DIY Surround Sound Bluetooth Speaker

Hey everyone! Want a badass, one-of-a-kind Bluetooth speaker? You've come to the right place!

This wireless speaker features Bluetooth 5.1 technology, a sick SP-107 RGB music processor, and some serious bass. The unique design offers 180-degree sound! You're probably wondering why that's cool.

Here's why:

1. Bluetooth 5.1 lets you stream music at higher bitrates for crystal-clear sound.
2. Four 3-inch woofers and a powerful TPA3116 amp deliver thumping bass.
3. The SP-107 RGB music processor creates awesome light shows to match your tunes.
4. 180-degree sound means your party will be rocking.

The speaker's enclosure is crafted from 12mm moisture-resistant MDF, while the front and top panels are constructed from double-layered 6mm MDF. MDF is an ideal material for acoustic speakers due to its exceptional vibration damping properties and ease of workability. The application of self-adhesive PVC film for the finish eliminates the need for toxic paints and results in a visually appealing aesthetic.

Specifications:

1. Supply Voltage: 4S(14,8V);
2. Max output Power (Amp TPA3116):
3. THD+N = 1%:   2 x 25W;
4. THD+N = 10%: 2 x 30W;
5. Frequency response:   80Hz-20kHz;
6. Wireless:   Bluetooth 5.1 (Qualcomm QCC5125);
7. Supports SBC/AAC/APTX/APTXLL/APTXHD/AD/LDAC;
8. Woofers 3 Inch, passive radiators 3 Inch, tweeters 2 Inch;
9. Enclosure's Dimensions: H=115mm; L=535mm; D=120mm;

I outsourced the fabrication of all MDF components to a furniture workshop, providing them with my detailed drawings. I performed the remaining assembly steps at my workstation. Let's begin!

Supplies

PARTS LIST:

Electronic components:

1. Poweramp board TPA3116 Bluetooth 5.1 Qualcomm QCC5125- https://fas.st/OS3joH
2. AIYIMA 4Pcs 2 InchTweeter Speaker 6 Ohm 30W - https://ali.ski/EDMpd
3. AIYIMA 4Pcs 3 Inch woofer Speakers 8 Ohm 25W - https://ali.ski/cQSBS
4. AIYIMA Speakers 2 Way Crossover - https://ali.ski/QGz1UC

Power supply:

1. 2X 18650 Battery Holder - https://ali.ski/tMPEUT
2. Bms 4s 18650 Li-ion Battery Protection Circuit Board - https://ali.ski/Dl1QI
3. XL4015 5A DC to DC Lithium Battery Step down Charging Board - https://ali.ski/g--3o
4. 4 x 18650 3000mAh Lithium-ion batteries;
5. DC4-100V LED Digital Voltmeter - https://ali.ski/iesGc

For lighting effects:

1. WS2812B LED Light Bluetooth/Music Controller SP107E - https://ali.ski/3xJCZ-
2. WS2812B Pixel Smart RGB LED Strip 144Leds DC5V- https://ali.ski/0hgR6
3. LM2596 DC-DC adjustable step-down power Supply MINI560 5V - https://fas.st/LiDmIa
4. Translucent Black Plastic Sheet 3mm - https://fas.st/go16u

Buttons and connectors:

1. DC Power Jack Socket 5.5*2.5 - https://fas.st/H55jl
2. 6mm Metal LED Indicator 12V Red Blue White - https://ali.ski/VEn83
3. 12mm Metal Button High Head With Light Switch Momentary - https://fas.st/BQGDEM
4. 22mm Waterproof Metal Push Button Switch LED Latching - https://fas.st/Ss6J-

External design elements:

1. Stainless steel double curved handle 80mm(8mm(201) M4) - https://ali.ski/DCBtu
2. AIYIMA 4Pcs Speaker Spikes Stand Feets - https://ali.ski/0jiEcg
3. Electric Guitar Pickguard Bracket Support Metal(Corners) - https://fas.st/pEddBn
4. High-grade Leather Handle Knobs Pull Furniture Cabinet 160mm - https://fas.st/t46cp

