Nice short explanation A440. And about "Atrac 3" at 66 kbps and "Atrac 3 Plus" at 64 kbps, I would stick to the newer one, Atrac3+, which uses a more advanced compression algorythm. What I do, (which is overkill) is to decompress my Mp3s to Wav PCM, usually with Winamp so I can use the Auto-Preset equalizers and DSP plugins in my Mp3s and equalize/normalize each song exactly the way I want to hear it. Then import them in SS and compress them in my bitrate of choice. It's interesting to see who bad SS treats already compressed files (read mp3, wma..) or other codecs in comparison with an uncompressed wav-file. It seems SS can't handle a good re-compression. I've found much better sounding results this way.