If you can’t choose your remote speakers
When you have speakers connected to an AirPort Express, a pop-up menu appears at the bottom of the iTunes window so that you can choose which speakers to use.
Make sure that:
Your AirPort Express is properly plugged into a working power outlet.
Your remote speakers are properly connected to your AirPort Express.
â€œLook for remote speakers connected with AirTunesâ€ checkbox is selected in iTunes preferences (choose EditÂ > Preferences and click Devices).
Your computer is in range of your wireless network (if you’re using one) and your AirPort Express is joined to the network and is active. Click the Wireless Network system tray and make sure your network is selected.
If you’re still having trouble, see the Apple Support website (click the link below), or check the documentation that came with your AirPort Express.