First I must say that Ray's sub-caption is right on... "No Life". please don't take that as a slant on your person, you are of a very high intelect and that is duely noted. As to the question at hand, everything that incures some sort of movement will breakdown. The entire physics involved in reproducing a sound wave via a speaker will cause a movement that degrades the inital state of the compounds used in diaphragm. This will cause a curve of sorts somewhat shaped like the bell-curve with a much higher inital point than termination point. It will have some inital increase in flex (the break-in) how much increase will depend totally on the elements used, as well as the shape, width, arc, and so on. If you were to graph the amount of air movement to time you would recieve a resultant graph that is slanted slightly left. So unless you plan on replacing your speakers more often than the delta T of the graph to reach it's inital point from the peak, the "break-in" will be of little importance to you. This does not mean it does not exist, nor does it mean it does not increase the sound quality or life span of the material used in the speaker. Allowing the speaker become "flexable" at a constant rate will provide a longer lasting speaker. As to sound quality, you should reach the same or very near the quality of a broken in speaker with a speaker not broken in over some time.