Introduction: Mini Bluetooth Speaker Mega Bass

About: Diy and gadgets

Check the video above to see it playing

Homemade bluetooth speaker with nice bass:

Bluetooth Module:


Passive radiator:

Protection board:

DC module: or:

18650 Batteries: or:

18650 Holder: or:

Drill Bit used : or

I present you "The Mini Speaker" !

-Simple design, easy to build, painted with black mate spray can

-Tiny 40MM / 1.5 inch speakers and radiators

-Recorded with camera mic

-Protection board with balance function

Step 1: Case

I had pre-build the case, its 12 cm x 6 cm x 6cm, mark the place for the speaker holes.

Step 2: Speaker Holes

The speakers have 40mm wide so i made a slightly smaller hole.

Step 3: Back Cover

I cutted the back panel a little bit bigger, drill after the measurements for the screw holes, put it in place and sand it until it has no evident edges, this way its going to be the perfect size.

Step 4: Passive Radiators Holes

Repeat the process, in this case you can cut the exact diameter hole for the passive radiators because they will go inside the hole, a little bit of sanding may be necessary, but the ideal is to have a tight fit.

Step 5: Passive Radiators

Use flexible glue to secure them in place, glue around the radiators to have a perfect air seal when they are working.

Step 6: Gluing the Speakers

Put a small amount of glue at the edge of the speakers, put them in place and align them before the glue dries, when they are correctly aligned with the hole you can put more glue to assure an air tight seal, be carefull to not glue the rubber part of the speaker, glue only the metal part.

Step 7: Switches

Cut the holes for the switch and power jack, align and glue them, i did also a small "frame" to be able to secure the components better.

Step 8: Back Seal

Using the back panel as a template cut a piece of foam (about 1mm thick) to the same size of the panel, then cut the inside part of the foam to make room for the batteries, switch and power jack, glue the foam in place with flexible glue and we are ready for the next step.

Step 9: Batteries

Secure the two 18650 batterie holders using double sided tape, put the power jack and switch in place using flexible glue to alow a completely air tight seal when the case is closed.

Step 10: Light Indicator

Drill or cut a hole , i used a small screwdriver to do a small square in the middle of the case, them put a piece of clear plastic on the top of the blue led, that piece of plastic must fit also in the hole of the case to allow the blue light to be seen.

Secure the piece of plastic with instant glue (inside and outside) then trim the excess.

I painted the case with black spray paint, cover the speakers and radiators with masking tape while painting.

Step 11: Voltage Converter

- The maximum voltage from the batterie pack will be 8.4 volts, the amplifier module works with 5 volts, we need to reduce the voltage from 8.4 volts to 5 volts using a step down converter.

- Attach the speakers connections respecting the polarity of each one.

- Solder an micro usb positive and negative cable to the step down converter output, them add two more positive and negative cables for the input (they will be connected to the protection board).

Step 12: Battery Protection

-Solder the wires as shown in the schematic, i used an yellow wire to connect to the bms for the charging management.

-Solder also a positive and negative cable to conect the "+" and "-" from the bms input to the power jack, the positive red wire is also conected to the power switch.

-Solder the step down converter positive and negative cables to the protection board "B+" and "B-".

-Its a good idea to add shrink tube and hot glue to any cables to secure them and protect against vibrations .

-Put the back panel and turn the speaker on, while its on and using an x-acto and a small screwdriver i "scratched" the paint that was covering the plastic piece coming from the led light, its an easy thing to do because the paint will peel off easily from the plastic.

Step 13: Testing

It works !!! Check the video in the beginning of this instructable, its a furious little speaker ;)

Tank you for watching.

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