The Grace Digital CastDock has a built-in micro-USB cable and 3.5mm cable for your Chromecast Audio, along with a space for it to slide in to. Once docked, you can stream to the CastDock like you would any speaker the Chromecast was connected to, and pair multiple CastDocks for stereo or whole home audio. The CastDock is also mountable, but not portable.
In terms of sound, as other reviewers have noted, there’s too much bass. If you like that, great, but otherwise you’re going to find yourself in the EQ settings more often than not.
At around $90 on Amazon at the moment, the CastDock comes in around $60 cheaper than the best price we’ve ever seen on a Sonos PLAY:1, which is a big difference. If you’re a fan of the Chromecast interface and a fan of bass, this is a great pick for you. That’s especially true if you already own a Chromecast Audio, since it’s sold separately.