I just read Audiodudes update to this thread. Sonar is my current universe so I tried out R-Mix. What a great tool! I spend a lot of time trying to transcribe parts from songs and sometimes it's hard to hear them because they're masked by other parts, although his original post is still right on WRT unbaking the cake, R-Mix is a great way to cancel things that dominate the mix to find the bits that are hard to hear. Thanks to Audiodude for pointing out a great tool, I never would have even bothered with it until I read his post.