For headphones, I appreciate Skullcandy. (Don’t laugh!) They may look ridiculous and seem like a sugary brand, but even the earphones produce Bose quality sound at a more affordable price. Personally I own a pair of FMJ’s which produce a range from 16–20,000Hz, which probably includes more frequencies than I can hear, but makes me feel good inside. The cushions around the earbud speakers (you’re given three sizes with the better sets) makes an excellent seal, providing the same experience as low-level noise canceling headphones/earphones. Bose, while expensive, is excellent for external speakers. I’ll be of no help regarding sound cards though. It is true. The range is most preferable because it covers the entire (general) range of human hearing. Some individuals can perceive frequencies as low as 12Hz, but this is relatively uncommon and thus “overkill” in terms of sound equipment. The range is also important for full bodied sound. Most systems are incapable of producing the freqquencies on the lowest end of the spectrum, which leads to hollow, shallow sounding music.