Typtically, heavier material (Aluminum) will play lower frequency that lighter material (Carbon Fiber). However, the lighter material will (should) have quicker response time. Personally, my van is becoming a demo/show vehicle. IT WILL do better #'s at lower frequencies soon enough. Busy designing an enclosure for my DMX15s that "should" enable bass boxing @158+dB with only 9K watts. Will be awhile till done, but I will keep you all posted when I start the build.