For this build, I wanted a Ka-Boom Box with a special super power. That power is to be water (& beer) repellant for use at the pool, beach or an outrageous party. Several components were used to achieve this goal and I found that my price point stayed on mark. While I have not actually had to test this Boom Box's super abilities, I feel confident that it will perform flawlessly. It is not meant to be dunked in the pool or used as a floaty in the ocean, it is just built to have an extra purpose of use - to be waterproof!

Parts Needed: This is outlined in Step 1.

Tools Needed:

Phillips Head Screwdriver
Adjustable Wrench
Scissors
Sharp Knife
Wire Clipper
Drill with Drill Bit
Glue - I use E6000
Soldering Iron and Solder (optional)

Time Needed:

About 2 Hours

Skill Level Needed:

Medium - Power tools and sharp objects required.

Compendium:

Step 1: Finding Your Parts

Step 2: Preparing Your Suitcase

Step 3: Creating Your Battery Pack

Step 4: Attaching Your Electronics

Step 5: Additional Options

Step 6: Videos

Music For Your Boom Box:

Step 1: Finding Your Parts

Whenever I start a new project I hit the computer for research. I am usually in search of the least expensive items I can purchase and still be satisfied with the final outcome. I don't always purchase the cheapest items I find, sometimes they are too cheaply made. Below, I will go through my parts list and help you find the least expensive options.

Vintage Suitcase - This one is tough. Vintage suitcases are all the rage these days and thrift shops seem to have gotten a clue. The best bet for finding a great case would have to be yard sales or your Mom's garage. There is also the possibility that you may run across one in a rural area where the trend has not quite caught on. I do not suggest searching online for the perfect suitcase, I can be a huge time-suck. I have also used metal camera cases in the past. I was fortunate enough to score this great case for $5.95 (before tax). You will want a suitcase that is greater than 13 inches wide, as we will be working with 6 1/2 inch speakers.

eBay
Goodwill

Amplifiers - I believe I have found the most bang for my buck with the Lepai amplifiers. They are inexpensive, lightweight and have several input options and ports. I usually spend between $8 to $19 for my amps.

eBay
Amazon

3.5mm Auxiliary Cord- Just your basic male to male cord that connects your Boom Box to your iPod. You can also use a stereo RCA to 3.5mm.

eBay - Keep checking, you can get these for next to nothing.
Amazon - Not so cheap.

Marine Speakers - I use Pyle Hydra 120 watt speakers. They have a high, 90dB efficiency and 4 OHM impedance. I realize they out-power my amp choice, you just have to be sure to not turn the amp to maximum volume. They provide a nice sound and decent bass. Oh, and they're waterproof.

eBay
Amazon

12 Volt Battery Pack - For this build I used 8 AA batteries. In previous builds I used an RC battery which jacks the price up considerably. Check my earlier Ka-Boom Box for links and a description for this battery configuration.

eBay
Amazon

Plugs - Connecting to the amp's power supply requires a 2.1mm X 5.5mm male plug. These plugs are everywhere, just look around.

eBay

Nuts, Bolts and Washers- I buy these at my local Ace Hardware store but they can be purchased online, as well. Machine screws work the best, be sure they all fit before you purchase them. The depth of your case may vary from my example, so measure and buy accordingly.

Nuts - 4 @ 32 Thread count, #8
Bolts - 4 @ 3/4 inch
Washers - 4 to fit the bolt.

Speaker Wire - The speakers usually come with wire but I like to use a heavier gauge wire, like 12 gauge.

Bicycle Inner Tubes- Inner tubes can be procured from a number of places. If you are like me, you have Inner Tubes saved for projects like this. Your best resource is your backlog of tubes in the garage. Most bicycle shops would be more than happy to save them for you - just let them know what you are building.

Bike Shop Dumpster
Ask Your FaceBook Friends, haha.

Heat Shrink Tube - I use a heat shrink tube to add a final touch and clean design to my Boom Boxes. They can be purchased at a variety of shops and is not necessary for your final design, it just looks great. I used them on the end of the speaker screws and to give the speaker wire a really clean look.

Step 2: Preparing Your Suitcase

In this step we will drill all of the holes you will need to add your components. We will also line the case with a thin strip of re-purposed bicycle inner tube to give it an extra waterproofing element.

Inner Tube Strip - Grab an old inner tube from your last flat tire. If you don't have one, your local bike shop will surely have one to give you for free - just tell them what you are making and I know they will be psyched to give you one. The strip of tube goes inside the edge of the case and seals it when closed.

Measure or estimate the width of the the strip you will need.
Next, measure the lengths you will need up to each corner.
Using scissors or a sharp knife, cut out your pieces. Don't cut the exact length just yet, we need some room to play with.
Depending on your case, you will need to cut corner pieces. This is a bit more of a precise cut and may take a few cuts. Be sure to cut a full 90 degrees for your corner pieces.
Make sure your tube pieces fit snug but do not cover or exceed the flat part of your groove.
Glue the corner pieces into place.
Now glue your straight pieces in, starting at one corner. be sure to not stretch your tube piece, it needs to be relaxed.
Once you reach the second corner, cut your strip to match the corner piece and finish gluing.
Repeat for the additional 3 strips of inner tube and the corners.
Let the glue set up for a few minutes and then close your case to be sure you have a snug fit.

