What is it?
The Esparagus Audio Brick is a high-fidelity, modular audio endpoint built for makers, smart home integrators, and audio enthusiasts. It combines an ESP32 core, the TAS5825M DAC/amp, and robust connectivity (Ethernet/WiFi) into a DIN-rail mountable board that supports stereo, mono, bi-amp, or subwoofer configurations. With over-the-air updates, full DSP control, and an open software stack, it bridges the gap between DIY audio and professional installations.
Crowd Supply
Our Crowd Supply campaign is live! Please consider backing this project to make this product go live.
Dual DAC model (prototype)
I’m currently working on the dual DAC variant of the Audio Brick. Its main feature is a second TAS5825M DAC that is connected to the same I2S line (so it is perfectly synced with the primary DAC), but allows flexible configuration as either additional 2 channels of audio, a more powerful subwoofer channel, or even a bi-amp configuration, with each DAC driving one speaker (one driver per channel).
Software was a little problematic at the beginning, as most open source projects would not expect two I2C-controlled DACs at the same time, but with the power of ESPHome, it was made possible, so the Audio Brick exposes a single audio sink, with precise control over each DAC configuration, volume, filters, and mixer configuration.
Use cases
Esparagus Audio Brick is a flexible, open-source audio platform designed to fit into both smart homes and custom audio projects.
- Smart Home Audio & TTS
Integrates with Home Assistant and Music Assistant for high-quality audio playback and text-to-speech announcements. Perfect for notifications, voice alerts, and whole-home audio driven by your smart home automations. - Multi-Room Audio with Snapclient
Use the Esparagus Audio Brick as a Snapclient endpoint to create perfectly synchronized multi-room audio systems. Ideal for distributed music playback without proprietary lock-in. - Standalone Player with Squeezelite-ESP32
Run Squeezelite-ESP32 for a self-contained network audio player supporting Spotify Connect, AirPlay, and Logitech Media Server (LMS) — no external computer required. - Educational Projects & Teaching Platforms
A powerful tool for schools, universities, and technical education. Esparagus Audio Brick can be used to teach embedded systems, digital audio, networking, and open-source software, ranging from simple audio playback labs to advanced DSP, streaming, and real-time systems projects. - Research, Prototyping & Experimentation
Well-suited for rapid prototyping of audio devices, proofs-of-concept, and research projects involving DSP, low-latency streaming, wireless audio, or human-machine interaction. - A Foundation for Custom Products & DIY Builds
With all firmware and tooling fully open source, Louder-ESP32 is an ideal base for custom audio devices — whether you’re building a personal DIY project, a small production run, or a community-driven product.
Which chip: ESP32 or ESP32-S3?
Most boards in this line are sold with either the ‘classic’ ESP32 or the newer ESP32-S3. They are not interchangeable for every use case, and picking the wrong one is the single most common support question — here’s the short version:
- ESP32-S3 is the newer, more capable chip — more RAM headroom, a faster CPU, and native USB — but it has no Bluetooth Classic radio, so Bluetooth A2DP only works on the original ESP32.
- Squeezelite-ESP32 and standalone Snapclient: pick the classic ESP32. Neither firmware is fine-tuned for the S3 yet, and current S3 support is noticeably laggier.
- ESPHome / Home Assistant media player: pick ESP32-S3. The new Sendspin renderer runs much better on the S3’s extra headroom.
- Voice assistant (wake word) in Home Assistant: ESP32-S3 is mandatory — the classic ESP32 doesn’t have the RAM/CPU headroom to run it.
- AirPlay 1 & 2 (rbouteiller/airplay-esp32): both chips are fully supported on the boards it currently targets; ESP32-S3 is preferred for its extra performance headroom.
| Your use case | Pick |
|---|---|
| Bluetooth A2DP from a phone/laptop | ESP32 |
| Squeezelite-ESP32 or standalone Snapclient | ESP32 |
| ESPHome media player / Sendspin | ESP32-S3 |
| Home Assistant voice assistant | ESP32-S3 |
| AirPlay 1 & 2 | Either — ESP32-S3 for more headroom |
If none of that applies to you and you just want the safe default, pick ESP32-S3 — it’s the newer chip. Only choose classic ESP32 if you specifically need Bluetooth A2DP, or plan to run Squeezelite-ESP32/Snapclient today.
