I\'ve been reading up on event passing in Angularjs and I\'m not convinced that using $broadcast is a good idea.
Blogs like this one advocate getting used to $on eve
I was looking at this same problem. Particularly how to allow services to broadcast and subscribe to events without accessing $rootScope (bad for a few reasons). I utilized the very excellent js-signals implementation from here : http://millermedeiros.github.io/js-signals/ and wrapped it into an angular service.
github gist here : https://gist.github.com/anonymous/b552c7fafa77427e6d06