Originally Posted by old_skool_noma
ultimately, with so many options for subs, i could get 8s that hit lower notes than some 18s with as many options as there are out any more, id just get what fit my application, or just to say that i had ___ number of ____ size subs, im putting 2 12s in my truck just purely for the sake of having 2 12s, i could just as easily have done 4 10s or 2 15s had i felt like spending the coin on them, i just didnt feel like finding some that were shallow enough
this is where its at.
There is no difference between sizes other than size. The differences come into play when the manufacturer skimps out a bit on the smaller models for less power handling or other things. granted, the t/s parameters change as well.
As far as the ability for a sub to keep up with rapid bass notes, or play certain frequencies... its all bunk when it comes to sizes. A 21 inch sub can and will play rapid bass notes just as well, and just as clean as ANY other size. Its a matter of dampening factor on the amp, and quality of the sub.
Go to a rock concert... look at the massive 20 foot tall tower of speakers and you will see HUGE woofers that have zero trouble playing these rapid notes.
Now, low frequencies are a bit different. As the frequencies drop, so does volume. Having more surface area helps out alot in the reproduction of low sounds, but again... a good quality sub shouldnt have an issue with it in a proper box.
So, "ultimately" the only difference is 2 inches when you disregard the physical differences between models that companies put in to save a buck.