Introduction: Recycled Portable Bluetooth Speakers

Hi All,

I feel good about recycling and in this project, I recycled 3 items

  • Speakers : extracted from old desktop speaker
  • Lithium ion battery from old laptop
  • Wood from left over / discarded stack

Features

  • Bluetooth / AUX in/ FM/ TF card
  • Ultra thin ( just 50mm)
  • Volume control
  • Remote control
  • 6 to 9 hr battery backup
  • Weight Less than 500 gms
  • Recycles speakers total output : 6 W

Step 1: What Do We Need

Material

  • 2 Speakers ( 3 W each)
  • PAM8403 Amplifier with volume control ( 3w+3W)
  • MP3 / Bluetooth kit
  • 2 Li Ion Battery (18650)
  • TP4056 with Battery protection
  • 2 DC step up boost - MT3608
  • Wires
  • PlyWood
  • Switch - push button
  • Screws ( I extracted these from the original speakers
    • 8 screws to hold speakers
    • 8 screws to hold the back plate

Tools

  • Hammer
  • Fevicol / PVA glue
  • Black Spray paint
  • Soldering iron / wire
  • Hot gluegun
  • JigSaw with wood blade
  • Paper tape
  • Sand Paper ( 80, 150 and 220 Grit )

Step 2: Frame

To hold all the assembly, we will use 10mm plywood.

  • Cut a 2 pieces each of
    • 45mm X 180mm
    • 45mm X 100mm
  • Fix them at the edges at 90° as shown
  • Use fevicol or PVA glue
  • Use paper tape to hold all pieces in place
  • Let it dry for 4 hours
  • Using 80 grit sandpaper, make the edges smooth and straight

Step 3: Front Side

  • Cut a 180mm x 110mm plywood or MDF ( 4 mm thickness)
  • Make 45mm diameter holes for speakers, Note that my speakers were 50mm diameter
  • Cut appropriate holes for
    • Bluetooth / MP3 plate
    • Volume control ( PAM 8403)
    • Switch ( Not show in images, as I forgot and I added it while working on the electronic stuff )
  • Spray paint black ( glossy) as shown

Step 4: Back Side

  • Cut a 180mm x 110mm plywood or MDF ( 4 mm thickness)
  • Drill two hole for 16mm dia meter tube for bass as shown
  • Add required holes for TP4056 ( micro usb in)
  • and LED indicator ( I use a piece of stirrer for led indicator)

Step 5: Inside

  • Now to fix the speakers, we need to cut a mdf sheet (4mm thick) as shown
  • For battery fix two holder as show, we will hot glue battery on these, later
  • Let it fry for 4 hours

Step 6: Electronic

  • Follow the logical circuit diagram ( each single line represents both positive and negative wires)
  • TP4056 is connected to battery and two MT 3608
  • MT3608 is set at 5 V for PAM8403 and 9 V for Bluetooth Kit
  • Output from Bluetooth kit is connected to input of PAM8403
  • Two speakers are connected to PAM8403
  • Test the circuit before Assembly

Step 7: Putting All Together

Putting all together is difficult and take time, I fixed thing in following order

  • Power switch
  • PAM8403
  • Speakers
  • TP4056 and MT3608
  • Battery
  • Bluetooth kit

Pre-solder long wires to PAM8403, bluetooth kit and TP4056

Hot glue things in place

Step 8: Enjoy

After all the wiring is done, close the back panel. I used 8 screws to ensure no sound leakage.

Test it using different inputs like FM, USB etc

Improvement for furture

  • My speakers were 2w and output 3w, so disturbance at high volume
  • Current limited by TP4056 at high volumes, due to high current pulled by amplifier

Please share your comments, if you liked it