February 10, 2012, 1:46 PM — Here's how you can convert large AIFF audio files into compressed M4A files on your Mac for free. This uses the Mac's built-in ability to encode files, you won't need any special software.
1. Find the AIFF audio file you want to convert and then right-click it.
2. Choose the Encode Selected Audio File selection from the right-click menu.
3. A window will pop up and you should choose iTunes Plus for the encoder in the drop down menu.
4. You can change the destination for your converted file if you want.
5. Click the Continue button to begin converting your file.
For more, see the original article at the link below.

Convert AIFF to M4A Directly in Mac OS X Easily & For Free
| OS X Daily














