with passive sub, would i be required to have an amp to drive that? or would the power from the HU be sufficient(i doubt). let's say i'm talking about a 10" sub.

with active sub, i guess i wouldn't need an amp for that, and can be directly connected to the HU. But if in the future, i install an amp, is it still okay to connect the active sub to an amp?

my main concern is that i don't have an amp yet(not in the next few months) to drive a passive sub. plus, an active sub is easier to remove and install in case i need the trunk space...i heard.