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Setting iTunes Import Preferences > Choose an Encoding Quality Level - Pg. 38

iTunes: Burning Down the House 38 Although the default MP3 encoding settings are probably fine, you might want to experiment with the MP3 encoding settings to get the smallest file size possible while retaining an acceptable quality of playback. Understanding MP3 Encoding The quality of encoded music is determined by the amount of data that is stored in the MP3 file per second of music playback. This is measured in KiloBits Per Second or kbps. The higher the number of kbps, the better the music will sound. Of course, this means that the file size is larger as well. The goal of MP3 encoding is to obtain an acceptable quality of playback while minimizing the size of the resulting MP3 files. The encoding level that you should use depends on several factors, which include the following: · Your sensitivity to imperfections. If you dislike even minor imperfections in music playback, you should use higher quality encoding settings. If you don't mind the occasional "bump" in the flow of the music, you can probably get away with lower quality settings. · The music to which you listen. Some music hides "flaws" better than others. For example, you are less likely to notice subtle problems in the music while listening to grinding heavy metal music than when you listen to classical music. · How you listen to music. If you use a low-quality sound system with poor speakers, you probably won't notice any difference between highquality and low-quality encoding. If your Mac is con- nected to a highfidelity sound system, the differences in music quality will be more noticeable. · How important file size is. If you are going to be listening to music on an MP3 player, you might be willing to trade off some quality to be able to fit more music on the player. If you are mostly storing music on a hard drive, you can choose higher quality because file size won't be as important. There are three standard levels of MP3 encoding that iTunes provides: Good, Better, and High. As an experiment, I encoded the same 4-minute song using each of these levels; the results are shown in Table 2.5. These results might or might not match the particular encoding that you do, but they should give you some idea of the effect of quality level settings on file sizes. In this experiment, I couldn't detect much difference between the quality levels on the sound of the music, so I could save almost 0.5MB per minute of music by sticking with the Good quality level. Table 2.5. Default Encoding Quality Settings Versus File Size Quality Level Good Better High Data Rate (kbps) 128 160 192 File Size (MB) 3.8 4.8 5.7 If none of the three standard levels of MP3 coding is acceptable, you can also create custom en- coding levels. Configuring Standard Levels of MP3 Encoding To configure iTunes to use one of the standard levels of MP3 encoding, use the following steps. Choose an Encoding Quality Level 1. 2. Open the iTunes Preferences dialog and click the Importing tab. On the Import Using pop-up menu, choose MP3 Encoder (it is selected by default).