audioOS 9.9.15.1 (build 19J6572) is an official Apple over-the-air update for the HomePod (Unknown Model), released on 2021-10-25T17:12:16Z. The update package is 1.91 GB. This is a full OTA update that can be applied from any compatible base version. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 092506dde3531cbdad445086eadb899e7e50afda.zip.