Ac3 to mp4 free discover this info here: convert ac3 to mp4 online young circumstance download from ac3 to mp4 enough The second thing you'll read is that you should never convert a lower bitrate stream to a higher bitrate stream and hope that it sounds better. You cannot gain quality by increasing the bitrate. This is exactly correct. You will actually reduce the quality of your MP3 file if you try to convert up the bitrate. The following article is a guide shows you how to extract audio tracks from MP4 to MP3 file on Mac OS X, the conversion process is simple and can be done fairly quickly. Let's take a look!