Computer speakers were not made to produce concert-quality sound, but you can optimize your computer's sound quality for the types of music you like with this cost-free adjustment.
The acronym "EQ" stands for equalizer -- a series of adjustments that allow you to fine-tune individual sound frequency ranges. Think of an EQ as a detailed way to adjust volume: Rather than increasing or decreasing the total sound coming out of your speakers, you can adjust certain sounds -- such as the low, thumping bass -- to be louder in the total sonic mix.
Open iTunes and select "equalizer" from the "view" menu on the toolbar. You'll see a window featuring a row of sliders: Each slider controls a different frequency, from low to high, in the overall sound mix. A drop-down menu above the sliders lets you use preset mixes for various music genres. Play a few songs with these presets, and notice how the sound quality changes -- do the high tones gain more "sparkle"? Do the low bass frequencies have more "thump"? Note how these changes relate to the settings on the EQ [source: Tozzoli].
There's no perfect EQ setting for iTunes since every song is different, and every computer's speakers will project sound in a different manner. But a basic understanding of EQ settings will go a long way to helping you make your favorite songs sound as bright, punchy or powerful as possible on your computer's speakers.