Check out the new technology explained here: http://www.stevemeadedesigns.com/board/topic/197747-smd-first-look-at-new-woofer-technology-update-unboxing-the-19-t3-picsvid-inside/
Check out all build pics here https://www.stevemeadedesigns.com/board/topic/201800-rockford-fosgate-power-t3-19-sub-8ft3-ported-box-build-30hz-acrylic-window-update-122715-page-7/<