Features
| Louder-Esparagus | Esparagus Audio Brick | Esparagus Audio Brick Dual DAC | |
| MCU | ESP32-WROVER-N8R8 | ESP32-S3-WROOM-N8R8 | ESP32-WROVER-N8R8 | ESP32-S3-WROOM-N8R8 | ESP32-S3-WROOM-N8R8 |
| DAC | Stereo I2S DAC (TAS5805M) with built-in D-Class amp | Stereo I2S DAC (TAS5825M) with built-in D-Class amp | |
| Output (4Ω, 1% THD+N) | 2x 32W | 2x 45W | 4x 45W |
| Output (8Ω, 1% THD+N) | 2x 23W | 2x 30W | 4x 30W |
| Output (Bridge, 4Ω, 1% THD+N) | 1x 45W | 1x 53W | 2x 53W |
| Flash/PSRAM | 8MB/8MB | 8MB/8MB | 8MB/8MB |
| Connectivity | WiFi + BT4.2 + BLE + Ethernet | WiFi + BT4.2 + BLE + Ethernet | WiFi + BLE + Ethernet |
| Optional Peripherals | 0.96″, 128 x 64 px OLED Screen | 0.96″, 128 x 64 px OLED Screen | 2.0-2.4″, 320 x 240 px TFT Screen |
⚠️Louder boards will connect to passive speakers; you can’t use headphones or an external amp
💡Need to connect an external amp? Check out HiFi-ESP32 and Amped-ESP32
💡Don’t need DSP capabilities? Check out Loud-ESP32
Optional Peripherals
- WS2812B RGB LED
- W5500 Ethernet
- Software-controlled FAN connector (DUAL only)
Other
- 90 x 90 x 40mm DIN-rail mountable case (125 x 90 x 40mm for DUAL model)
- Plug-in connector pairs for input/output/power, to make installation and replacement easier.
- Improved thermal design for enclosed spaces.
Onboard PSRAM
Audio streaming requires proper buffering to work, even with the ESP32’s 500K of RAM; it is a challenging task. For that reason, all Louder-ESP32 board versions have an 8 MB PSRAM chip onboard, connected via a high-speed interface.
Use Cases
- Retrofitting legacy or passive speakers: give old speakers streaming, multiroom, and smart home ability without replacing them.
- Whole-house or multi-zone audio installs: DIN-rail mounting & modular Bricks let you distribute clean, manageable audio per room or zone.
- Commercial or semi-industrial environments: clean wiring, reliable connectors, and ease of replacement make maintenance and scaling feasible.
- Enthusiast setups: bi-amp, subwoofer support, and 15-band EQ let you fine-tune the system to your audio gear.
Comparison to Earlier Models
- Moves from TAS5805M to TAS5825M for better efficiency/power/features.
- Adds mechanical and thermal improvements (DIN-rail support, better heat dissipation).
- Improved connector design for maintenance & swap-out.
- Focused on scalability: multi-unit, whole-home use-cases rather than single standalone speaker boxes.
Firmware
- Home Assistant
Start from the web-installer, as soon as you configure WiFi, the boards will be discovered by the ESPHome add-in automatically. Dedicated configs can be found in the documentation for simple and stable media-player, experimental sendspin protocol, and experimental snapclient component - AirPlay 1 & 2 with Sendspin and Bluetooth. Native, actively developed AirPlay 1 & 2 firmware (rbouteiller/airplay-esp32) with PTP multi-room sync, an experimental Sendspin renderer, and Bluetooth A2DP on the ESP32 revision. Flash straight from your browser with the web-installer — no toolchain needed. See AirPlay 2 support below for details.
- Squeezelite-ESP32
Flash directly from your browser using the web-installer, configure WiFi using Hotspot (default password: squeezelite). Don’t forget to exit Recovery mode when configured. - Snapclient
Flash directly from your browser using the web-installer, as soon as you configure the WiFi board, it will discover the snapserver automatically - Snaplient (edge)
The developer’s version of the snapclient is less stable and more feature-rich for those who cannot wait for new features to be released. Installed via web-installer, similar to standard snapclient - Your own software
Use Arduino IDE or Platformio IDE and the provided software samples
AirPlay 1 & 2
Squeezelite’s built-in AirPlay is a first-generation implementation. rbouteiller/airplay-esp32 is a standalone, open-source AirPlay 1 & 2 receiver for the ESP32 family — actively developed, with great work done by the community despite the lack of help from Apple.
