3D Printed Speaker (DSP Tuned)

High-SPL Custom 3D Printed Speaker (DSP Tuned)

This is a custom-engineered, fully functional acoustic enclosure designed specifically for High-SPL (Sound Pressure Level) output and deep bass extension. With an internal net volume mathematically optimized at approximately 1000ml (1 Liter), this True Wireless Stereo (TWS) capable speaker punches far above its weight class, utilizing premium neodymium long-stroke drivers and a massive passive radiator.

🎥 Video Demos & Sound Tests

Hear the acoustic performance and watch the passive radiator excursion in action:

• Max Volume SPL Test

• 80% Volume Bass Test

📐 Acoustic Geometry & Structural Engineering

• Ribbed Bracing Matrix: Extreme internal acoustic pressure requires extreme rigidity. The internal chamber is reinforced with custom rib-like structures to combat panel resonance (wall-flexing) and prevent the plastic from absorbing acoustic energy.

• Acoustic Damping & Tuning: I have tested the enclosure both with and without polyester fiber fill. You can tune it based on your personal preference:

  • No Fill: The overall sound is very good, and the bass impact is extremely punchy and powerful.

  • Light Fill: Adding a very thin layer of poly-fill results in a cleaner, more clinical sound, though the bass attack softens slightly.

  • Pro-Tip for Mounting: To secure the poly-fill inside the chamber without using messy glues, cut small strips of the "hook" side of standard hook-and-loop (Velcro) tape. Stick these strips to the inner walls, and simply press a thin layer of polyester fiber directly onto the hooks. It holds perfectly and allows you to easily add or remove fill to tune the bass.

🔌 Bill of Materials (BOM) & Electronics

To replicate this exact acoustic profile, you will need the following components:

• Speaker Drivers: 2x GHXAMP 2.25-inch (55mm) Neodymium Full Range Drivers (4-Ohm, 11W). Featuring a carbon fiber cone and a large voice coil designed for extreme long-stroke excursion.

• Passive Radiator: 1x 135x75mm Passive Radiator. (Note: The original AliExpress link is no longer available. You can use any standard 135x75mm PR. If the weight differs, the system can be easily re-tuned via DSP).

• Primary Amplifier: DC5V/3.7V TWS Stereo Bluetooth 2*10W Board.

• Alternative Amplifier (Recommended for DSP): DC 5V TWS BT 10W+10W with Bass Enhancement & Type-C. This board is significantly better for precise DSP tuning, though using it will require some slight CAD editing to the 3D model's port cutouts.

• Battery: 2x HG2 18650 3000mAh 20A High-Discharge Cells.

• Power Management (BMS): 1x 1S 15A 3.7V Li-ion 6MOS BMS Protection Board.

• Sealing Tape: 1mm Thick x 5mm Wide EVA Foam Tape.

⚙ Print Settings & Assembly Instructions

Acoustic performance relies entirely on a 100% closed-box, airtight system.

• Walls & Infill (Crucial): To guarantee the rigidity required for high sound pressure, slice the main enclosure with a minimum of 5 wall loops (perimeters) and use Gyroid infill. This specific internal geometry provides multi-directional structural strength and prevents acoustic energy loss.

• Slicer Trick: Enable the "Ironing" feature for all top layers in your slicer. This creates a perfectly flat, glass-like mating surface for the gaskets, which drastically improves the hermetic seal of the acoustic chamber.

• Hardware & Fasteners: The model features captive slots for M3 nuts. It is highly recommended to use M3 Nylon Lock Nuts (Nyloc) to prevent loosening from extreme bass vibrations. If you only have standard M3 nuts, apply a small drop of B7000 glue to them. Mount everything using standard M3 screws and washers.

• Driver Mounting: The GHXAMP drivers have their own built-in rubber gaskets. Simply apply a very thin layer of dielectric/silicone grease directly to the rubber before screwing them down against the ironed plastic.

• Passive Radiator & Rear Cover: Apply the 1x5mm EVA foam tape to the mating perimeters. Smear a slight amount of grease on top of the tape, and screw it down against the ironed top layer of the enclosure.

• Internal Wiring & Rattle Prevention: High SPL means extreme internal vibrations. To prevent cables from rattling against the plastic walls and ruining the sound quality, wrap all internal wires in fuzzy fabric tape (automotive wiring tape). Secure these wrapped wire bundles directly to the front internal wall away from the passive radiator's airflow.

• Battery Bay: Wire the two 18650 cells in parallel to the BMS module. Secure the completed pack inside the dedicated battery bay using two zip ties.

• Amp Sealing (Advanced): The amplifier mounts to the exterior of the inner casing. Making this pass-through airtight requires delicate work. Apply hot glue or thick adhesive generously. Pro Tip: Temporarily tape the exterior buttons from the outside while applying glue from the inside—this makes achieving a perfect airtight seal much easier without ruining the tactile click.

• Acoustic Isolation Feet: I will be adding a dedicated TPU foot model to the project files in a future update. In the meantime, you must decouple the speaker from the surface to prevent mechanical rattling. You can easily do this by sticking standard anti-slip rubber furniture pads or thick foam mounting tape to the bottom of the enclosure.

🎛 DSP Tuning

To achieve a flat frequency response and push the maximum SPL without driver clipping, the audio pipeline must be digitally tuned. The DSP software is typically provided via a download link by the amplifier's AliExpress seller upon purchase. Using the software, you can implement custom EQ profiles, crossover adjustments, and dynamic bass processing based on whether you added polyester fill or swapped the passive radiator.

⚠ 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 batteries 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 high-discharge lithium batteries, please seek guidance before proceeding.