Anthony,
I'm in agreement with about 95% of your last post. No argument here. Most respectable 10" subs will have an F10 in the 20 hz range without any trouble and an F20 in the teens. with the transfer function (average 12 db per octave under about 60 hz or so) getting respectable levels of bass down to the low 20s is not out of the realm of possibility.
We could take this a step farther and say that no car can make a "real" 20hz signal because the wave could never mature because the car is not big enough.
Anyway, good post!
Dave
