audioOS 9.9.15.2 (build 19K52) is an official Apple over-the-air update for the HomePod mini, released on 2021-12-13T18:28:32Z. The update package is 307.45 MB. This is a delta (partial) update that requires 15.1.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 32d7a3a80cb3ad20b4f7731cae0b4e11a0afc959.zip.