Ok, I thought I knew this one but I think I may actually be confused, here goes:
With everything else being equal, magnet size, power input, etc... is cone displacement the main factor in spl? Read on....
Being that spl is a measure of sound pressure, more air moved or pushed equals more pressure, correct? Now because for every action, there is an equal and opposite reaction, I know that more air pushed requires more power. But say we give an 18" sub the same power as we give the same series of 10" sub. The conclusion that I come to is that the bigger sub will always be capable of more spl due to it's displacement advantage, and ALL other things being equal. Now without everything being equal, comes another theory, more displacement must require more moving mass, which means efficiency to move air must be lost.
Now I know all subs are not created equal, and there are many many other variables involved, but is bigger displacement the general factor in acheiving higher spl? Or is less cone area better sometimes due to the fact higher spl's are generally produced in the 60-70hz areas and the moving mass of larger subs may hurt performance in these ranges? Basically what I'm asking is: Is it better to use more smaller subs, or fewer larger ones?