Well sub is not playing right now but it sure does pass the knock test. THUMP! Instead of the ding!
I will add that after doing only half, the ding was still noticeably there. But once I finished with one layer, it was good to go! Of course who would go through with all that work to get the headliner down just to do half? //content.invisioncic.com/y282845/emoticons/crazy.gif.c13912c32de98515d3142759a824dae7.gif