There are exceptions to this, of course. For instance, the gentleman who wanted the sound from the subwoofer in the trunk of his limousine to reach the driver's cabin. This is a little much to ask (although I think he was able to come up with Something satisfactory anyway).

As you are saying this - I think you were speaking of me.
Well - I had this problem with a simple bassreflex-tube and a 12". I asked some people how to get a better sound - and finally after a visit in a car-hifi-studio I bought a new 12" (Dragster) and build a new (calculated) box. This time it was a bandbass box. I tried it out and it sounded much better. After thinking about it I redesigned the bandbassbox to a bit higher volume and to a special shape to take as less space from the trunk as it can get and to be as effective as possible.

NOW I don't have that problem that the sub doesn't reach the cabin any more. It's really powerful now. A sub is what you really need to make the sound round.

TeeMcBee