Yahoo Audio Search gives you a broader range of mp3's and other audio files from the entire internet. So, you have to weed through some of the results to find sermons on tithng. I prefer this, due to the fact that it comes up with many more results than Sermon Audio, and most of the sermon search results are free to download or listen to.

On the other hand Sermon Audio Search deals specifically with Sermons. So you don't have to weed through a bunch of general search results. The sermons are free to listen to or download, once you register your email with them. Overall you will not have as much of a variety of results compared to Yahoo Audio Search.