Background Noise from Computer Speakers
 

Anyone knows how to eliminate this?

Whenever my computer's speaker is turned on, there are quite a bit of static hum and background noise coming out of it. Not apparent when I am playing music or if the TV is on, but you can really hear it when it is quiet.

Weird thing is, the background noise is gone (or significantly less) if I unplug the speaker from the computer (which kinda suggest the noise is coming out of the computer instead of the speaker itself?)
However, I will still get the background noise when my computer is turned off as long the as speaker cable is connected to he computer.

Any audio guys know why is that and how to fix that?

Turn down the speakers, turn up the volume on the computer.

I hear the same thing when I plug my laptop into the LCD TV and have the volume up. I believe it's electrical interference. Depending on what the source of the interference is, using a shielded cable may help.

If you're using on-board sound it's the interference generated by the computer's pieces that use significant power. Fans are terrible at creating this (even though they use not much power), along with other sources, because they use a magnet to turn the blades and if the fan isn't shielded properly it creates a buzzing sound.

Best way to take care of it is to buy a cheap soundcard and get your sound chip away from the motherboard.

Actually..there are two noises coming from the speakers, one is more like a mechanical hum which disappear as soon as I disconnect the cable, and the level of "humming noise" is unaffected by how low or high I turn the speaker. It appears as soon as I turn on the power of the speakers.

The other noise is morel like a "hiss" which get louder as I turn the volume higher.
The hiss is barely audible and doesn't annoy me. (unless i turn the volume all the way up which I don't)

It is the low frequency hum that's annoying me a lot...

The "hum" is probably from a ground loop, caused by the two systems having multiple paths to a common ground. It could also be from a cheap speaker power supply that doesn't filter its power well.

The hiss is just inherent in all audio electronics; it will be worse with cheaper components. It's just low-level background noise.

Depending on the speakers, you might try a different power supply... or you might find a way of grounding the speakers. Make sure the computer is plugged into a properly grounded outlet as well.

i found that if you're using a soundcard on the motherboard - you'd sometimes get static when you move the mouse around. turns out that the case speaker was picking up interference and putting back through onto the motherboard and then onto the sound card... if you're getting that, unplug the speaker.