Relationship Between Sensitivity and DB

I have a question -

A couple of people have told me that the higher the sensitivity rating on a sub, the louder it will get in real life. Is this true? I though a 15" Subwoofer w/ a sensitivity rating of 96.4 Db just required more power than a 12" w/ a rating of 93 Db? I've noticed that, in general, the bigger you go in sub size the large the sensitivy number gets, so maybe it does have something to do with loudness. An Audiobahn's ABB123Q Triple Angle 12" Sealed Bass Box has a sens. rating of 102 Db. Does this mean it would be significantly louder than there dual 12" (99 Db)? Maybe I'm reading into this spec too much.

Very nice site, but could someone explain just the sensitivity rating in layman's terms?

That's one of the many different things that I've heard before too.

BigJMan, I agree with tdsteele, the sensitivity is the relative to the amount of power required to move the sub.  The higher the figure the less power needed to move the sub. 

However, when comparing subs db only tells how efficient the sub is and this does not really equate into its' loudness.  Subs are designed to move air and the more air that is accurately moved the louder the sub will be.  I have heard a lot of stories about the Audiobahn's and they were all good stories..

But before you opt. for your subs listen to them at various levels with the type of music you enjoy listening to.  Some subs sound loud when you hear the music provided in the shops but are slopey when playing what you like..