Strange sound from computer speakers...

[Giddora]

Okay... This is going to be very hard to explain, but I'll try my best.

Setup:
One Lumia 920. One desktop-computer with a wired computer and wired external speakers. 2.1 soundsystem with two speakers on the desktop and a subwoofer on the floor.

My subwoofer does some strange things relatively often. It sometimes sounds like there's a russian radio-guy talking and then he fades out. So I'm quite used to strange sounds from my speakers... But this latest revelation really blew my mind.

I got an sms on my cellphone, so I picked it up and answered the message and put it down without turning off the screen. Without noticing it, I had put the cellphone ontop of my keyboard cable running to my desktop computers USB-connection on the front.

All of a sudden, my subwoofer started making a ticking sound. (About 4 ticks per second)

I looked down on my phone and noticed how the ticking sound went away when the display shut off from it's 30 second timeout.

I picked up my phone and lit the display, and once my phones camera gets close to the cable, the subwoofer starts making a very audible tick again. It's the same tempo the entire time.

Does this have something to do with the QI-wireless charging thing? Because it only happens when I put the area of the camera close to my keyboard cable. It doesn't happen on my audio-cable to any of the speakers or the mouse-cable or the powercables or the HDMI-cable or the network cable. Only the keyboard cable.

 

[warrentaye]

Its normal, just keep the phone away from ur speakers.

 

[Scott Maier]

Generally, it is a GSM phone issue. Here is a page that explains it if interested: Weird & Wireless: Why do mobile phones cause noise on my office speaker phone? (Electro-ramblings)

 

[Giddora]

But why don't it affect the speakers when I put the phone close to the speakers? And why only when the cellphone-display is lit?