If you use AIFF or WAV encoding, you can use custom settings for greater control over the quality and size of imported files.
To choose AIFF and WAV import settings:
ChooseÂ iTunesÂ > Preferences, click General, and click Import Settings.
Choose AIFF Encoder or WAV Encoder from the Import Using pop-up menu.
Choose Custom from the Setting pop-up menu.
In the dialog that appears, choose settings:
Sample Rate: The number of times per second the music waveforms are captured digitally. The higher the sample rate, the higher the quality and the larger the file size. Don’t choose a sample rate higher than the rate used to store the music originally or you’ll waste space. CD quality, for example, is 44.100 kHz, so choosing a higher rate when you’re encoding from a CD is unnecessary. In general, the best choice is Auto, which uses the same rate as the original music.
Sample Size: The number of bits used to store each sample taken as the music is encoded. The higher the sample size, the better the quality and the larger the file size.
Channels: If you don’t have stereo speakers or if your audio files are monaural (mono files are about half the size of stereo files), choose Mono. If you’ll be listening through headphones or a stereo system, choose Stereo or Auto. Auto converts monaural tracks into mono files and stereo tracks into stereo files.