The driver unit is the component that produces sound in the device. Bigger drivers are more powerful and can produce better bass.
Audeze LCD2 Classic: 106mm
16. has active noise canceling/noise reduction
This type of device allows you to listen at lower volume levels, causing less ear fatigue as you don't have to crank up the volume to overcome background noise. Ideal for plane rides and morning commutes.
13% have it
17. travel bag is included
The device comes with its own special case or pouch, which is useful for safe transportation.
63% have it
18. has a straight plug
A straight plug is better when the jack is on the top or bottom of your player.
50% have it
19. has included ear pads
Allows you to change ear pads without buying new ones.
42% have it
20. has an L-shaped plug
An L-shaped plug is better if the jack is on the left or right side of the device, so that the cable isn't bent, and is less likely to break when the device is in your pocket.
31% have it
21. has a battery level indicator
An indicator shows you when the device has low battery.
12% have it
22. has a 3.5mm male connector
A standard 3.5mm male connector is suitable for use with all MP3 players and computer sound cards.
83% have it
23. number of microphones
More microphones result in better sound quality and enable the device to filter out background noise.
Parrot Zik Sport: 8
24. cable length
A long cable ensures more freedom of movement.
Pioneer SE-A1000: 6m
25. has an on-ear form
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.