Eli5: why do wired headphones that plug into your phone never need to be charged but wireless ones do?

Question

I thought maybe they got power from the phone but then I remembered old headphones plugged into a phone jack separate from the charging port so how come one type never needs to be charged and one does?

In: 0

Answer 1

Wired headphones to a cellphone, (like wired speakers to a stereo player) get the electric signal from the cable in an analog way, it contains both the energy and the signal.

That is enough to move the magnet&membranes in the speaker and reproduce the sound.

But for wireless speakers, the wireless signal does not transfert [enough] energy. And the headphone needs a source of electric power to : run the Bluetooth receiver/sender, and move the membrane to produce the sound.

[Edited to add remark]