I just bought some of these from somewhere else (no offense Crutchfield) and I cut the holes in my box and put them in. I wanted to know how big a difference there was with them, so I took a piece of cardboard and covered the tube's hole with it. The speakers seemed like they made much less bass with the hole covered, and so I took the cardboard out. I tested it again, guess what? It sounds great now! I recommend these...