u/EricLGN

Been working on a 3D printed stereo boombox called SignalForm. Here’s the component stack:

•	Dayton Audio DMA105-8 4” dual magnet aluminum cone full-range drivers (×2)  
•	Dayton Audio ND105-PR 4” passive radiators (×2) for bass extension  
•	Dayton Audio KABD-250 2×50W amp board with DSP and Bluetooth 5.0 aptX HD  
•	Dayton Audio LBB-5Sv2 5×18650 battery system running 21V  
•	Tactile volume, bass, and treble controls via KABD-SPF function cables  
•	12mm latching stainless power button  
•	Printed in PETG

The passive radiators and sealed enclosure design get surprisingly deep bass out of a 4” driver. Polyfill damping in each chamber. Epoxy and silicone sealed backplates — no air gaps. The KABD-250 DSP lets you tune the response curve to compensate for the enclosure size.

Ran a crowdfunding campaign. Didn’t fund. Released everything open source under CC BY 4.0 instead.

Full BOM, 3MF, STL, STEP files, and a complete assembly guide including wiring and first power on quirks are all on GitHub.

MakerWorld: https://makerworld.com/en/@ericbrunner
GitHub: github.com/PrintedPulse/signalform

Happy to answer questions about the acoustic design or component choices.

I designed a Bluetooth boombox called SignalForm. Dayton Audio components, dual 4” aluminum full-range drivers, passive radiators, 21V 18650 battery system. Bambu Lab featured it. I ran a crowdfunding campaign.

23 backers. Didn’t fund.

Sat on the files for months. Felt wrong. So I’m releasing everything under CC BY 4.0 — free to build, sell, or remix. Just put my name on it.

What’s included:

• 3MF, STL, and STEP files
• Full BOM with part numbers and sources (\~$160 in components)
• Complete step-by-step assembly guide
• GitHub repo for remixes and community builds

MakerWorld: https://makerworld.com/en/@ericbrunner
GitHub: github.com/PrintedPulse/signalform

If you build one I want to see it.

Designed and printed a two-tone retro CRT enclosure for an ESP32 air quality monitor. SH1106 OLED in a deep CRT tunnel bezel, knurled dial, asymmetrical rabbit ears, crown molding top, heat set inserts on the removable rear panel. PLA Tough+ with PETG support interfaces on the X2D.

The electronics work great. But honestly the enclosure is what I can’t stop looking at.

The shell is the real hero here. So before I drop the files on MakerWorld I want to know what the community would build with it. Retro game console display. Alarm clock. Scoreboard. Crypto ticker. Music visualizer. The form factor works for basically anything with a small screen and a knob.

So I’m releasing the shell as a standalone download. Same OLED window. Same encoder mount. Same rear panel system. Just the cabinet — you bring the project.

Clock. Ticker. Visualizer. Game. Whatever.

What would you build in this thing?