Neckbeard

It lowers the peak. But there are of course a lot of other variables are involved especially when in a vehicle. The best way is to just test different enclosures.

Nope doesn't matter one bit. Fs is just a function of the driver's moving mass and suspension stiffness. Which goes out the window once you have a box manipulating the back pressure (think of it like the stiffness of air suspension).

For reference: My subs have a Fs of 47. If I was limited to tuning above that, well.... Even for a burp box that's too high for some LOL

The Qtc of your enclosure starts from the Qts of your woofer. The Fs of the driver effects the Qts of your driver.

So depending on what type of alignment you are going for 0.5, .707, 1.0, or higher the Fs will effect it.

Higher the Qtc the higher the peak and steeper the roll-off to f3. Lower will create dampening with a slower roll-off to f3