I currently have a PB13/Ultra, and it does of good job of shaking the house. I thought about adding another sub, but when I turn my sub up to make the chairs shake, the bass is almost overwhelming. I thought about adding a second sub and tuning them both lower to get more shake without as high of spl, but then I got to thinking about bass shakers. Would this allow me to have that bass shaking effect without having to overwhelm the room with bass. This is way cheaper than adding a second sub so I was just wondering what everyone's experience with them was. They look like the would do a good job.