audioOS 9.9.17.4 (build 21L227) is an official Apple over-the-air update for the HomePod, released on 2024-03-07T18:16:19Z. The update package is 1.57 GB. This is a delta (partial) update that requires 15.4.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: bc5b6d58d4a143edf71927ba27ce7dab2093f75e.zip.