AVCLabs Audiobook Converter
AVCLabs Audiobook Converter for Mac is the best AA Converter.
Macsome AudioBook Converter for Mac
convert any audio book to mp3, aac in 5x fast speed, with id tags preserved
Macsome iTunes Converter for Mac
convert m4p, m4a, aa to mp3 or aac in 10x fast speed, with id tags preserved.