difrent cars will play dif fqs, ur subs box tuned and the shape of ur cars inside will play in that roll. best bet is to get a TL and play a sweep and that will give u an idea.
for my truck the peak tone is 36hz but the next guy with a jimmy/blazer may be 42hz
depends on the size of the box and there is just many things that will change the tuning of it but that can give you an estimate best way to find out is take the setup you got and just run it through a clinic or find someone with a tl