For those who may not be headphone tech geeks, deciding on a high-end pair to purchase can sometimes be daunting. The technical terms and marketing language that often accompany with headphone descriptions is enough to make your head spin. With that in mind, this post aims to simplify the terminology associated with the two main types of “over-ear” headphones: closed-back and open-back. Though many audiophiles argue for one side or the other, neither type is a clear cut winner—they each have their pros and cons.
The more common of the two, closed-back headphones are arguably more practical as well. They make up the majority of over-ear headphones that you’ll run into, and while they may come in a variety of shapes and colors, the core structure remains largely the same.
“Closed-back” refers to the type of ear cup on the headphones, and in this case, the ear cup is sealed. Due to the sealed ear cup, closed-back headphones isolate sound very well, and most seal around the ear well enough to produce around a 10 dB (decibel) attenuation of exterior noise. These headphones are ideal for listening in noisy environments, such as on airplanes or on the subway during morning commutes. Many higher-end models also offer noise cancelling technology to go along with the already capable noise isolation.
The design of closed-back headphones promotes keeping noise outside the headphones, and at the same time, they also seal your own music inside the headphones. In most cases, unless the playback volume is exceedingly loud, those around you will not be able to hear your music—even in a quiet setting. This is ideal for listening at a library, in a car, or wherever you’d like to keep your listening private.
However, the closed design that provides many benefits also provides some trade-offs as well. Sound is often more immediate and intense because of the sealed ear cups, but sometimes sound can feel compressed because it cannot escape the cup and instead reflects back into the ear. The closed cup also affects tonal distribution. In comparison to the high frequency sound waves, the bass frequencies with longer wavelengths do not lose the same amount of energy when reflecting in the closed cup, causing closed-back headphones to often be bass heavy. This isn’t necessarily a bad thing, and many enjoy a slight bass boost when listening to music.
A common difference with closed-back headphones are mostly in regard to the soundstage—the overall “width” and “depth” of the listening experience. Closed-back headphones typically do not provide the same expansiveness and crispness as open-back headphones, and are often more acoustically constrained because sound waves are unable to move freely out of the ear cup. As far as the tonality difference, closed-back headphones normally have a darker tone, whereas open-back headphones generally sound brighter. Noise isolation and tonal immediacy are second to none in closed-back headphones, but it is difficult for the headphone design to mimic the soundstage offered in open-backs. However, some modern headphones such as the OSSIC X utilize acoustic foam in the ear cup chamber to mitigate reflections, therefore allowing sound waves to dissipate in a more natural manner, minimizing the constraining quality that occasionally affects closed-back headphones.
The open-back style is less popular than closed-back overall, but many audiophiles swear by them because of the unique sonic experience they can provide. Open-back headphones are often easily identifiable due to the use of mesh or other perforated material on the back side of the ear cups, allowing the sound from the outside world to enter the headphone.
Sound accuracy and vibrancy punctuates the listening experience of open-back headphones. The somewhat impractical nature of the design can be a deterrent to some, but the listening experience is well worth the drawbacks, as long as a reasonably quiet environment is available for use. The open ear cups allow sound to escape freely, and because there are no reflections or restrictions, the soundstage is able to feel open, airy, and lively, almost similar to listening at an amphitheater or through high quality, well-placed speakers.
In contrast to closed-back headphones, because of the open cup design, open-back headphones provide almost no sound isolation at all. Any noise coming from outside the headphones will be at essentially normal volume, which can be a good thing if hearing sound from the surrounding area is a desirable feature, such as for a runner who would like to stay alert while navigating busy streets. However, because open-back headphones do not isolate noise, playback volume must be increased to offset this, except in quiet areas. This style is also less useful on airplanes and in other noisy environments. The tonality in open-back headphones is often more midrange-focused, giving them a warm, crisp sound, but they can sometimes be light on bass.
As the open ear cup does not seal much noise out, and it isn’t able to seal sound in either. Open-back headphones are prone to leak sound, and playback can be heard by anyone in the immediate area. If you typically listen in an environment where disturbing others could be a concern, open-back headphones may not be the best option. In the same vein, the open ear cups do not provide much privacy for the listener either, and those around you may be able to listen in on your music.
Closed-back headphones have the edge in noise isolation, practicality, and bass frequency boost, and open-back headphones provide remarkable depth and auditory engagement, and produce a more organic overall sound. Both have their advantages and disadvantages, and choosing between the two designs comes down to personal preference.
Our own OSSIC X is a closed-back headphone, offering versatility and practicality, but also includes multi-driver 3D audio, automated anatomy calibration, and real-time head tracking to provide the most immersive experience that headphones can provide.
Here's a video from our team describing the features of the latest OSSIC X prototype: