Preferences

Interfaces:
Show:
Adjust the content of the Audio Source popup menu at the bottom of Airfoil's main window. All sources are on by default.
Applications - Toggles display of applications. It's unlikely you would want to turn this option off.
Widgets - Toggles display of widgets (OS X 10.4 and up only).
Audio Devices - Toggles display of audio input devices.
Radio Devices - Toggles display of radio devices such as the RadioShark.
System Audio - Toggles display of the System Audio output options, which requires SoundFlower. See the Install Extras... window under the Airfoil menu for more details.
Minimize To Menu Bar:
When active on OS X 10.4, Airfoil will be minimized to the Menu Bar instead of the Dock. Option-clicking the minimize button reverses this behavior.

Automatic Speakers:
Automatically transmit to: - When launched, Airfoil will immediately begin transmitting audio from the last selected application to the selected remote speakers. Uncheck all boxes to turn off automatic transmission of audio.

Speaker Synchronization And Playback
Total Synchronization - When selected, Airfoil will manipulate audio in largely inaudible ways to keep playback between multiple units synchronized. This is the default and recommended setting for multiple speaker setups.
Pure Playback - When this option is selected, audio will be sent to the AirPort Express with absolutely no manipulation. Airfoil will not attempt to keep playback between multiple units synchronized.

Software Update:
Automatically check for updates - With this on, Airfoil compares its own version number with the most current version available from our server. Please leave this on to stay up-to-date.