Sonos' ZonePlayer 90 is a network-enabled digital music player optimized for use with other Sonos components. The 90 communicates with other Sonos products over an AES-secured wireless mesh network. Rather than overwhelm the area with high-power RF broadcasts, the devices use a peer-to-peer system, each communicating directly with only devices nearby. At least one player, or the optional ZoneBridge wireless bridge, must be connected to a wired network, however. The 90 is a similar to the ZonePlayer 120, but has no internal amplifier, so it must be connected to another receiver. It's quite bare-bones when it comes to connections and controls: it offers only volume adjustment buttons and features only a network connection, analog and digital audio-in, and line outputs. Real control is done remotely, through either PC software, the CR100 wireless controller, or an iPhone app.

The ZonePlayer streams a solid variety of audio formats, including MP3, AAC, Ogg Vorbis, and FLAC. In addition to playing music archived on a local PC, the 90 can connect to interent radio stations like Pandora and Last.fm to play live feeds. The model's $350 price tag is on the steep side, however, as Logitech's SqueezeBox offers similar functionality for under $300 and adds a remote and display to the unit.