audioOS 9.9.15.5.1 (build 19L580) is an official Apple over-the-air update for the HomePod mini, released on 2022-05-25T17:17:07Z. The update package is 458.6 MB. This is a delta (partial) update that requires 15.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 34e11713b91610de201a532785ce325700702681.zip.