My 300.watt amp and 2 kappa 6.5 turned up I can't hear my thunderheader

 

Must be the closed cap. Cuz mine are very loud. Had the old style mufflers with tunable disks on it when I bought it. But had cracked headers. So went with true duals and later model se supertrapp, non tunable, non rebuild able. Damn near the same sound, but smoother. My stereo now completely drowns out my pipes when cruising. Clear as day all thru the gears. Peace!