Sphere TWS Speakers

This is an advanced, fully functional 3D-printed spherical acoustic enclosure designed for True Wireless Stereo (TWS) operation. The internal net volume is mathematically optimized at 600ml to maximize the driver's low-frequency extension, developed entirely from scratch utilizing CAD and AI-assisted research.

📐 Acoustic Geometry & Structural Engineering

• Pyramid Diffuser Matrix: To combat standing waves and internal resonance, the inner walls feature a custom-modeled pyramid matrix. This geometric acoustic treatment breaks up back-wave reflections, ensuring a clean frequency response without the "boxy" sound typical of standard plastic enclosures.

• Extreme Durability: The enclosure is engineered for maximum structural rigidity to prevent panel resonance (wall-flexing). When printed with optimized slicer settings, the empty enclosure can withstand the full dynamic weight of an adult jumping on it without any mechanical deformation.

 🔌 Bill of Materials (BOM) & Electronics

To replicate this build, you will need the following components:

1. Amplifier: [Type-C / AUX Bluetooth TWS Amplifier Board](https://pl.aliexpress.com/item/1005007564926026.html)

2. Speaker Driver (2-Inch, 4-Ohm, 5W): I originally used the Aiyima 2-Inch Full Range 4 Ohm 5W Mini Woofer, but it is currently out of stock. Alternative: You can use any standard 2-inch (approx. 50-52mm) full-range driver with 4-ohm impedance and a 5W power rating. Just ensure the mounting hole distances match standard 2-inch specifications.

3. Power Management: 1x 1S BMS (Battery Management System) Module for safe charge/discharge cycles.

4. Battery: 1x 18650 Lithium-ion Cell (Recommend high-quality cells like LG, Samsung, or Panasonic).

5. Wiring: 20 AWG or 22 AWG Soft Silicone Wire (Highly recommended for flexible and secure internal routing).

6. Hardware: M3 Screws (Note: Hex nuts are not required for this model, the screws thread directly into the designed plastic holes).

⚙ Print & Assembly Instructions

• Material: PLA+ (Sunlu PLA+ 2.0 Black is highly recommended for maximum structural rigidity and layer adhesion).

• Walls & Infill: Use a minimum of 4 to 5 wall loops (perimeters). Gyroid infill is highly recommended to provide multi-directional structural strength and prevent acoustic energy loss.

• Supports: Normal supports are required only for the external bottom curve of the sphere.

• Internal Wire Routing & Chamber Sealing: Route the cables through the internal hole connecting the main speaker acoustic chamber to the rear electronics chamber. Crucially, after passing the wires, you must completely seal this hole with silicone adhesive (or hot glue). Failing to do so will cause air leaks and destroy the low-frequency acoustic pressure.

• Hermetic Assembly: Acoustic performance relies on a closed-box system. Apply high-density sponge isolation tape (gasket) or a thin layer of dielectric grease on the mating surfaces between the sphere and the cap. Tighten the M3 screws evenly to guarantee a 100% airtight acoustic chamber.

⚠ Safety Warning

Please exercise extreme caution during the assembly process. Soldering requires proper ventilation and care. Pay special attention when handling, spot-welding, or soldering the 18650 lithium-ion battery and the BMS module. Short circuits or excessive heat applied to lithium cells can cause severe battery failure, thermal runaway, or fire hazards. If you are not experienced with lithium batteries, please seek guidance before proceeding.