To be honest I dont think you even came close to a 140db score with that little power for starters. I still would like to know what kinda box and what kinda car. I would guess somthing more like a 125db. Not trying to down you, but being honest. I mean we got rangerman over here doing a 142db I think, with a outstanding woofer and amp. His amp probably does 4 times what yours did.......
i know it wasn't 140 db cuz first it was metered on the floor the box is 4 cu ft in a grand marquis, and plus not on link x mic, so i was just thrown out a test number, i know i can not hit a true 140 db with those subs
On the floor? The trunk floor? With a huge box like that im assuming it was ported? That would mean you need alot more power then what you had to even come close to a 140db.