I built a boombox to take to college and other adventures. I read as many instructables and /r/diy posts as possible and used SketchUp to create a design I liked.

Basic power tool and electrical wiring knowledge necessary. Not necessarily before, but definitely after :^)

Full parts list:

Lepai 2020A+ Amplifier
2x Rockford Fosgate 6.5" 3-way speakers
2x 2.5" recycled Bose sounddock speakers
UPG 8Ah SLA battery
Battery Tender Junior 12V charger
LCD Voltmeter
Dual row terminal block
4x Rubber feet
Port tube
LED rocker switch
3.5mm aux cord
7" handle
MDF (Medium-density fiberboard)
Jigsaw
Solder or quick connectors with wires
(I used the wires from an old power supply)

*Link to my website *Link to /r/diy thread

Step 1: Design and Construct

I provided the sketchup file for my design.

A friend and I used a table saw (though could be done with just a jigsaw) to cut up the main panels of MDF. I then used a jigsaw to cut out holes for the speakers, amp, and voltmeter. Add some stain+polyurethane and you're on your way.

Glue the panels together and install the speakers and feet.

Wireless Boombox.skp
Download

Step 2: Wiring

Both sets of speakers were 4ohms so I wired them in series to the Lepai amp since it can handle 2-8ohms.

Cut the power cord from the amp to the adapter and split the inner wires to yellow and black. Black being ground. The paint diagram shows cleanly how the terminal block works. I cut off the yellow and black wires from an old computer psu and crimped quick connectors to the wires for connection.

Test it out!

The battery charges while playing and will float charge once it reaches maximum capacity. The voltmeter can be read to determine the battery's charge. 12.00v ~ 25% This setup easily lasted me 3 days camping with friends. It surprised me how long it lasted, ranging from low to maximum volume. Also it charges quite quickly.

Step 3: Sealing the Box

Add a handle before you seal it if it is a handle that screws from the inside.

Seal up any areas which sound may escape with caulk and add some insulation for a cleaner bass. Glue on the final panel. Add a few screws on top and the sides for additional strength.

Add a grill to protect those speakers and tada you can hear this thing from anywhere in the house, across the lake, across the baseball field.... and anywhere else it will be taken next.

Step 4: Admire your work.

Feel free to ask me any questions!