Hello,
they have to talk to each other to stream iTunes to your stereo.
Best to setup the Express:
- Disconnect your Mac from wireless
- Attach the Express via LAN-Cable to the Mac
- Open Airport Utility
On the config. menu of the Express:
- Go to Airport and give the Express a name.
- Give the Express a password if needed
- Go to "wireless" and check "join a existing network"
- Choose the Extreme (your network)
- Go to Musik, give a speaker name and check "activate Airplay"
- Click UPDATE
- Disconnect the LAN Cable
Reconnect your Mac to normal network
After the status LED on the Express went green (could take a minute or two)
Go again to Airport Utility and check that's the Express show up there.
Go to iTunes, choose Speaker (down right) start a song and enjoy :-)
Alternative way to setup:
- Plug the Express to a socket
- Wait for the Express showing up in Airport Utility
- Choose the Express
- Confirm "You're sure to switch to the .."
- Click manualy setup
- Follow the steps mentioned in the first way above
- Disconnect from wireless
- Reconnect to usual wireless
- Start iTunes and enjoy
Personally, I would prefer the first way by plugging a LAN Cable to the Express. It's the easy way.
Cheers - Lupunus