Fasteners:

1. M4x10mm Stainless Steel Hex Socket Head Self Tapping Screw - https://fas.st/b5U3pY
2. M4x20mm carbon steel wood screws black - https://fas.st/qSqJt
3. M3x12mm Stainless Steel Self-tapping Hexagon Screw(for speakers) - https://ali.ski/K1AoIw

TOOLS:

1. Drill Stand BG6117, - https://ali.ski/6Yb-D
2. XCAN Forstner Drill Bit 15-35mm Carbide Tipped Drill Bit Set - https://ali.ski/2_C3V
3. Hole Saws Kit 19mm-127mm - https://ali.ski/lSbhb
4. Digital T12 Mini Soldering Iron DC 12-24V 72W - https://ali.ski/swJsb
5. Welding Wire 1.5MM 63/37 FLUX 2.0% 45FT - https://ali.ski/BfAf3d
6. Drill Bit For Wood set - https://fas.st/ZHmBvI
7. Jig Saw Blade Set T-shank -https://fas.st/YNpnT

Step 1: Marking MDF Panels

MDF panels are easy to mark. For the most accurate results, I recommend using a 0.5mm mechanical pencil. For marking hole centers, I use a thin awl. The drawings can be downloaded here:

Step 2: Front Panel

Here's a breakdown of the front panel creation process:

1. Start with two 6mm MDF panels. These are the base materials for the front panel.
2. Create the cutout:
3. On one of the 6mm MDF panels, use a jigsaw to carefully cut out a rectangular opening measuring 105mm by 32mm.
4. Important: Before cutting, drill small pilot holes (6-8mm diameter) at each corner of the intended cutout. These holes prevent the MDF from splintering as the jigsaw blade enters the material.
5. Bond the panels:
6. Apply a generous layer of waterproof PVA adhesive to the surface of the panel without the cutout.
7. Align the two panels carefully, ensuring they are flush.
8. Place the assembled panels into a press.
9. Pressing:
10. Apply pressure to the panels within the press for at least six hours. This allows the PVA adhesive to cure completely, creating a strong and durable bond.
11. Result:
12. After pressing, you have a 12mm thick front panel with a precisely cut rectangular opening.

This process ensures the creation of a sturdy and well-constructed front panel that is ready for further assembly or finishing.

https://youtu.be/g0ahNpwzElI?t=24

Step 3: Drilling Holes

Drilling holes is a crucial part of constructing a Bluetooth speaker. Safety is paramount!

1. Initiate the process by drilling 2mm pilot holes.
2. Subsequently, drill holes for the drivers using hole saws: 72mm for the passive radiators, 75mm for the 3-inch woofers. Employ a flat blade feather bit for the 37mm tweeter holes.
3. For the control button holes, utilize a larger Forstner bit to drill halfway through the MDF from the rear, then finish with a standard wood bit to accommodate the button's diameter. This configuration facilitates convenient tightening of the button's mounting nuts.
4. Drilling holes for the handles and screws as per the blueprint is uncomplicated.

Additionally, you'll need to use a rasp to create recesses (5mm x 30mm) for the woofer connectors.

https://youtu.be/g0ahNpwzElI?t=182

Step 4: RGB Strip Installation Area

I am adhering 2.5 x 2.5 mm wooden spacers to install a protective glass over the RGB indicator. Caution should be exercised when handling instant adhesive.

https://youtu.be/g0ahNpwzElI?t=229

Step 5: Gluing the Bluetooth Speaker Cabinet

For a quick and easy join, I use an electric staple gun with 1.2mm x 20mm nails to fasten MDF panels after applying wood glue. This method is a time-saver without compromising on the final result.

Screws or clamps can also be used.

Once the glue is dry (after at least 6 hours), you can glue on the central partition and reinforcing ribs.

https://youtu.be/g0ahNpwzElI?t=277

Step 6: Back Panel Support Blocks

Gluing 10mm square wooden blocks to mount the back panel.

