When you import songs into iTunes from CDs, the default encoding format is AAC (Advanced Audio Coding).
You can change the encoding format and other settings that iTunes uses to import songs. Your choices affect the audio quality and size of the song file (the higher the quality, the larger the file size). Songs you import into iTunes are stored on your computer’s hard disk.
You can use custom settings for greater control over the quality and size of imported files.
iTunes supports HE-ACC files (also called MPEG-4 AAC files), not older versions of AAC. HE-AAC encoding is available only if you have QuickTime7.6.4 or later installed.
To choose import options:
Choose iTunes > Preferences, click General, and click Import Settings.
Choose an encoder from the Import Using pop-up menu.
You can listen to songs encoded in AAC or Apple Lossless formats in iTunes, on iPhone and iPad, and on iPod models that come with a dock connector. If you plan to listen to your music using a different program or MP3 player, choose MP3 Encoder.
If you want to burn high-quality audio CDs with the songs you’re importing without losing quality, choose Apple Lossless or AIFF. (Keep in mind that songs imported using this format use much more disc space.)
If you’ll be playing your songs on a computer that does not have MP3 software, choose WAV.
Choose a bit rate from the Setting pop-up menu (not available with Apple Lossless Encoder). In most cases, the default selection works well.
If you chose MP3 Encoder, choose one of the following from the Setting menu:
Good Quality: Use to fit more songs on a portable MP3 player with limited storage capacity.
High Quality: Choose if you play music in a noisy environment. This setting creates files that are about 1 MB in size per minute of music.
Higher Quality: Choose if you plan to create your own audio CDs or listen to your music with high-quality stereo speakers.
Custom: Choose for greater control over the file size and sound quality.
To use custom settings with MP3 encoding:
Choose iTunes > Preferences, click General, and click Import Settings.
Choose MP3 Encoder from the Import Using pop-up menu.
Choose Custom from the Setting pop-up menu.
Choose settings from the following menus:
Stereo Bit Rate
Variable Bit Rate Encoding (VBR)
Sample Rate
Channels
Stereo Mode
These settings are explained below in “What you can adjust using the encoding settings menus.”
To have iTunes analyze your encoding settings and music source, select Smart Encoding Adjustments.
Select or deselect Filter Frequencies Below 10 Hz.
Filtering inaudible frequencies results in smaller, more efficient files without perceptible loss of quality.
To use custom settings with AIFF or WAV encoding:
Choose iTunes > 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.
Choose settings in the Sample Rate, Sample Size, and Channels menus.
These settings are explained below in “What you can adjust using the encoding settings menus.”
To use custom settings with AAC encoding:
Choose iTunes > Preferences, click General, and click Import Settings.
Choose AAC Encoder from the Import Using pop-up menu.
Choose Custom from the Setting pop-up menu.
Choose settings from the Stereo Bit Rate, Sample Rate, and Channels menus.
These settings are explained below in “What you can adjust using the encoding settings menus.”
What you can adjust using the encoding settings menus:
The encoding settings are available only if you choose Custom from the Setting pop-up menu. Here’s a brief explanation of the music properties you can change:
Stereo Bit Rate: The higher the Mono or Stereo kilobits per second (kbps), the higher the audio quality and the larger the file size. The most common bit rate for stereo MP3 files is between 128 kbps and 192 kbps. Lower bit rates are more appropriate for sound files containing voice recordings (as opposed to music).
Variable Bit Rate Encoding (VBR): This setting varies the number of bits used to store the music depending on the complexity of the music. This can help keep file size to a minimum.
Sample Rate: The number of times per second that 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 originally to store the music 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.
Stereo Mode: In Normal mode, your MP3 files contain one track for the right stereo channel and one track for the left. In many cases, the two channels contain related information. In Joint Stereo mode, one channel carries the information that’s identical on both channels, and the other channel carries the unique information. At bit rates of 160 kbps and below, this can improve the sound quality of your converted audio.
To change the default location of imported files:
Choose iTunes > Preferences, and click Advanced.
Click Change and select a new location for your files.
From now on, new songs and other items you import will be stored in the new location. Songs you’ve already imported stay in their current location.
To restore the iTunes folder as the default storage location, choose iTunes > Preferences, click Advanced, and click Reset.