In Logic Pro 9 you can load a song and it will make the frequencies that are present into a template so that it's EQ can be replicated. But that's a long way from what mastering a song from scratch would be. There are so many other aspects to mastering, and listening a pro song and trying to match the sound isn't as easy as it would seem although not impossible. I've heard some homemade stuff that was as good as any studio, but if I was needing a pro sound I would use a pro studio. I'm just a hobbyist so I don't need perfection to have fun.