This device comfortably rests on top of your outer ears. As it doesn't block out everything from the outside world, it's preferred in places like office environments and recommended for outdoor activities.
Bowers & Wilkins P3
22% have it
17. diaphragm size
The diaphragm moves air back and forth to create sound. The bigger the diaphragm, the more bass it can produce.
Oppo PM-1: 85mm
18. has an open-back design
The device is designed in a way that allows sound to go out through the back of the ear cups, which usually have vents or perforations. This design provides very natural and accurate sound.