https://techcrunch.com/2019/09/25/amazon-refreshes-the-echo-with-improved-sound/

Amazon’s just getting started with the new hardware this morning. In addition to the Echo Dot With Clock (which, as mentioned, is an Echo Dot that has a Clock), the company refreshed the baseline Echo. Once again, the refresh revolves around improved sound.

The new version incorporates audio improvements introduced on the Echo Plus, though it doesn’t appear to have the Plus’s Hub functionality built in, leave the two products distinct. The new audio hardware includes neodymium drivers, more volume and a stronger midrange.