Feeling the bass as well as hearing it is an important part of the equation. High end theaters use bass shakers for this very reason because the sensation of bass is just as important as hearing it. Sound traveling through air also loses energy much faster than it does traveling through a solid. I deal with that when we design buildings and donít want sound to travel through walls or floors. In those cases, decoupling the walls is more effective than adding mass or insulation to increase the STC ratings. I also renovated the Bose research and development building years ago and learned a lot. Those engineers do some amazing shit in that building. My crew was the first to construct a sound room for them that didnít rattle in years.

In car audio, the school of thought is ďwe donít want rattlesĒ and from an installers point of view I can understand this as you donít want customers coming back complaining about a rattle in the door or similar. For me, the trick is to couple the subwoofer to the structure of the vehicle AND deaden all the rattles that it might produce. The above mentioned securing the box down to prevent that the box from becoming a skull crushing projectile in an accident is also important and obviously when you do this youíve just coupled the box to the car. Build a fiberglass enclosure, even with foam between the car metal and sub box and guess what, youíve just coupled the box to the frame of the car. I think you guys do it all the time and may not even know you are coupling the box to the car. Itís a balancing act between rattles and feeling the bass. Going with huge cone area and thousands of watts is another way to feel the bass too but that costs much more.