You know... you don't just put subs in ANY box.
I can't stand people that do that, then under power them only to end up with burnt voice coils in the end... In the very least if you do, and end up with hosed speakers. Blame yourself, and don't be the common idiot spreading X brand sucks...

Do you have the speaker's TS parameters? In the very least go with the recommended sealed volume.
It goes a long way extending their life... and (god forbid) will get you better sound.