audioOS 9.9.18.1 (build 22J580) is an official Apple over-the-air update for the HomePod (2nd generation), released on 2024-10-28T15:30:09Z. The update package is 1.38 GB. This is a delta (partial) update that requires 16.3 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: e2115627d7da04d0688a8c2db6362ae34e11e5ab8404bdc5596052e9f9b62220.aea.