Introduction: Hand Built Full Range Portable Bluetooth Speaker

About: student at SRM university , Btech mechatronics Loves finding out how things work and trying it myself . Loves anything that's a combination of electronics and mechanical .

Hii everyone , In this instructable I will be showing you guys how to make a powerful full range portable bluetooth speaker from scratch. The reason why I built this is I hate using earphones all the time and I dont like the isolation it provides. I always wanted a portable speaker system which I could take to get togethers and parties .It also serves as an awesome entertainment system for your worktable. The reason why I decided to hand build one is because building things is my hobby and the other thing is there was no way I was gonna convince my dad to buy me one ;-). Building It yourself also gives you the freedom to implement your own ideas,designs and modifications.

This portable speaker consist of 6 speakers , two 2 inch 3 watt woofers, two 2 inch 10 watt fullrange speakers and two 1 inch tweeters.The top panel is made up of clear acrylic sheet basically to make it look cooler.The Transparent panel allows you to see the vu meter LEDs and the internal wiring and circuitery. An other advantage is that you dont have to drill extra holes to see the lights on the charging modules and other circuits

The speaker system has dual passive radiators to give it that deep long bass .The audio receiver board used supports bluetooth , usb and SD so it widens connectivity.It has a 10000 mah battery so that you can enjoy hours and hours of music in a single charge.The box is hand built using 5mm plywood,multiwood and mdf which I found in the basement.

Step 1: SPECS:-

1. 3 watts per channel X 4 channels

2. 6 speakers including tweeters (full range)

3. 10000 mah battery (12 hours)

4. USB , Bluetooth, aux and SD support

5. Button feature

6. Micro usb charging

7. Dual passive radiators

8. VU meter

9. Transparent top panel

10. Designed for Wider hearing angle

Step 2: Sound Test

This is just a simple sound test which was shot using a smart phone, so the sound in the video might be a bit poorer than how it actually sounds , I didn't have access to any professional cameras so ended up using my phone camera.

Step 3: Things You Will Need:-

1. 2 inch Full range Speakers X 2

2. 2 inch mini woofers X 2

3. A pair of tweeters

4. Passive radiator pair 40mm X 70mm

5. 3.7 volt lithium polymer battery 5000 mah X 2 (18650 lithium ion batteries can also be used)

6. Battery charging module TP4056 X1

7. DC to DC step up module X 2

8. striped board

9. 1000 micro farad capacitor X 2

10. 4700 micro farad capacitor X 1

11. 5 volt amplifier PAM8403 X 2

12. 5 volt VU meter(optional)

13. Audio receiver board with bluetooth, usb and sd support

14. DC switches x 2

15. 5mm plywood sheet

16. 5mm clear acrylic sheet

17. 5mm multiwood sheet

18. 3mm female audio socket

19. Screws glue and other fittings

Step 4: Tools Needed:-

1. Screw driver

2. Soldering iron

3. Jig saw

4. sand paper

5. File

6. Drill ( hole cutting bits for the speaker holes, small disc cutting bit)

7. Hot glue gun

8. Scissors

9. Fevibond glue

Step 5: Making the Front Panel

1. The full range speakers and one of the passive radiators is aligned on the 5mm multiwood to get a rough dimension of the front panel.

2. The final dimensions which was measured as 19 X 6 cm is drawn on to the sheet using pencil and set squares

3. The rectangular piece is cut out using a jig saw.

4. The center of holes to be cut is found by intersecting diagonals.

5. Two 52mm holes and two 32mm holes are cut using the respective wood hole cutting bits.

6. The excess wood in between the 32mm holes is cut out using disc cutting bit .

7, The piece is filed and sanded to perfection.

Step 6: Making the Bottom Panel:-

1. Two parallel lines are drawn 8cm apart.

2. Mark two points 19 cm apart( length of front panel)

3. Two lines of 45 degrees are drawn from the two points towards the other parallel line.

4. The final shape is cut out using the jig saw.

Step 7: Making the Side Panels:-

1. A rectangular piece of 10.5 X 6 cm is cut out using the jig saw.

2. The midpoint is found out by intersecting diagonals.

3. 3" holes are cut out from the middle.

4. Both the sides of the panel is sanded to roughly 45 degrees.

Step 8: Attaching the Panels Together:-

1. The panels are first aligned then marked with a pencil the positions for screws.

2. Small holes are drilled at the marked positions 2.5 mm from the edges on the bottom panel.

3. Similarly , holes are drilled carefully on the side and front panels on the edges as shown in the pic.(These holes are drilled to prevent the thin plywood from cracking when the screws are tightened)

4. Glue like fevibond is applied on both the bonding sides and the panels are screwed into place.

Step 9: Making the Joints Airtight:-

Hot glue is used to make all the joints airtight.

