i took my old subs out of my truck and am puting one 10" 4 ohm dvc 400 watt RMS , It is already wired in the box, i used a DMM set at 200 ohms put it across the terminals on the box, reads 0.25 , my amp is a 2 ch at 250 RMS X2 @ 2 ohm , how do i wire it all up ,? i believe i need to bridge the amp right ?