Share 'Bike Stereo'

So, I've been tinkering around with the idea of adding a stereo to my chopper bike for bike rides. A fellow from chicago posted an instructable which seems pretty cool, but not as loud as I'd like. I really don't want to pull an additional 50 lbs of weight (my chopper is a stretch). Here is his link: http://www.instructables.com/id/Bike-Stereo Anyone else have ideas?