When searching for a new pair of on-ear or over-ear headphones, one important step to making the best selection is to consider all the headphone types available. A functioning knowledge of headphone type, also known as acoustical principles, allows buyers to make a selection that best satisfies their expectations as listeners while meeting the demand of a headphone’s intended use. The three main acoustical principles found in modern headphones are closed-back, open-back, and semi-open back designs. Each principle offers users a unique and markedly distinct experience suited for particular environments and applications.
Perhaps the most ubiquitous acoustical principle, one of the primary advantages of closed-back headphones is minimized sound leakage. Whether in an on-ear or over-ear design, the closed-back headphone prevents music from spilling into your surroundings and keeps ambient noise from penetrating the reproduction. The resulting effect is described as sound isolation and is defined by a reproduction that is minimally colored by ambient noise.
Because they are among the best suited for quality reproduction even in noisy environments, it is of little surprise that sealed headphones are among the most common. Closed-back headphones are particularly well suited for studio engineers and DJs who demand a focused sound despite loud surroundings and are also of great benefit for travelers and office use.
Of course, for all the benefits of being able to listen to high quality audio in raucous environments there are some trade-offs. Most notably, the acoustic character of sealed headphones can have a constricted quality with a compressed sound stage leading to less resonant high and mid frequencies. Nonetheless, the limited space of the chamber does have some advantages particularly for enthusiasts of lower frequencies and robust bass. For such individuals, closed-back headphones may provide the most satisfying experience.
Open-back headphones are the inverse of closed-back headphones. Unlike sealed headphones, open-back headphones allow sound to flow freely through the drivers allowing more sound to emanate from the headphones. The effect of this acoustical principle is to achieve a broadened sound stage with organic and realistic sound character. While bass frequencies are not particularly accentuated, they tend to be properly balanced with higher frequencies which are allowed to ring and develop over time and space because of the free flow of air through and around the transducers. To many listeners, the freedom and natural development of the sound waves offers the highest quality sound.
While the convincing realism of the open-back sound stage can be impressive, it practically relegates the open-back headphone to the private and silent rooms of a home. Not only might people nearby find the sound leakage of the open-back headphone distracting, open-back headphones also allow ambient noise into the transducer resulting in sound so tainted by noise that it is hardly enjoyable.
Certainly one of the most polemic principles available, semi-open back headphones attempt to reconcile the opposing acoustical principles by blending certain qualities of each. The semi-open headphone offers some sound isolation without fully enclosing the chamber and allowing sound to develop organically. While this certainly creates a more dynamic sound character, semi-open headphones might still leak enough sound to be a nuisance to others and should be considered as open headphones with better isolation.
In other words, semi-open headphones are more than likely to be a better fit for private listening than something one might use in a quiet library or office.
Conclusion: Choosing Yours
Knowing the distinct characteristics of each acoustic principle, it is time to think about what your demands are from your headphones. When choosing, be sure to consider the environments you are most likely to be in while enjoying your headphones.
If you know that you will be in busy and loud environments, DJ-ing the next block party, or monitoring a live performance, no other type of headphone will better serve your purposes than a fully closed, enclosed ear design. On the other hand, if you wan to unwind after a long day at work to the immaculate sound of your headphones in the privacy and quiet of your favorite lazy chair, open-back headphones might be the perfect companions (as I know they are for me!).
Most importantly, the acoustic principle of a pair of headphones is meant to help you get the most out of your music. Be sure to consider the types of music you are most likely to listen to. For instance, if you prefer classical or acoustic performances with balanced and rich sound textures, perhaps a semi-open or open design will be your best fit; whereas if you are into electronic and bass heavy music, a closed principle may better reflect the robust bass frequencies you are seeking.