Problem: I've heard from a lot of people about hum or background 'buzz' in recordings and Skype conversations when using a USB headset (like the one I have, the Logitech USB Headset H350). Almost every time I hear someone having this trouble, they're having the problem while using the headset with a laptop.
Solution: about 99% of the time, the problem is fixed by simply plugging the laptop into a grounded (3-prong) outlet.
On a Mac, if you're using the Apple power adapter without the extra power cable (with a 3-prong plug instead of the 2-prong plug), you may get a buzzing sound. On a PC, different adapters work differently, but hopefully you have a power adapter with a 3-prong plug.
The problem is caused by a well-known phenomena, a ground loop. When you plug in your laptop to a grounded outlet (3 prongs), the circuits for audio in the laptop have a 'ground' signal to make sure the audio doesn't get any interference. Sometimes, if your laptop or a USB accessory is made of metal, you might notice the buzz goes away if you touch a metal part. This is a surefire sign you have a ground loop problem.
With USB headsets, the only way to fix this is to plug your laptop into a grounded outlet. With analog headsets, there are some other ways of fixing the problem by isolating the signal better.
See related: Buzz or Hum in Computer Speakers.
Comments
I wrapped some flexible copper wire around the USB plug, soldered it together, wrapped it around the headset cable, stripped the wire near headset end, made a loop that touches my ear, now the headset uses me as ground. The hum went away.
Innovative idea; do you get a shock when you put on the headset?
No! I've tried this myself but by connecting one end of a wire to the outer metal part of usb plug & put the other end in my boxers!
This doesnt make any shock as it has just 5v 0.5A of electricity
Umm... Couldn't you have tried to locate the other end somewhere a little less... risky?
Please Jeff i need ur help;can u please open ur logitech usb and help me with the wiring combinaition colour??mine got cut so i really need help to fix it,plz. thanks
Sorry, but since mine works well, I'd rather not break it apart at this time :-/
hi Jeff
It's alright Jeff, u can easily unmount the usb plastic cover and then mount it back but since u don't want to take the risk i will just keep mine in d storeroom... I am in a place whereby i can't even think of getting any support assistance to replace it.Or i will just do trial n error!!!!
Thanks for answering.
Ran across this exact situation. The best way on a laptop to test would be to remove the A/C power source and see if the hum goes away. It should go away as the laptop switches to DC battery power. I have, of course, lost the three prong extension cord to the Macbook Pro power adapter. So I'm not sure if that would be the solution. But it makes sense that it would be.
Thanks for posting this.
Using a Logitech headset on an iMac. There is clearly a ground loop here - the hum goes away if I touch the metal casing of the computer or the stand.
Hey thanks, this finally stopped the buzzing. I didn't know the solution could be that simple :)
Well, there are laptops whose power adapters are NOT 3-prong. Not sure what you can do in that case -- except to run on Battery Power....