Precision is key!

https://youtu.be/g0ahNpwzElI?t=343

Step 7: Final Finishing

Finishing the Bluetooth Speaker Enclosure:

1. Surface Preparation:
2. Sanding: Smooth out any imperfections using an orbital sander with 80-grit sandpaper.
3. Cleaning: Thoroughly vacuum the surface to remove dust.
4. Priming:
5. Apply a coat of PVA primer and allow to dry for at least 6 hours.
6. Final Sanding:
7. Sand the primed surface using 180-grit sandpaper.
8. Applying the Wrap:
9. Apply self-adhesive PVC film, trimming the edges for a neat fit.
10. Cutting Holes: Cut holes in the film as needed using a utility knife.
11. Mounting:
12. Feet: Install damping feet using screws.
13. Handle: Attach a stylish handle.
14. Finishing Touches:
15. Removing Bubbles: Use a hair dryer set to no more than 100 degrees Celsius to remove any air bubbles from the film surface.

https://youtu.be/g0ahNpwzElI?t=408

Step 8: Controls and Indicators

The top panel of the Bluetooth speaker features three control buttons for Bluetooth 5.1, a power button, and a Bluetooth status LED indicator.

Installing Control Buttons involves the following steps:

1. Wire Preparation: Preparing wires, installing connectors and terminals.
2. Button Attachment: Soldering or connecting wires to buttons, pre-inserting mounting nuts.
3. Button Fixation: Securing buttons in place using nuts

https://youtu.be/g0ahNpwzElI?t=681

Step 9: 2-Way Crossover Mounting

The 2-way crossover boards are attached to the speaker enclosure using 2mm thick double-sided adhesive tape. The tape is heat-resistant.

https://youtu.be/g0ahNpwzElI?t=834

Step 10: RGB Music Processor SP-107

RGB music visualization is built using WS2812B addressable RGB LED strips and an SP-107 RGB music processor. The following steps are involved:

1. Cut the required number of LEDs from the LED strip. In our case, two strips of 14 LEDs each.
2. Solder the end of one strip to the beginning of the other, following the indicators on the strip.
3. Solder the connecting wires. 4. A DC-DC step-down converter is used to power the system with +5 volts.
4. Connect all boards according to the diagram and mount them in the enclosure using 2mm thick double-sided heat-resistant adhesive tape.
5. Before mounting the RGB strip, paint the installation area black.

https://youtu.be/g0ahNpwzElI?t=864

Step 11: Speaker and Protective Handle Installation

1. The woofers and tweeters have an impedance of 8 ohms and 6 ohms respectively, and are connected in parallel pairs. The speakers are equipped with connectors of different widths to prevent polarity reversal.
2. They are mounted using M3x10mm screws.
3. The hex recessed head of the screws prevents the screwdriver from slipping and damaging the speakers.

A unique feature of this Bluetooth speaker design is that the hole for attaching the protective handle on the top panel coincides with the vertical Back Panel Support Block. Therefore, a hole for a countersunk screw is made in the Support Block. After installing the protective handle, the vertical Back Panel Support Block is glued into place.

1. Mounting the passive radiators is straightforward.

https://youtu.be/g0ahNpwzElI?t=1018

Step 12: Speaker Enclosure Sealing

1. To ensure optimal performance of the Bluetooth speaker, all technological openings must be sealed with silicone sealant.
2. For enclosure sealing, 2.5mm thick self-adhesive damping foam tape is installed on the Back Panel Support Blocks.

https://youtu.be/g0ahNpwzElI?t=1187

Step 13: Power Supply Construction

All power modules are mounted on the rear MDF panel.

18650 battery holders are secured with 2x8mm screws.

