It seriously almost made me jump, and I'm pretty jaded when it comes to low and loud. Thunderbirds were in town this past weekend for an air show, and last week they were running drills over town. One of them went supersonic (illegally) over town, and right over our office building. I was in a meeting at the time and I was the only person in the room that didn't jump when it hit. I grew up within distance of Whiteman AFB, and in the 70's, walls quaking to sonic booms happened daily.
But this snuck up on me and startled me. I've ran boatloads of super-low material through this sub, but nothing has gone that tactile before. I've some organ material that puts a slight rumble into things, but this flat-out woke my wife up because the couch was literally quaking.
I love this sub. It's a total giggle factory.