Multiple iTunes Instances on OS X

October 22, 2013

On the Mac it is possible to run multiple iTunes instances at the same time by running each one under a separate OS X user account. With each instance connected to a different set of AirPlay speakers this allows for a nice multi-zone setup with a single Mac. To use Signal in this configuration start a Signal instance for each user account and they will automatically connect to the appropriate iTunes instance. By default Signal will choose the next available port starting from 3569, to lock each instance to a specific port you can use a hidden default by running the following command in Terminal:

defaults write com.alloysoft.Signal HTTPPort -int 3570

Replace last argument in the above example with the port number you wish to use. You can then create a bookmark for the web interface using the desired port or specify this port in the RTI driver configuration starting with driver version 1.6.