Speaker Holes - Brand new speakers will come with a template to cut your holes. It is important that you place your amp and speakers in your case to find the best arrangement. You don't want them to touch once the project is complete. You may also want to consider placing the speakers lower on the case so that it doesn't fall over when sitting upright and blaring your tunes. I generally place my speakers on the front of the suitcase as they tend to look better from the outside. There are quite a few way to place everything, so take your time with this step so that you will be satisfied with the end result. I prefer a symmetry to my cases, be sure to look at everything before you make your cuts.

Using the provided speaker hole template, draw your circles onto your case using a permanent marker and mark the spots where your screws go.
Drill your screw holes and drill a starting point for your speaker holes. Drill just inside of the hole being sure to not drill outside of it.
Now cut your circles with a Jig Saw or sharp blade depending on the material you are cutting. Take your time with your cuts, we want them exact.
Drill the holes for the provided screws.
Cut a slot for the speaker screw mounting pieces and slide them in.
Place your speakers into the new holes to be sure your cut is exact. Cut as needed.

Amplifier Holes - Place your amp in the case, being sure to leave room in the back for your speaker wires, battery plug and MP3 cord. Also make sure that your amp faces up so that you have easy access to the knobs when the project is finished. This allows you to adjust volume and base when you open the case.

Mark your holes with your marker.
Drill your 4 holes.
Push your 4 screws through the new holes, from the back.
Place the amp over the 4 screws.
Slip 1 washer onto each screw and now thread the nuts on tightly.

Battery Pack - I generally attach my battery pack off to the side of my amp. I want to have easy access for changing batteries and I also want to have it close to the back of the amp. It most often attaches to the bottom of the case just below the amp.

Step 3: Creating Your Battery Pack

Before I screw everything together, I like to test that everything works properly. The amp comes with a wall plug and the speakers come with speaker wire in most cases. Plug all your pieces together and make sure they work well.

Battery Pack - I use old wall plugs that are easy to find around the house (from lost or old electronics). There are a ton of them at the thrift shop and you can purchase them for cheap online. The part you need is a 2.1mm Male DC Jack.

eBay

This is one of the cheapest components in the project and you just might have one laying around.

Strip you wires of the plastic housing to expose about a half inch of wire.
Matching your positive to positive wires, wrap them together.
Do the same for your negative wires and solder (optional) them together.
Wrap each connection with electrical tape or shrink wrap.
Put your batteries in, plug into your amp and turn your amp on to test your power connection.

Step 4: Attaching Your Electronics

Now that everything is cut and tested, it's time to attach the electronics.

Amplifier - I like to screw the amp in first. You will need the screws, washers and nuts from the parts list. You left room to add all of the wires, so well put them in after we put all of the electronics into place.

Put all 4 screws with washers from the outside of the case.
Set your amp over the 4 screws and add 4 locking washers. The locking washers will keep your amp secure from all of the bass pounding in the future.
Thread the 4 nuts onto the screws and tighten well.

Speakers - Placement is important for speakers as you will want as little wire as possible. I usually place the speakers so that the wire connections face down towards the amp. I really prefer to keep them as clean looking as possible. You will most likely be the only person who looks inside your boom box, so it's your call.

Set your speakers into their respective holes being sure that your wire connections are where you want them.
Line up your holes.
Screw the speakers tight using the provided hardware.

Speaker Wire - Attaching speaker wire is relatively easy but why go down that road when you can make it difficult for yourself? As I noted earlier, I like to use a heavier gauge wire than what comes with the speaker pair. I also like to add a bit of solder and heat shrink tube to secure and give it a clean look.

Cut enough wire to connect your amp to your speakers and then add about 2 inches to your total length.
Using your wire clippers, expose about a half inch of wire on the 4 ends of your wire.
Attach the wire with the white line to the white connections on both your speaker and amp. Repeat for the solid wire to the red connections.

Battery Pack - As detailed in the previous step, attach your battery pack where you can access it easily.

Step 5: Additional Boom Box Options

There are further modifications that can be added after all of the steps to produce a working Boom Box.

Bluetooth adapter - These can be found for pretty cheap on eBay. I purchased one for $4.95 but was not satisfied with the response. It created feedback through my speakers, so I'll have to work this one out.
Shoulder Strap - You can always attach D-rings to the sides of your case to attach a shoulder strap. This is actually pretty handy.
Wall Plug - The Lepai amp comes with a wall plug that powers from a socket in your home. Drilling an additional hole near the amp will make your case less waterproof, but I believe you can add a rubber grommet to help seal the water out.
12 volt Sealed Lead Acid Battery - The batteries last so much longer than the battery options that I listed previously, they also weigh quite a bit more than the other options. I went for the lightest option possible.
RF (radio frequency) Adapter - I have not investigated this option yet. I do know other cruisers who have used these successfully. This will allow you to pick up a signal from another radios output. I plan to use this option and will be sure to update this post once I figure this out.
EL Wire (Electroluminescent Wire) - I modified my firstKa-Boom Box with Sound Reactive EL Wire. The results were stunning.
Stash Stuff - There is room left over in your case to stash extra items. I suggest that you do not put containers with liquid in them, that has the potential to produce bad effects.