EQuation: MP3 players with great sound-enhancement features

If music is food for you ear, EQ is the spice that can make bland music more palatable, or spoil a perfectly good song. From a practical standpoint, audio equalization (EQ) is meant to compensate against all the real-world factors working against an ideal listening experience (i.e. cheap earbuds, background noise, small speakers). If the handful of EQ presets on your iPod aren't enough to get the job done, however, the following MP3 players offer a virtual buffet of sound-enhancement options. Each one of these portable audio players include a custom 5-band EQ, dedicated bass-boost controls, settings that restore high-frequency detail, 3-D surround effects, and more.

The Sony Walkman NWZ-S718F (an Editors' Choice) is a notable new addition to this list because it includes an integrated noise-cancellation feature along with Sony's expected assortment of top-tier EQ settings. Another newcomer to our EQ roundup is the Creative Zen X-Fi, which boasts a sophisticated general-purpose audio sweetener dubbed the X-Fi Crystalizer.

For those with moderate to severe hearing loss who depend on EQ to compensate for frequencies they have trouble hearing, the Cowon iAudio 7 offers a powerful built-in headphone amp, a 5-band EQ with definable frequency ranges for each band, and panning controls to compensate for unilateral hearing loss.