An amplifier is integrated into the device. An audio amplifier takes a small signal and makes it bigger without making any other changes in it which results in better sound, so any sound source can be connected to speakers.
61% have it
8. has an AUX input
An auxiliary input allows you to play other audio sources by connecting them through a simple audio connection like a 3.5mm jack, i.e for MP3 or portable DVD/CD player.
84% have it
9. drivers count
A speaker driver is an individual transducer that converts electrical energy to sound waves. More drivers may result in better sound quality.
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.