audioOS 9.9.18.4.1 (build 22L261) is an official Apple over-the-air update for the HomePod (2nd generation), released on 2025-04-16T17:28:47Z. The update package is 1.28 GB. This is a delta (partial) update that requires 17.1.1 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: 3bee79fc371c0180897769548c41ac37eac233a1f0c3914670a9d3377dbed1d9.aea.