[SOLVED] Radio Playing through my speakers all the time.

rsteinmetz70112

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I have a desktop computer with Windows 10. Recently a radio station began playing through my speakers at low volume all the time. I thought it might be the speakers so I changed them out. It got worse, but at least now I can hear the music better. It is a local radio station.

The motherboard is Asrock N68C-GS4 FX with 5.1 CH HD Audio (Realtek ALC662 / VIA® VT1705 Audio Codec)

How can I make it stop?
 
Solution
The speaker and input wires are acting like antennas and the amplifier circuitry ends up demodulating the minute differences between wires into audible signals. Shielding the speakers or the amplifier itself probably won't make any difference, the inputs and outputs need chokes to reject EMI because the amplier does not have adequate filtering.

I had a similar problem with my amplifier picking up GSM noise which I fixed it by running a #16 ground wire from my amplifier's grounding lug to my PC's case and running the audio cable alongside that. Grounding solely by the 3.5mm jack simply isn't enough in some cases.
The first thing that comes to mind is...
Is the case grounded?
Do you know how to check to see if it is?
If not...try another outlet somewhere else in the house....preferably far away from the one you are using. Maybe your outlet isn't grounded.....or it lost it's ground.
 

rsteinmetz70112

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Thanks The computer is in my office in a high rise building.

I have found the location of the speakers makes a difference in the volume and unplugging them from the computer or disconnecting the power from the speakers stops the sound.
Adjusting the speaker volume either in Windows on on the Speakers apparent has no effect.

I'll get my polarity tester out and check, I need to bring it in from home. I'm pretty sure the outlet and case are grounded.

I'm wondering if something is running in the background streaming the radio.
 
If you unplug the signal wire (the wire that goes from the PC to the speakers) and leave the speakers powered....and the sound stops....the sound is coming from the PC.

Although I think it's really weird that adjusting the volume on the speakers themselves would have no effect in this case. So....if you adjust the volume on the speakers all the way down.....you still hear it?
 
When you say Radio you are hearing an actual radio station?
Cover with Aluminum foil to shield EMI, do each device to see if it can be isolated to 1. (L,R,power)
Amplifier may have a circuit tuned to that station.
Could someone it the building be using the wiring to send music to a remote room.
 

rsteinmetz70112

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Thanks [B]MJS WARLORD[/B], I'll check some of the suggestions there when I can put my hands on the computer.


When you say Radio you are hearing an actual radio station?
Yess I am now clearly hearing WWOZ radio.
Cover with Aluminum foil to shield EMI, do each device to see if it can be isolated to 1. (L,R,power)
Amplifier may have a circuit tuned to that station.
Could someone it the building be using the wiring to send music to a remote room.
I'm away from the site now but when I get back I'll try shielding the whole thing. I changed the speakers, it got worse, I change out the webcam with not change.
I still need to check the grounding, but I'm pretty sure it's grounded.
 

rsteinmetz70112

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Finally got back. Grounding is fine. The case and the outlet both show grounded.
I've eliminated the OS by starting a Linux live session with the music still playing.
I tried disabling the onboard sound with no effect.
I've ordered a new PCI sound card, I'll try switching to that and see if it makes any difference.
I haven't had time to try wrapping the whole thing in tin foil.
 

InvalidError

Titan
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The speaker and input wires are acting like antennas and the amplifier circuitry ends up demodulating the minute differences between wires into audible signals. Shielding the speakers or the amplifier itself probably won't make any difference, the inputs and outputs need chokes to reject EMI because the amplier does not have adequate filtering.

I had a similar problem with my amplifier picking up GSM noise which I fixed it by running a #16 ground wire from my amplifier's grounding lug to my PC's case and running the audio cable alongside that. Grounding solely by the 3.5mm jack simply isn't enough in some cases.
 
Solution

rsteinmetz70112

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The second set of speakers are an ancient pair of Yamaha Speakers. I have several but have never experienced this before.
I tried putting chokes on the cables, it turns out I had some in my junk box. That stopped the radio on the unpowered speaker, but the powered speaker kept playing the radio. Apparently the amplifier was picking up the radio. I tried yet another set of old speakers and that seems to have done the trick. I can now listen to music when I want a participate in zoom meetings without background music.

Thanks everyone for your help.