The following components are installed:

1. DC Power Jack Socket 5.5*2.5;
2. LED battery charge indicator;
3. LED voltmeter with a button for battery voltage control;
4. Additional sealing is provided with silicone sealant;
5. The XL4015 battery charger module and BMS 4s are mounted on 2mm double-sided thermal tape.
6. Connecting wires are soldered according to the diagram and fixed with hot glue.

https://youtu.be/g0ahNpwzElI?t=1230

Step 14: Bluetooth 5.1 Power Amplifier Module

The power amplifier is based on the Texas Instruments TPA3116D2 chip.

TPA3116D2 features:

1. Supply voltage: 4.5 V to 26 V;
2. Total harmonic distortion + noise: 0.1%;
3. Signal-to-noise ratio: 102dB;
4. Frequency range: 20 Hz to 22 kHz;
5. Output power vs supply voltage is shown in the graph.

The Bluetooth 5.1 module is based on the Qualcomm QCC5125 chip and supports SBC/AAC/APTX/APTXLL/APTXHD/AD/LDAC codecs.

A line-level output for the SP-107 music RGB processor needs to be added to the amplifier board. A line-level jack will be glued on and 0.22 uF non-polarized capacitors soldered to it for DC blocking.

Also, button connectors and a Bluetooth status LED need to be soldered onto the board.

The amplifier board is mounted to the rear panel with 2mm high-temp double-sided tape.

https://youtu.be/g0ahNpwzElI?t=1473

A schematic is attached:

Step 15: Filling Wire Channels With Hot Glue

The wire channels on the rear panel should be filled with hot glue and pressed down with a flat object to level the surface.

https://youtu.be/g0ahNpwzElI?t=1549

Step 16: Setting Up the Charger Module

1. Adjust the output voltage of the module to 16.8 volts at 1.5 amps using a multimeter and a screwdriver.
2. Insert the 18650 batteries into the holders, ensuring correct polarity.

https://youtu.be/g0ahNpwzElI?t=1679

Step 17: Internal Damping

Enclosure damping is a process aimed at reducing unwanted resonances within the speaker cabinet.

Fill part of the cabinet volume with foam.

https://youtu.be/g0ahNpwzElI?t=1715

Step 18: Important Final Details

1. Connect the connectors for buttons and power.
2. Connect the power and speaker wires to the amplifier board, observing polarity.
3. Use silicone to secure all connectors and 0.22µF capacitors to the amplifier board to prevent vibration damage.

https://youtu.be/g0ahNpwzElI?t=1587

Step 19: Final Enclosure Assembly

Install the back panel into the enclosure:

1. Attach with M4x20mm black carbon steel wood screws.
2. Attach the protective corners to the enclosure with M4x10mm screws.
3. Apply a 3mm thick translucent black plastic sheet to the RGB LED indicator using double-sided tape for protection.

https://youtu.be/g0ahNpwzElI?t=1728

Step 20: Final Check

1. Press the battery voltage control button.
2. If necessary, connect an external power source to charge the battery.
3. (I using a laptop power supply rated at 18V 6A.)
4.  Wait for the charging LED to turn off.
5.  Press the battery voltage control button again.
6.  A voltage of approximately 16.8 volts indicates a full charge.

You're all set!

https://youtu.be/g0ahNpwzElI?t=1806

Step 21: User Manual

Keys Description:

1. "P/V-": Short press the previous song, long press to decrease the volume
2. "N/V+": Short press the next song, long press and continue to increase the volume
3. "PLY": Short press to play/pause

Special function description:

1. "PLY": Press and hold for 3 seconds to force into pairing mode, press and hold for 6 seconds to clear the pairing list

You'll need to download an app to your phone to control the cool light shows on the SP-107E music RGB processor:

LED Chord:

https://play.google.com/store/search?q=led+chord+sp107e&c=apps&hl=en_US (for Android).

https://apps.apple.com/us/app/led-chord/id1427110872 (for iOS).

I'm really proud of how this project turned out. What do you think of my Surround Sound Bluetooth Speaker? Your feedback will help me improve. Can't wait to show you what I'm working on next. Oh, and don't forget to check out my YouTube channel!