They definitely have serious output...our windshield was really moving, but like AJ and Chris said, it's at 50Hz. I would definitely say that these subs will rock in a consumer trunk car, but we've been having a real hard time getting them to play down at the 30 - 35Hz range, which is where we need to be for a shop demo vehicle.
I love the build quality of these...even before we mounted the first one, we had them in our display room and everyone was really pleased at the build quality of them!!
We had kept making the port longer and longer expecting the note to drop, but no matter how long we made it (38" final depth), it still did not have the gut wrenching bass at any frequency below 50Hz.
I wouldn't say I'm disappointed, I'm just baffled...and I know between AJ and I, we have over 40 years of box building experience.
I'll give Jeremy a call today and see what he thinks.