Step 1: Materials
- pair of speakers (mine were 3" inches in diameter)
- Lepai 2020a+ amplifier
- Dremel w/ sanding and cutting bits
- stereo mini male to stereo mini male cord
I found the suitcase on Craigslist for about $20. It's an old British suitcase from around the 1920s era, made of vulcanized fiber (http://en.wikipedia.org/wiki/Vulcanized_fibre). The speakers I got at Goodwill at $15 a pair, but you probably wouldn't go wrong buying/finding a better pair. The Lepai amplifier I got from Amazon for around $25, but took a while to ship from China. Dremel I got for around $35 (actually a Black and Decker rotary tool) but if you have one you obviously won't need to buy one. Drill and screwdrivers I had, and the audio cable I got from Radioshack.
Step 2: Taking Apart the Speaker
The speaker was held in place by four more screws, and came out fairly easily. My speakers had some sort of tiny disc that I guess was supposed to be a tweeter, but seemed pretty much ineffectual (I ripped one off, can't really tell the difference). If the speakers you get have tweeters, then try not to disconnect them when you take the speaker out of its enclosure.
Step 3: Prepping the suitcase
The holes I cut using a plastic/soft metal cutting attachment for the Dremel. I used that to kind of trace where I was going to cut, then used a simple cutting disc. Luckily, the vulcanized fiber is fairly soft, so after cutting I could use the sander attachment to make it a little neater looking.
Once you unscrew the case of the little Lepai, you might notice the outline is quite irregular. This made for some trial and error for cutting out the holes for it. You want to cut enough that you're not forcing it in, but not too much that you have empty space, and you can still screw the screws of the faceplate in. I tried to trace the outline, but it took many tries of cutting, sanding, trying to fit it in, then sanding some more, trying to fit it in, et cetera. Just try and take it slow, no need to shove it in and possibly damage the components (I may actually have messed up one of the LED lights, but I can live without that).
After you've drilled the holes, simply screw everything in. I had to drill some holes for the screws, but I used a slightly smaller drill bit size than the screw, then used force when screwing the screws in, and the material was soft enough that the screws made their own threading.
Step 4: Final Steps
I also wrapped the audio cord around the handle of the suitcase, which actually makes for a nice place holding my iPod. (Since my iPod is also my camera, I can't really take a picture of it there) I also had some velcro adhesive stickers so that I could velcro the AC adapter onto the suitcase itself for better portability, but that's far from necessary.
Step 5: Adding the Battery
I bought a SLA (sealed lead acid) 12v battery at 7.2 amp Hours from Amazon. I think it should make the stereo go for several hours, but I haven't really done any extensive testing. If you need a primer to learn about batteries like I did, this is a good start: http://www.ashdale.co.uk/items/products/ups/batteryreplacement/batteryguide.pdf.pdf
Basically all I did to connect the battery to the stereo was buy a DC power plug from Radioshack and some alligator clips. Attach a red wire to the red alligator clip, and a black wire to the black alligator clip so you know your negative and positive. Definitely don't want to get those confused. Then attach the wires to the DC power plug (I had to use a multimeter against the AC adapter to make sure I got the positive and negative in the right places).
Step 6: Adding a Solar Panel
I bought a solar panel with a charge controller that is specifically designed to charge 12v batteries, so basically perfect for my needs.
It was around $30 when I bought it, which I guess is fair enough.
To connect the solar panel to the battery, I just connected the wires to the charge controller, and then using the supplied alligator clips, just clipped it onto the battery along with the other clips. It look a little bit of doing so both pairs were secure.
Then I wanted to mount the solar panel so I could move it around depending on where the sun was, and where I wanted the stereo pointed. So I bought a couple hinges from my local hardware store, and simply screwed them into the back of the suitcase, and screwed the solar panel onto the hinges. This was made super easy by the fact that the solar panel metal housing had available holes.
Step 7: Last, but not least, Bluetooth!
I haven't noticed any degradation in the sound quality at all, which I was pleasantly surprised by, and it's really cool being able to browse the Internet on my iPod and play music at the same time.
$22 on Amazon, but that includes a charger, USB cable for the charger, an RCA to Stereo mini cable, and a pair of crappy headphones.
The only downside is the receiver has its own battery, so it can go out while the rest of the stereo is running fine and you have to recharge it, but the battery life has been pretty good from what I've seen.