i know for a hatchback u can gain around 16dBs. is that the same for an explorer if the sub is facing the hatch?? if not how many dBs do u gain?? (in a slot ported box)
You won't gain 16dB from a hatchback alone. that's an increase equal to about sixteen times the power of the current system. you might gain between 3dB to 6dB at most.
Anyway only real way to tell is to get the system metered.