It now supports HiFi-ESP32, Loud-ESP32, Louder-ESP32, and Louder-ESP32-Plus, and Amped-ESP32 out of the box, on both the ‘classic’ ESP32 and ESP32-S3 revisions, flashable straight from a browser — no toolchain required. Current features:
- AirPlay 1 & 2 — appears natively in Control Center and any AirPlay app, with PTP-based multi-room sync
- Sendspin (experimental) — an open multi-room protocol renderer sharing the same output path, DSP, and volume control as AirPlay
- Bluetooth A2DP on the classic ESP32 revision — phones and laptops can stream directly whenever AirPlay is idle (the ESP32-S3 has no Bluetooth Classic radio)
- On-device display — the optional OLED add-on, or the Louder-ESP32-Pro’s color TFT, shows track metadata and progress for AirPlay, Bluetooth, and Sendspin alike
- USB audio (UAC) — the ESP32-S3 revision can be built as a USB sound card for a connected computer, sharing the same DAC path
- Full DSP control on Louder-ESP32/Louder-ESP32-Plus — the TAS5805M/TAS5825M’s on-chip EQ is fully exposed: 15 cascaded biquad sections per channel, each an arbitrary peaking filter, shelf, high/low pass, band pass, notch, phase shift, or raw coefficients, plus a crossover builder (and, on the TAS5825M, full PurePath Console 3 tuning replay)
TAS58xx DSP: full parametric EQ and crossover control
AirPlay 2 support above isn’t just playback — it exposes the TAS5805M’s on-chip DSP in full from the board’s web UI:
- 15 biquad (BQ) filters per channel, usable as a full 15-band parametric equalizer
- Bi-amp filter configuration for 2-way speaker systems — split the signal between tweeter and woofer with independent filter chains per amplifier
- Low-pass filtering for subwoofer tuning and bass enhancement
- Generic filters for speaker and room equalization — peaking filters, shelf filters, and EQ sections with a configurable Q-factor, applied per channel individually or to both at once
Work in progress: REW (Room EQ Wizard) integration, to drive automatic room-correction algorithms directly from a measured response.
Using with Home Assistant
Both HiFi Esparagus versions were created specifically to be used with Home Assistant via ESPHome integration. For both boards, rich configs were pre-created with hardware configuration for common use cases. These include
- media_player component for simple and robust media playback and TTS announcements (with ducking effect)
- Sendspin media player – new experimental protocol for multi-room sync with media controls and more
- An experimental snapclient component that allows near-perfect multi-room sync and seamless integration with Music Assistant
- Another snapclient fork with an implemented 15-band software equalizer and a rich set of EQ presets
- Voice assist config for S3-based boards, allowing local voice-controlled assist and automation
Configurations are being actively maintained and upgraded, new experimental components added for you to test and enjoy
Documentation
Both software and hardware are fully open-sourced and can be found on the project’s GitHub. You can follow the project updates at Hackaday
Video overview
Where to Learn More / Get Involved
- Driver repos on GitHub
- Documentation & schematics on Github
- Crowd Supply campaign pre-launch
- Community discussions (Discord / Hackaday)
Where to buy
You may support our work by backing this project on Crowd Supply ($59 MRSP).
As soon as the campaign is finished and all backer orders fulfilled, Audio Brick will become available through Tindie as well
Sponsorship & Community Support
If you’re working on an open-source project, an educational initiative, or any pro-bono/volunteer effort, feel free to reach out for sponsorship details. I’ll do my best to provide discounts or even free boards.
Custom Design & Consultation
If you’re interested in a custom design based on or inspired by my boards, I also offer contract design work and consultation when needed.
In the press
Will This Make My Smart Speakers Smell Funny? – Hackster.io
An Audio Brick For Your Smart Home – Hackaday
Esparagus Audio Brick ESP32-based DIN-rail 65W Hi-Fi amplifier supports Home Assistant and Squeezelite (Crowdfunding) – CNX Software
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