https://techcrunch.com/2018/09/20/amazon-introduces-a-new-subwoofer-and-amp-for-the-echo-line/

The Echo Sub isn’t quite a HomePod competitor, but it’s pretty darn close. In fact the the Amazon-made subwoofer actually looks a far bit like Apple’s high-end smart speaker. But the device is actually designed to work in conjunction with the Echo line, offering a much deeper sounds than any of the current devices.

Along with the Sub, the company rolled out two more products, the Link and Link Amp, both designed to make the company’s smart products a fuller part of the home sound system. The offering is an interesting one for users who already own an Echo device, helping them improve the sound of the products, without forcing them to start from scratch with a self-contained product.