Something funny going on because your first graph shows you're getting great response all the way down to below 2Hz, unless you have a rotary woofer, there is something funky going on. And with these graphs we cant see where the natural roll off of you sub is, and since you really don't want to boost below what your sub is capable of you need to find out whats going on with the readings.
BTW what sub do you have?
cheers
