old speakers

[jokers_show]

i have got 25 years old birco speakers , they are around 2 feet in length .

i tried those speakers with my sony music system and that are working fine .
i would like to know, how could i know that speakers have amplifier in them?

 

[Brajendu]

There will be a knob somewhere to turn clock-anti clock wise, and it changes the volume if you operate it.hyeah: