81 lines
3.7 KiB
Markdown
81 lines
3.7 KiB
Markdown
# 🔊 3D Printed Multi-Room Smart Speaker
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A complete guide to building a custom-designed, 3D-printed smart speaker. This project leverages a Raspberry Pi Zero 2 W for the client hardware and uses Music Assistant with Snapcast for sub-millisecond multi-room audio synchronization.
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## ✨ Features
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* **Acoustically Optimized:** Custom 3D printed enclosures designed to eliminate standing waves.
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* **Perfectly Synced:** Snapcast integration ensures multi-room audio with zero echo.
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* **Centralized Control:** Managed via Music Assistant and Home Assistant.
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* **Low Power:** Client nodes run on highly efficient Raspberry Pi Zero 2 W boards.
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---
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## 🛠️ Hardware Prerequisites
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### The Client (Speaker Node)
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* **SBC:** Raspberry Pi Zero 2 W
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* **Audio Output:** HiFiBerry AMP2 (or similar I2S DAC/Amp HAT)
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* **Drivers:** Raw speaker drivers (T/S parameters required for volume calculation)
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* **Power:** High-quality 5V power supply
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* **Hardware:** M3 heat-set brass inserts, M3 machine screws, Poly-fil (pillow stuffing), and adhesive weather-stripping (or TPU for a printed gasket).
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---
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## 🖨️ 3D Printing the Enclosure
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To achieve true high-fidelity sound rather than a hollow plastic echo, the enclosure must be rigid, airtight, and acoustically tuned.
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### Acoustic Design
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1. **Calculate Volume:** Start with a **sealed enclosure**. Use the Thiele/Small (T/S) parameters of your chosen speaker driver to calculate the exact internal volume required.
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2. **Ditch the Cube:** Model the enclosure with swept curves, spheres, or teardrops. Curves prevent internal standing waves and add massive structural rigidity.
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3. **Thick Baffle:** Design the front face (where the speaker mounts) to be 15mm - 20mm thick.
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### Slicer Settings
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* **Material:** PETG, ABS, or ASA. (Avoid PLA as it creeps under screw pressure and warps in heat).
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* **Walls over Infill:** Aim for 3-4 perimeters to achieve a 2mm-3mm solid shell. Total wall thickness should be roughly 8mm-10mm.
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* **Infill:** 15% - 40% Gyroid or Cubic infill for multi-directional strength.
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### Assembly
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* Melt heat-set inserts into the mounting holes to prevent screws from backing out under vibration.
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* Apply a gasket between the driver and the printed baffle to ensure an airtight seal.
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* Loosely pack the interior with Poly-fil to slow internal sound waves and improve bass response.
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---
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## 💻 Software Deployment
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### 1. The Server (Control Plane)
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Music Assistant handles both the media library and the Snapcast server. Deploying via Docker Compose is the cleanest method for a dedicated server environment like TrueNAS.
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**Crucial Note:** You *must* use `network_mode: "host"` so Music Assistant can dynamically allocate TCP ports for incoming audio streams without Docker bridge bottlenecks.
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```yaml
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services:
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music-assistant:
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image: ghcr.io/music-assistant/server
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container_name: music-assistant
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restart: unless-stopped
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network_mode: "host"
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volumes:
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- /path/to/your/appdata/music-assistant:/data
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# Mount your local media directories (e.g., from your ZFS pool)
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- /path/to/your/media:/media:ro
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```
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### 2. The Client (Pi Zero 2 W)
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1. Flash the Pi Zero 2 W with a lightweight OS like **Raspberry Pi OS Lite**.
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2. Install the Snapcast client daemon:
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```bash
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sudo apt update
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sudo apt install snapclient
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```
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3. Configure `snapclient` to point to your Music Assistant server IP, connecting on port `1704`.
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4. Configure your `/boot/config.txt` to enable the I2S overlay for your specific DAC/Amp HAT.
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---
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## 🌐 Network Requirements
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* **Server:** Wired Ethernet is highly recommended.
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* **Clients:** A strong, stable 2.4GHz Wi-Fi connection.
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* **Ports:** TCP `1704` (Audio Stream) and TCP `1705` (Control/JSON-RPC) must be open.
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