you can use Soundflower (free) to route any output to the ProPhase input.
http://www.cycling74.com/products/soundflower
Download page:
http://www.cycling74.com/downloads/soundflower
also check out the ProPhase forum page:
http://forum.katsurashareware.com/
-author
ProPhase
displays phase & level of stereo audio signals in real time
Version: 1.2