Chairman of the Bored
Join Date: May 2004
Location: St. Petersburg, FL
Bikes: 2004 Raleigh Talus, 2001 Motobecane Vent Noir (Custom build for heavy riders)
I say just get a sonic impact T-amp, gut the amp from it's housing...place it inside an altoids tin instead, and put all the connectors on the tin.
Buy some indoor/outdoor speakers...$10/pr
for KLH with a 4" woofer...3-way design. Use the mounting brackets to put them on your rear or front rack. Mount the amp nearby it. Use normal speaker cables to the left and right speakers. A standard patch cord to go from source to amp.
Now...for amp power...12v....12v scooter battery can be rack mounte as well....and provide over a week's worth of amplified goodness (these things get about 40 hours off of 8 AA batteries)
This is not only far louder than the computer speaker route, but also far more versatile....you can get a 12v wall-wart adapter and use this in your living room...T-amps put out more power than you would think.
It is a bit pricier though. I was thinking of doing this for quite a while as a joke, since I already have a T-amp gutted from it's case on my project bench.