TL;DR
Nabu Casa’s Home Assistant Connect AUX-2 is an audio streamer for connecting speakers or amplifiers to Home Assistant through Music Assistant. A Matter Alpha reviewer found its Ethernet and PoE, digital and analog outputs, and ESPHome expansion useful, while noting slower playback starts and less responsive grouping than established systems.
Nabu Casa has released the Home Assistant Connect AUX-2, an audio streamer designed to connect existing speakers or amplifiers to Home Assistant’s Music Assistant. In a review published by Matter Alpha, the device was praised for its wired network and power connection, flexible audio outputs and hardware expansion options, though the reviewer also reported slower playback starts and less responsive speaker grouping than established alternatives.
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The AUX-2 uses Sendspin and offers analog and digital audio through the same 3.5 mm jack, with the output format handled automatically according to the cable used. The reviewer tested it with an IKEA SOLSKYDD speaker and preferred the digital connection, reporting better sound and less susceptibility to noise from loose connections or grounding. The output options also make the device relevant to people with dedicated amplifiers, not just compact speakers.
Ethernet with Power over Ethernet (PoE) lets one cable supply both network access and power. In the reviewer’s test, Home Assistant detected the unit soon after it was connected by PoE, and the standard setup took about half a minute. Wi-Fi setup was also possible through a phone and the Home Assistant companion app. For ordinary use, the reviewer said there was no need to configure the device in ESPHome Builder.
More advanced customization is available through ESPHome, but requires additional configuration. The device also includes USB, serial and Grove connections. The reviewer used a Grove port with a custom ESPHome setup to connect an RGB LCD that displayed song information and playback progress. USB could also support compatible Zigbee or Z-Wave coordinators, although the review describes the ZHA experience as experimental.
A Wired Route to Home Audio
The AUX-2 offers Home Assistant users a way to add networked playback to existing speakers and amplifiers, rather than replacing them with a new, self-contained smart speaker. PoE can simplify placement where power outlets are inconvenient, including locations near ceiling speakers or other fixtures. A wired connection can also help households avoid relying on busy Wi-Fi networks for continuous audio.
The product’s appeal depends on what a user needs. People seeking a simple streamer can use its managed setup without changing firmware. Tinkerers can connect accessories and customize behavior through ESPHome. Those choices give the device a wider range of potential uses, but they do not mean every expansion feature is ready for ordinary use: the reviewer specifically describes coordinator support through ZHA as experimental.
The review also found that Sendspin playback has limitations. Music generally sounded solid once it was playing, and the reviewer reported close synchronization among grouped speakers during continued playback. However, playback often took longer to start, and grouping or ungrouping felt less responsive than with AirPlay. That distinction matters for buyers comparing the AUX-2 with mature audio systems: its flexibility and Home Assistant integration come with some differences in day-to-day responsiveness.
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From Sendspin to Home Setup
The Connect AUX-2 is built around Sendspin, an open audio project, and is intended to bring its capabilities into a more finished consumer-facing device. Its combination of networked audio, PoE and expansion connectors sets it apart from simpler compact options. The review compares its broader connectivity with community-oriented products such as Apollo Automation’s Cast-1, but does not provide a price comparison or a controlled head-to-head performance test.
Home Assistant manages the AUX-2 as an integrated device, including its firmware updates, according to the reviewer. That lowers the entry barrier compared with projects that require owners to flash and maintain firmware themselves. Optional ESPHome configuration remains available for functions such as changing audio codecs or adding voice-related features and displays, while requiring more technical work.
“The audio quality is solid.”
— Matter Alpha reviewer
Performance Depends on Setup
The review reflects one reviewer’s several weeks of use, not a broad test across different networks, amplifiers or speaker configurations. It does not establish how often users will encounter slow starts or grouping delays, or how performance will vary with different Wi-Fi conditions. The reviewer found Ethernet more reliable in a crowded wireless environment and reported that selecting the Opus codec through ESPHome improved Wi-Fi performance, but said this did not eliminate every possible wireless issue.
Some expansion uses also have limits or require more testing. The review calls the ZHA experience experimental and says the reviewer was waiting for possible OTBR support alongside the ZBT series. It does not confirm a release date or availability for that capability. The source also offers no pricing, broader availability details or comparative measurements against competing streamers.
Firmware and Expansion Tests
For users considering the AUX-2, the most direct next step is to match its connection options to their setup: use PoE and Ethernet where a wired run is practical, or consider the reviewer’s ESPHome codec adjustment if using Wi-Fi. Custom display and accessory projects will require additional configuration, and buyers interested in coordinator support should account for the review’s warning that ZHA remains experimental.
Further testing and firmware development may clarify how Sendspin performance evolves and which expansion features become practical for more users. The review does not give a schedule for updates or for OTBR support, so those developments remain open rather than confirmed product milestones.
Key Questions
What does the Home Assistant Connect AUX-2 do?
It streams audio through Music Assistant to an existing speaker or amplifier, using Sendspin and Home Assistant integration.
Does the AUX-2 need Ethernet?
No. The review reports that Wi-Fi setup is available through the Home Assistant companion app. Ethernet with PoE can provide network access and power through one cable, and the reviewer found it more reliable than Wi-Fi in their crowded network.
Can it connect to digital audio equipment?
Yes. It supports both analog and digital audio through the same 3.5 mm jack. The reviewer used a different cable to switch formats and preferred digital output in their test.
Do users need ESPHome to use the AUX-2?
The reviewer said standard setup and use did not require ESPHome Builder. Custom features, including codec changes and connecting a display, require additional ESPHome configuration.
What limitations did the review identify?
The reviewer reported that playback could take longer to start and speaker grouping could feel less responsive than with AirPlay. They also described ZHA coordinator support as experimental; results may vary by setup.
Source: matteralpha.com
