How can speakers pick up radio signals?

Question

Some of the speakers I have pick up radio frequencies and I can faintly hear the music.
Same thing happens for the signal my cellphone receives before receiving a call or a text message.

Speakers only do this when they're turned on, and they work by using electromagnetism to cause vibrations in the air. Which means that the radio waves from my cellphone (or whichever waves they use) cause the electromagnet to turn on, meaning an electric current is going through the spool. So, my question actually is: how can radio waves induce an electric current?

(Probably something to do with the fact that radio waves are electromagnetic waves, but I don't know, that's what I'm hoping to find out :D)

And please, intelligent answers only. saying "Your speakers pick up radio signals" doesn't answer any of my question. Thank you

Answer 1

It's not the speakers that pick up the radio signals, it's the electronics that the speaker is attached to that pick up the signals. Speakers don't turn on or off, again, the electronics that drive the speaker turn off and on.



Radio signals are electromagnetic signals, as you know. Any EM signal that hits any wire will induce a voltage in that wire, although it's usually a very small voltage, in the microvolt range, although under some conditions it can be much stronger. That is why much electronic equipment is in metal containers to shield against these signals. For example, a wire running next to an AC power line can have volts of signal induced into it.



How the speaker gets the sound is complicated. The wires from the speaker to the amplifier or whatever is driving it tend to be long, and you can get voltages from AM radio stations picked up. These RF signals can travel back into the amplifier via feedback connections, and appear at the input to the amplifiers. There, any non-linearities in the amp can cause the RF to be rectified, and therefore demodulated, and the audio signal can be seen. This can be, in turn, amplified by the amplifier and sent to the speaker.



.

Answer 2

Speakers Picking Up Radio

Answer 3

The speaker wires are performing as antennas. try shortening them as much as attainable, coiling any extra into tight coils. you're able to upload Ferrite chokes on the speaker ends (attainable at Radio Shack). in case you are able to no longer discover the chokes, try wrapping countless turns of the speaker twine around a extensive nail or bolt. Use of shielded twine for the speaker wires would help additionally. If it in uncomplicated terms occurs while the Amplifier linked to the audio device is became on, then something linked to that amplifier could be performing as an antenna. same advise for those wires to boot because of the fact the AC potential twine. Get interior the habit of turning the Amp off while no longer playing issues.