The Klipsch Custom 3 earphones bill themselves as a "Studio Reference Experience," however, we found that they leaned too hard on the low end to be useful as a balanced pro-audio reference. We may not recommend the Custom 3s to audio engineers, but that shouldn't stop the rest of you from seeking them out, especially if you like your music on the heavy side. We really enjoyed using the Custom 3s for watching movies on our laptop, where the extra oomph of the headphones' dedicated woofer driver made blockbuster sound effects knock us out of our seat.
Some tunes suffered for the Klipsch Custom 3s' bass-heavy sound. For instance, the upright bass on Johnny Cash's Folsom Prison rendition of "Cocaine Blues" crowds outs many of the subtleties of the live room. Other songs, such as Moondog's relatively sparse "Bird's Lament" and Screamin' Jay Hawkins' "I Put a Spell On You" really come alive with the extra heft of the Custom 3s' powerful woofer. Hip-hop and electronic tunes such as Prefuse 73's "Uprock and Invigorate" also sound phenomenal. Those of you looking for a more balanced set of Klipsch earphones should consider the less-expensive Custom 2s or Image X5s.
As far as fit and comfort are concerned, we feel the wide range of ear tips and the memory wire's capability to distribute weight across the ear make the Klipsch Custom 3s easy to wear for long stretches without discomfort. Compared with the invisible-feeling Image X5 earphones, however, the Custom series makes much more contact with the ear, which may irritate some users.
The Klipsch Customs come with a two-year limited warranty against defects, although it remains to be seen whether the company's policy is as forgiving Shure's.