Step 10: Attaching the Speakers and Passive Radiators:-

1. Glue is applied on both the bonding surfaces.

2. The passive radiator and the speakers are pressed into their corresponding holes.

3. The joints are made airtight using hot glue.

Step 11: THE CIRCUIT:-

Step 12: Making the Circuit:-

1. The output voltage from the DC stepup is set to about 5.3 volt by turning the potmeter.

2. A 1000 uf capacitor is soldered to the output terminals of the stepup.

3. The 3.7 volt batteries are connected in parellel.(18650 batteries can also be used connected in parallel)

4. The other modules and the battery are glued to the bottom panel.

5. The charging module is glued such that the female micro usb socket aligns with the bottom back edge as shown in the pic.( Use the new version of TP4056 which has discharge protection too)

6. The 4700 uf capacitor is soldered parallel to the battery.

7. All the connections are made as shown in the circuit diagram.

Step 13: Making the Back Panel:-

1. A piece of 5mm plywood is cut out according to the back dimensions, in my case it was 34 X 6 cm

2. The opening for the charging module is made carefully using a wood file.

3. The opening for the second passive radiator is drawn and cut out as explained in the front panel making step.

4. Both the shorter edges are filed from the inside until it fits perfectly with the side panels.

Step 14: Acrylic Top Panel:-

1. The acrylic sheet is cut using a jig saw according to the top dimensions

2. Holes for the audio receiver board case and the tweeters are cut at the right positions.

3. Holes for the switches are cut by first drawing the shape of the hole using a pencil and then drilling holes very close to each other along that line using the smallest drill bit.Then the tiny joints in between the holes are cut using a heated knife.The piece in the middle is taken out and the edges are made flat using a small triangular file.

4. The hole for the aux pin is drilled. The hole is kind of countersinked using a big wood bit because the latching bolt of the aux pin was not long enough to reach the other side of the 5 mm acrylic sheet.

5. The tweeter , switches and the aux pin is fixed to the panel and made airtight using hot glue.

Step 15: Attaching the Back Panel to the Base:-

1. Just like the front and side panels, the back panel is also attached by first drilling small aligned holes on the bottom and back panel , then its glued and screwed.

2. Before permanently attaching the back panel , Small blocks of wood with drilled holes is glued to it for finally attaching the acrylic top panel.

3. All the joints are made airtight using hot glue.

Step 16: Making Holes on the Acrylic Sheet for the Screws:-

1. The top panel is Kept in place.

2. The position of the holes to be drilled is marked.

3. The holes are drilled.

4. The drilled holes are countersinked using a bigger bit so that the screw heads wont protrude out.

Step 17: Adding Padding and Attaching the Acrylic Panel:-

1. Here I used a foam based double sided tape as the airtight padding.

2. The double sided tape is cut and applied on the edges as shown in the picture( without removing the nonadhesive layer which exposes the second sticky layer)

3. The connection to the tweeters and switches are soldered.The wires to the audio receiver board is pulled out through the opening in its case

4. The top transparent panel is finally screwed to the rest of the body after peeling off all the brown protective covering.

5. The excess foam tape from the sides is cut carefully and neatly using a razor blade.

Step 18: Connecting the Audio Receiver Board:-

1. A male micro usb pin is soldered to the power wires coming from the inside .

2. A 3mm male audio pin is soldered to the audio input wires coming from the inside.

3. Both the pins are inserted to the audio board and the setup is tested.

4. Once its working perfectly, the board is bolted into place inside its case and the case is closed using its own acrylic panel

5. All the holes are made airtight using hot glue.

Step 19: Smoothening the Edges and Adding the Bushes

1. All the corners and edges are sanded to perfection by hand using a sand paper or a sanding block

2. Rubber bushes are added to the bottom of the speaker as the speaker sounds better raised a few mm from the ground .It can be screwed on or glued to the bottom

Step 20: FINISHING and Additional Modifications:

Speaker grills can be added for additional protection of the speakers.Since the speakers are only 2 inches , 2 inch tweeter grills does a perfect job.

You can add cosmetic changes by painting , stickering or using vineers sheets to give it that finish and look you wanted .This step is optional ,if you guys are using vinerred plywood or mdf with the design you like , then no modifications is needed.

I have also added an other sound test video :)

And there you have it , a powerful 6 speaker full range portable speaker

If you guys have any doubts or queries , do post it in the comments below, I promise to reply to each and every comment

Thank you :-)

Audio Contest 2017

First Prize in the
Audio Contest 2017