The following audio file formats are supported:
The Mac version can open existing .aac, .ac3, .mp4, .aifc, .caf, .snd, .au and .sd2 files.
WAV files can be used with almost any program that supports audio. You need a WAV file to create an audio CD.
AIF files are similar to WAV files. They're widely supported on Mac computers, but rare on Windows.
GJM/GJS files use lossless compression to reduce file size. The compression algorithm works best if the audio signal doesn't contain loud treble parts. This works well for multitrack recording since tracks typically have many silent or soft parts so the file size can easily be reduced to about 70% of its original size.
Note that sound quality isn't impaired in any way by the compressing action: if you save a .WAV file in .GJM format and then save that file in .WAV format again you get exactly the same file.
M4A files use a lossy compression algorithm that degrades sound quality. Sound quality tends to be slightly better than MP3.
The Mac version supports lossless 'ALAC' compression.
MP3 files use a lossy compression algorithm that degrades sound quality. The resulting file size is 3..9% of the original size. This makes MP3 the format of choice if you want to publish your songs on the internet, or if you want to send them via email.
Every time a new MP3 file is created the audio quality can be chosen: Medium, High, Higher or Very High. These options correspond to 56, 128, 192 and 256 kb/sec (stereo files) or 32, 64, 96 and 128 kb/sec (mono files).