There are plenty of ways to turn normal wired speakers into smart speakers connected to your Wi-Fi network. The Chromecast Audio was a popular device for this, until it was discontinued, and Amazon had its own solution in the form of the Echo Input (which also seems to be dead). Popular accessory maker Belkin released its own Wi-Fi speaker adapter earlier this year, aimed at people in the Apple ecosystem, and now you can get it for $85.12. That's a savings of $14.897 from the original price.

The Belkin SoundForm Connect seems to be the only adapter for turning any wired speaker (with 3.5mm or optical cables) into an Apple AirPlay 2 device, at least outside of multi-purpose receivers that cost hundreds of dollars. While there are other adapters that use the original AirPlay protocol, AirPlay 2 adds the ability to play music through multiple AirPlay speakers at once, similar to what Google Cast has offered for a few years. However, you can only create speaker groups with other AirPlay 2 devices, like the Apple HomePod.

This adapter can turn any speaker setup into an AirPlay 2 speaker.
Belkin Soundform Connect

This adapter can turn any speaker setup into an AirPlay 2 speaker.

The sale price of $85 is still a lot for something that serves the same purpose that Google's $35 Chromecast Audio did, but there are fewer options that support Apple AirPlay, especially the newer AirPlay 2 protocol. This is also the lowest price yet for the Belkin SoundForm Connect.