Subwoofer Hum (1 Viewer)

[PatLN]

I have an Onkyo HT-R520 Receiver with a 1000 watt 6.1 HT. I have had it for a couple months now, and i have started noticing that the input from my laptop creates a fairly loud hum. I have tried switching inputs on the back of the receiver, they are all the same. However, my xbox and DVD player do not create any hum. I am not sure if this helps but my ipod doesnt create any hum when using the same headphone -> RCA adapter when plugged in. But it does create a hum when it is attached to the dock which is attached to the computer. It seems like when there is power applied a hum is created. However i was using the same headphone to rca adapter for months without a problem. I made sure that the laptop and receiver/sub werent on the same power strip. I am really confused as to what is causing this annoying hum. Any ideas would be greatly appreciated.

 

[Jim Mcc]

All your connections have me confused, but when my sub started humming a while back, it turned out to be a bad sub. cable. I just used RG6 cable for my new sub. cable.

 

[JeremyErwin]

Most likely a ground loop problem. You'll want to plug all of your equipment into the same power strip, use optical spdif instead of rcas., or insert isolation transformers at appropriate points, though this may color your sound.

I'm of the opinion that mini jacks are evil. Had to deal with too many dodgy connections, I suppose.

 

[John S]

It may help attempting to find out why it does it. Laptop audio is often badly compromised by the manufacturers.

 

[Gabriel.H]

I have the same problem hooking a stereo line-out cable from my pc's sound card to my receiver. It's not just laptops or ipods.

 

[JeremyErwin]

Question:

Is the laptop plugged in, or is it running off batteries?