DIY Tough Bluetooth Boombox (Lasts 20hrs!)

Get ready to build a tough & rugged boombox! "RaveBOX (v1.0)" can charge USB devices, play MP3s and tune to FM stations! It also comes with an IR remote offering better convenience. The boombox gives action sports and outdoor enthusiasts 18 hours of nonstop music. Whether you're at the beach, shooting rapids, or hiking outdoors, the boombox remains safe in its tough (Pelican-like) weatherproof shell.

How I Came Up With The Design:
It's been a while since I last posted my last boombox tutorial, it was pretty much a success but as we all know technology advances annually. RaveBOX is now as powerful as my old boombox but it's half the size of the old one.

I really had no design when I made this project, I had a "go with the flow" sort of vibe. One day I went to the mall to buy my usual supplies then suddenly I came across this generic Pelican-like case. They were selling it for like P480 ($9.60), I still had some speaker lying around, so I thought it would be cool to fit my four unused fullrange speakers + my 4" HiFi woofer. With no hesitation, I bought the awesome looking case. As I went back home, I started searching for parts in my inventory. I still had some amp chips lying around. I found two extra 2x3 Amp Modules (form dx.com) and my beloved Bluetooth Player Module (from dx.com).

All that's left is my battery, I wanted to make sure that my boombox would last a day of non-stop playback without charging, so I though of a solution! My robots are using LiPo batteries since they had a high "size to power" ratio, meaning they have a high mAh rating for their extremely compact size. Since the competition is still scheduled for December, I borrowed some of my LiPo batteries and decided to put them in my new speaker project.

Specs/ Features:
- 2.1 Channel Audio System (6W + 6W + 20W)
- USB Charging Capabilities (6600mAh)
- 18hrs Max Playback (LiPo Bat)
- Bluetooth 3.0 Audio Connection
- 3.5 Stereo Auxiliary Connection
- Equipped w/ FM Radio Tuner
- IR Remote Control

WARNING! You'll need some basic soldering skills, a little knowledge of electronics, and some patience to build this. Please don't blame me if you mess up the modules. SMD chips are very sensitive to over-voltage, handle them with extreme care! There's a lot to go wrong with this project. Good luck!

Step 1: Tools & Materials

Audio Modules & MISC:
- Bluetooth/ FM/ USB/ SD Player Module (w/ Remote)
- 2-Channel 3W PAM8403 Audio Amplifier (2pcs)
- Generic Watertight Container (Pelican Knockoff)
- 3 Cell 2.2A Lithium Polymer Battery (Turningy)
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Speaker Alternatives:
- 3W Fullrange Speakers (4pcs) [Alternative#1]
- 3W Fullrange Speakers (4pcs) [Alternative#2]
- 4" Woofer Speaker (8 ohms) [Alternative#1]
- 4" Woofer Speaker (4 ohms) [Alternative#2]
- 4" Woofer Speaker (8 ohms) [Alternative#3]

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TDA2005 Amplifier Parts:

Capacitors (25V)	Resistors (¼w)	MISC.
220uF (2x)	120K	TDA2005 I.C.
100uF (2x)	2K	Screw Posts
2.2uF (2x)	1K	100kΩ Pot
100nF (3x)	12Ω (2x)	Heatsink
10uF (1x)	1Ω (2x)

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Tools, Materials & Equipment:
- Rotary Tool (Dremel)
- Leatherman Multitool
- Portable Electric Drill
- Silicone Applicator
- 40W Soldering Iron
- Mini Hot Glue Gun
- Electrical Tape

Step 2: Measuring & Marking

Get your vernier caliper/ ruler then transfer your speaker's measurements by using a compass & marker.

Step 3: Drilling & Cutting

Here's my secret! Many are having a hard time making perfectly round speaker holes with a rotary tool. If you've ever heard of the "sanding drum bit", now is the perfect time to buy one. Start of by drilling a large hole inside your circular markings then sand of the excess plastic all the way to your markings. The Leatherman is sharp enough to cut the plastic, you can use it for the switch's hole. 

Step 4: Clean the Edges

The rotary tool has left a jagged texture. Clear this off with your Leatherman's ultra-sharp blade then sand it of with a 300-grit sandpaper.

Step 5: Mounting the Speakers & Bluetooth Panel

1st.)  Drill four holes for the woofer's screw mounts.
2nd.) Seal the woofer's gap with a bottle of silicone sealant.
3rd.)  Use superglue to mount the four tiny full-ranged speakers.

Step 6: Wiring Instructions

Here's a detailed wiring diagram, it's easy and simple! :D

Notes:
- The Bluetooth module/ panel has an internal regulator (5-30v)
- Do not ground the speaker, they have separate lines
- They all share a common ground (negative wire)
- The PAM8403 amp module's "SW" pin is N/C
- Keep the wires as short a possible
- Observe proper speaker polarity! 
- Use thick wires for the mains

Step 7: Installing the Full-range Speaker's Amplifiers

Mount the PAM8403 amp module on both Left and Right speaker array. Refer to the image above for the wiring instruction.

Step 8: Finding a Good 5v Regulator

The PAM8403 needs a decent 5v regulator. The 7805 isn't enough to power two PAM8403 amp modules. Maybe it can, but by powering them with two separate 7805s. The 7805 is an outdated regulator, so better buy a 2 ampere USB car charger, it's much more effecient compared to having two 7805s. Plus the car charger's heat dissipation is much lower than the 7805s.

1st.)  Disasseble the cheap 12v USB charger
2nd.) Get the charger's circuit
3rd.)  Disolder the USB's female plug.
4th.)  Solder both PAM8403 amp module's 5v-input parallel to the 12v USB charger's 5v output.

Step 9: Mono Amp PCB Fabrication

Since last year, I started using photosynthesized PCBs (presynthesized). It's much more cleaner and faster compared to the toner ink transfer method. You can still do the toner transfer method. The PCB layout (PDF) is provided below.

Learn To Fabricate PCBs:Click Here (Visit My Other Tutorial)

Step 10: Assembling the Mono Amp

Follow the photo above for the part's layout. Solder them to their respective pins. 

Sorry! I forgot to flip my PCBs image, so I did the wrong side soldering method to get the pins right. Don't wory about the downloadable content, it's been corrected. If you are still confused, base the orientation on the schematic diagram.

Step 11: Combining L + R Channels for the Woofer

Since we have mono woofer, the woofer should share both left and right audio signals. 

The L-Channel, as shown in the diagram, goes to your Bluetooth module's left audio out. While the R-channel goes to the right. The M on the other hand goes to your woofer's amp (audio-input). 

Step 12: Choosing & Installing the Battery

I still had some LiPo batteries lying around in my workspace, I decided to use them for now. Lithium Polymer batteries serve as an excellent choice for long lasting power performance. The speaker can last for 18hrs @89dB, that's pretty good for an outstanding & punchy boombox. 

Remember, Lithium batteries don't like to get themselves drained for a long time, if they do, they bloat. And don't forget, they need special chargers, the ones with configurable LCD screens. Be careful with them and don't forget to do a monthly check on the battery!