I suggest ImpactJS to have a global media (and code, ie. 'lib') URL prefix setting. This is very useful if you're placing static content to another server or even a CDN, so basically your images and audio are coming from entirely different url.

Unless I'm missing something, this would be a nice feature to have, otherwise you have to put them manually in each ig.Image or ig.Sound call:

foo = new ig.Image(MEDIAPREFIX + 'bar.jpg')

Also, I had to change impact.js because setting ig.lib right after loading impact.js did not change the path.