Design and features:These earphones work with or without the noise canceling feature being turned on. You can use the noise-canceling feature without listening to music, but the audio cable can't be detached to get it out of the way when the headphones are being used for noise reduction only. The earphones have medium high sensitivity when the noise cancelation feature is turned on so they can provide satisfying volume levels when used with home audio equipment and lower powered portable audio devices. When the noise cancelation feature is turned off they have medium sensitivity; so they can provide satisfying volume levels when used with home audio equipment and all but the lowest powered portable audio devices. The QuietComfort 20 comes in two version - both have an in-line remote control with an built-in microphone, volume controls, and player function/call connect/disconnect control. The iOS version has controls that work with Apple mobile devices; the Samsung version has controls that work with Samsung Galaxy mobile devices and many other Android mobile devices. These earphones may not operate properly with some non-Apple/non-Android mobile devices or other audio equipment. Additional features include a monitor function so that you can hear ambient sounds while in noise canceling mode while still wearing the earphones, and support for voice control when used with devices that have that feature. Both versions come with three pairs of ear bowl support earpieces of various sizes, a USB charging cable, a shirt clip, and a carrying case.
Sound quality: We found the QuietComfort 20 provides Excellent active noise reduction, and when the noise cancelling feature is used it delivers sound quality that falls in the Very Good range - it reproduces music and voice very well although it does have some noticeable sonic quirks. The overall sound can be summarized as bass-heavy. Bass (as in bass drums, bass guitars, stand-up bass, etc.) has good impact but is prominent and thumpy. The midrange (voices, guitars, horns, etc.) is even but a bit grainy. The treble (cymbals, the upper range of violins, etc.) is somewhat subdued and upper treble is muted. This model does a decent job of recovering the room ambience of a recording (the sense of the acoustic space in which the audio program that's being listened to was recorded) and the sound has a good sense of liveliness, but it is somewhat closed-in (sound-wise it's fairly obvious you have something plugging your ears). When the noise cancelling feature is turned off the sound becomes thinner, more grainy, and less bassy and the sound quality falls to the Good range. These headphones provide Excellent noise reduction across the entire frequency range with the low frequencies reduced the most. Faint hiss is heard when there is no ambient noise to drown it out, orientation slightly changes the noise reduction characteristic - when the noise is coming from the back slightly more low frequency noise can be heard. We found that this model is susceptible to hum when used in the noise canceling mode with, or near, some AC powered audio equipment.
Comfort: The QuietComfort 20 is a hybrid ear insert/ear bud design - the earpieces seal the ear canals but they don't insert into the ear canals as far as typical ear insert models, and they are supported by ear bowls like a ear bud model rather than the ear canals. They fit and stay in place with no problem and the ear bowl support ear pieces are very stable even with vigorous head movement; however, the battery/sound module that is integrated into the cable needs to be supported, otherwise it pulls on the earphones. The sound of the earphone audio cable rubbing on clothing may be transmitted by the earphones.
