AAC vs. MP3 format and conversion

Q: Can you tell me the advantages of using the AAC format compared to using MP3? If AAC is better for clarity or what not, can I convert my whole library in a few simple steps? What’s involved in making that happen?

– Tom

A: AAC is said to offer better quality than MP3 at the same bit rate. That said, if you already have a lot of music in MP3 format, it’s not worth changing it. First, if you convert your music from MP3 to AAC, you’ll probably lose quality; at best, the music will sound as it did in MP3 format; at worst, the fact that iTunes has to decompress then recompress the music will make it sound worse.

You can certainly re-import your CDs to AAC format if you wish, and replace your MP3 files. For most purposes, AAC files at 160 kbps sound excellent; about as good as 192 kbps MP3 files. This means you save a bit of space using lower bit rate files.

However, if you think you might ever want to listen to your music on a non-Apple music player, don’t convert your music to AAC. Very few music players other than the iPod currently support AAC, though this may change in the future.

Kirk McElhearn is the author of several books including iPod & iTunes Garage.