Send any audio to the AirPort Express. Send any audio to AirPort Express units, Apple TVs, and even other Macs and PCs, all in sync! Airfoil for Mac gives you your audio - everywhere. You can send audio to multiple outputs around your house, all in sync, and with Airfoil Speakers, you can turn any computer into a remote audio output.
With Airfoil, you can transmit any audio from your computer out to compatible receivers, which are: Apple TVs, Windows, Mac and Linux computers, Android and iOS devices, Third-Party AirPlay Devices.
(Free trial version adds noise after 10 minutes of transmission.)