I picked up a 200W home audio powered sub yesterday at an auction for $20.
Brought it home and ran a couple of wires off the bottom cabinet speaker of the JP, through a line level converter and into the sub....
The effect is amazing
![Cheesy :D](http://www.aussiepinball.com.au/Smileys/classic/cheesy.gif)
We had it cranked and it makes the dinosaur growls and other effects awesome. My wife went crook upstairs and complained that the windows were rattling!
Great fun if you have a spare or cheap sub lying around.