Can someone help me out? Back in 2004 when I got my first iPod, I imported all my CD's at 128kbps AAC (M4A), I heard this is the equivalent to 256kbps MP3, is this true? I am working with some pretty decent KRK V4 monitors but to be quite honest I can't tell the difference b/w 128kbps AAC vs. 320kbps MP3. I am not an audiophile but I do want to make sure all the CD's I've imported are high quality rips. Let me know your thoughts, thanks!