Subwoofer rumble when my PC is on? Advice needed.

[mickrick]

Okay, this is a strange one. I'm getting a rumbling sound from my home cinema subwoofer when my pc is on. It sounds like a van or motorcycle is sitting idling outside my house. But the really strange thing about it is, it only happens when my either hard drives, or rather, ssds, are under stress (when the hard drive led is flickering), such as opening an application or running a game, or when I move the mouse.

My pc is made up of an Asus ROG Maximus VIII Gene board, i7-6700K, 24gb ram, 256gb Samsung m.2 ssd (system), Sandisk 480gb (games install) and OCZ 240gb (system backup) SSD's, and a geforce 750-ti graphics card. Graphics are taken from hdmi1 on the 750-ti to my 4K tv, and sound is taken from hdmi2 to my home cinema receiver. The subwoofer is on its own power socket, away from the rest of my equipment, to eliminate ground hum. I've tried other hdmi cables but the problem is still there. There is no such sound from any of the other speakers.

Any ideas what could be causing this?

 

[Curlev]

Maybe it could be a ground-loop hum? Have you tried to connect the subwoofer to the same wall socket as the other parts?

 

[aquielisunari]

Maybe it could be a ground-loop hum? Have you tried to connect the subwoofer to the same wall socket as the other parts?

https://electronics.howstuffworks.com/how-to-stop-subwoofer-hum.htm offers an explanation of that possibility and some steps that may resolve it. .

 

[Curlev]

Maybe it could be a ground-loop hum? Have you tried to connect the subwoofer to the same wall socket as the other parts?

https://electronics.howstuffworks.com/how-to-stop-subwoofer-hum.htm offers an explanation of that possibility and some steps that may resolve it. .

Great info!

 

[JamesSneed]

Have you tested disconnecting your HDMI to the TV and receiver separately to see if it goes away? Just curious if its coming over the one of the HDMI lines or power line.

 

[mickrick]

Thanks for the replies guys. I had a good look at it last night. I disconnected both of the hdmi cables at once, and the sound was still there. Then I had a look at the graphics card and saw my wifi/bluetooth card was in the adjacent slot to the graphics card and moving this to the furthest slot away seemed to lessen the noise considerably, but it later came back again just as bad as before. I don't think its a ground loop hum as it disappears when the pc is turned off, but still connected to the mains. A ground loop hum is still there as long as the offending appliance is still plugged in.I'm thinking a grounding issue with the psu/motherboard. Maybe the power connector. I'll have to try another psu tomorrow to rule it out.