What is Wireless Multi Room Audio?

With many of the benefits of a wired multi room entertainment system, a wireless multi room audio system allows you to listen to your digital music library stored on your PC, MAC or Networked Attached Storage device from anywhere in the home but without the need to 'plumb' cables into the ceilings and walls.

Sonos Digital Music System - click for details
Sonos is the first and only digital music system that lets you play all your digital music, all over your house—and control it all from the palm of your hand. Best of all, you don't need a PC in every room, a music server or a wireless network. Just a SonosTM ZonePlayer and speakers in the rooms of your choice and a SonosTM Controller in hand to access all your digital music, no matter where it's stored—on your PC, Mac or Network Attached Storage box.

For more complex systems involving multiple audio sources and video, please look at Multi-room entertainment