Chromecast Audio’s multi-room support has arrived, along with high-res audio

As promised, Google’s Chromecast Audio now serves as a cheap solution for whole-home audio. The $35 device, which launched in September, brings Internet music sources such as Pandora and Spotify to any “dumb” speaker over 3.5mm, RCA, or Optical input. Users control playback by opening streaming music apps on a phone, tablet, or PC, and hitting the