I haven't tried 4X recording yet. I have only used mode 2, which, is 2 times as much. At that setting, the MD recording still sounds better then the average 128K mp3. So at least at the 2x setting, you cannot tell the difference. From what I hear, 4x is fairly similar, discernable only by more "demanding" listeners. I have a Sony MZR-900, btw.