Comparison of Audio Encoders
The aim here is to choose a compression format with which to encode an entire CD collection for easy access in a media center.I've taken a typical 4 minute song and encoded it using LAME mp3 and iTunes AAC at various bit-rates and then analysed their spectral content and compared them with the raw original.
Combined with a subjective listening test and accounting for the size of a typical collection and storage capacity, I recommend 256k AAC.

The song used was 'Countings Crows - Hard Candy'