audioOS 9.9.17.0 (build 21J354) is an official Apple over-the-air update for the HomePod, released on 2023-09-18T17:26:24Z. The update package is 1.5 GB. This is a delta (partial) update that requires 15.4 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: c911b844b4f7589ceaf653e5b167be421e462ce8.zip.