16+ and 16- 35mm² cable for amp. and did get term lab 150.4db for peak 41hz, but i sold old car and now new project.
clamshell is new kind on wall to me and that why i asked here.