Project Resonator | The Open-Source IEM.

A love letter to the IEM/CIEM hobby.

🔧 Technologies Used & Software Required

1. VituixCAD — Tuning simulation (see install guide below)
2. KiCad — Schematic and PCB design
3. Autodesk Fusion — Designing the IEM shell
4. FPGraphTracer — Tracking frequency and impedance responses from driver spec sheets

Youtube Playlist For Addional IEM Building Resources

📅 Development Timeline

• Moved crossover simulation to the latest VituixCAD (old version archived under /legacy) | Crossover

• Updated driver setup to CI22955 + BK23824 + 2× SWFK 31736 | Drivers

• Removed PCB requirement in favor of direct SMD soldering (PCB file kept for reference) | Assembly

• Removed outdated SMD components list (will add new sourcing guide soon) | Documentation

• First physical prototype in progress thanks to preliminary funding | Prototyping

• [+] Modular, Node-based Tuning Software | Software

• Tools & Software | Wiki Entry

• Driver Selection | Wiki Entry

• [+] Crossover Design | Wiki Entry

...
More to come.

🎧 Philosophy & Reasoning

I fell in love with IEMs, so I decided "why not, I'm bored."

❓ Can I Use These Files To Build My Own IEM?

Absolutely. I’ve set the license to be lenient for anyone who wants to use this as a base for their own commercial projects—while still keeping that open-source spirit that I’ve grown to love in the comp sci world.

I hope this gives you a head start—maybe even helps you dodge some of the mistakes I made.

Reminder: I’m still human, and this design is far from perfect—but it should give you a solid look at what an IEM build process can look like.

Project Resonator 4 Way Passive Crossover Diagram [For 4BA Driver Configuration]

graph LR
    Input[Source Input] --> Woofer_Path[Woofer Path<br/>CI-22955]
    Input --> Mid_Path[Mid Path<br/>BK-26824]
    Input --> High_Path[High Path<br/>SWFK-31736]
    
    Woofer_Path --> R1[22Ω Series]
    R1 --> C1[4.7µF Parallel]
    C1 --> Woofer[CI-22955<br/>Woofer]
    C1 --> GND1[GND]
    
    Mid_Path --> C2[10µF Series]
    C2 --> R2[22Ω Series]
    R2 --> C3[4.7µF Parallel]
    C3 --> Mids[BK-26824<br/>Mids]
    C3 --> GND2[GND]
    
    High_Path --> T1_Path[Tweeter 1 Path<br/>Damped]
    High_Path --> T2_Path[Tweeter 2 Path<br/>Light]
    
    T1_Path --> C4[2.2µF Series]
    C4 --> R3[6.8Ω Parallel]
    R3 --> Tweeter1[SWFK-31736<br/>Tweeter 1]
    R3 --> GND3[GND]
    
    T2_Path --> C5[2.2µF Series]
    C5 --> R4[22Ω Parallel]
    R4 --> Tweeter2[SWFK-31736<br/>Tweeter 2]
    R4 --> GND4[GND]
    
    style Woofer fill:#1a1a1a
    style Mids fill:#1a1a1a
    style Tweeter1 fill:#1a1a1a
    style Tweeter2 fill:#1a1a1a
    style Input fill:#1a1a1a

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🛠️ Installation Guide

VituixCAD + Fixing Missing File Paths

1. Go to https://kimmosaunisto.net/
2. Find and download latest version
3. Install it and open the .vxp simulation file included in this project

You’ll probably get a bunch of “missing file path” errors—don’t worry. That just means the project is still pointing to paths from my own system.

To fix:

• Click the folder icon next to the .frd or .zma file slot
• Navigate to the correct folder for each BA driver (inside the BA Driver Spec Sheets folder in this repo)
• Re-link the appropriate files

(You only need to do this once.)

Downloading Fusion 360 IEM Shell Files

All IEM shell files are now hosted on MEGA. This includes both .stl files for direct printing and .f3d Fusion files for editing.

Since GitHub has upload limits, I’ve stored them externally here:

🔗 Mega Link For IEM Shell Files

Inside, you'll find:

• Ready-To-Prints | Shell prototypes you can print right away
• Fusion-Shell-Models | Editable Fusion files to tweak however you’d like

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👨‍💻 Author

• Daksh Kaul (aka. DriftingOtter)

🙌 Credits & Citations

• Head-Fi DIY IEM forums & community
• Kozh
• Kirby Meets Audio
• Crinacle
• Mr.T’s Design Graveyard
• And many more...

If I forgot to credit you, shoot me a message—I’ll make sure you’re added.