09-30-2009 11:07 AM - edited 09-30-2009 11:26 AM
Hi, I have been researching a similar problem that my friend is having with her USB headset + laptop.
Looking through a smattering of results from google I've found the following information:
- The humming phenomenon is known as "Ground Loop". It happens commonly with laptops, and many audio devices where people use analogue cables.
- It's caused by the AC power supply in laptops which, when cables/connections are not properly shielded/earthed, creates interference on your microphone/line in. When you unplug the AC power supply & run on battery the hum disappears.
The most common solution suggested was to use a "Ground Loop Isolator", a small box which apparently shields/filters the signal from your audio cables. However, this suggestion was only indicated for people with analogue (3.5mm jack) headsets; and I had the impression that USB headsets (digital as opposed to an analogue signal?) were not susceptible to this kind of interference. The most common solution people give is actually upgrading TO a USB headset =P. Since you and my friend both have USB headsets, I assume the problem is similar, but the interference is happening somewhere other than than the headset?
The other area where there may be a problem is in the sound card - I've read suggestions that some kinds of laptop sound cards may cause this problem.
There are various, complicated (for me at least), suggested solutions like rewiring of power cables, adding transistors and so on which people suggest for other types of audio devices which an electrician specialising in laptops/audio devices might be able to carry out. Apart from the ground loop isolator for analogue headsets, I can't find any other solution for fixing this problem in laptops (other than possibly buying a new sound card, or an external sound mixer).
Some more links of people with a similar problem
**One more solution from an old thread on this Logitech board:" My humming problem was solved after I switched to a grounded laptop adapter (in NL recognized by a round shape instead of an elongated)"
***Though I think it's unlikely your USB headset is the cause of the issue, perhaps your headset is actually damaged (or has a flawed design when used in conjunction with certain types of laptops) & as such isn't properly shielding the audio signal?
This page describes the grounded laptop adapter solution above, and provides a better explanation of the problem. However the first solution involves disabling your laptop's ground, which may not be advisable (a power surge can fry your laptop, apparently).
Here's some more discussion of the problem, someone suggests using an "Inline Surge Suppressor" which I'm trying to find out more about.
10-05-2009 04:06 PM
I have purchased a powered hub and have done as you requested and tried the headset via the powered hub. It has made no difference and might even be a little more pronounced.
I have tried this powered hub test both using the Skype call test and also also using Windows Accessories >sound recorder where the sound waves (when silent with no speech) clearly show the hum as a repeating flat level peak say 2 mm thick and 2 centimeters long followed by a fine and completely flat/level sound line (about the same length of 2 centimeters) as if representing a pulsed sound/hum. (hope this description is helpful).
Any new suggestions?
10-12-2009 03:44 PM
I wish I had a fix for you, but so far we don't have a reliable work around. Asking you to run your laptop disconnected from AC is not acceptable. We are working on it, but I have nothing in the way of a fix at the time.
11-07-2009 03:21 AM
I've got a Clearchat Comfort USB headset, and on every single computer I plug it up to with Windows XP it works perfectly. Any computer with Windows Vista and now Windows 7...background noise, feedbacks, etc. I've stumbled on a funny realization. I was plugging the headset through a USB extension cable like Mike suggested and noticed the buzzing background noise was gone. At first I was jumping for joy, but the moment I let go of the metal part connecting the two cables together the buzzing came back. This is when I realized it's a ground issue. Sadly I have no ground here in Korea, everything is 220v and all two prong without the slightest concept of grounding squat. So I plugged my headset up to the extension cord and ran it just under my desk where I can place my foot on the metal part between the headset plugged into the extension and plugged the extension up and as long as my bare skin touches the metal it's buzz free. This is very depressingly sad because there is literally no concept of grounding stakes and cables in this country whatsoever. So I'll be on the hunt for a metal rod, a copper cable, and a way to bring it into my apartment on the 2nd floor and wrap it around the metal part connecting the USB extension cord and the USB headset cable. You'd figure USB headset's are digital, not analog...thus wouldn't be affected by this kind of thing. And don't even ask me why when plugging the headset up to a Windows XP system doesn't cause this background buzzing garbage...I've tried it on over 50 computers at multiple locations (PC game shops all around the place) and the one's with Windows XP worked flawless, but Windows Vista/7 buzzzzzzzzzzzzzzzzz....
11-11-2009 01:40 AM
I also experience HUM on my Wireless Logitec Headset, and have come to the following conclusion :-
The actual Microphone seems to be feeding an Automatic Level control in the headset. ????
The Windows Mic level control does not seem to have the expected control.
To confirm this, try this test. Use a program that can monitor in "close to real time" your Mic. ( I used Teamspeak in TEST mode).
If you remain quiet for about 10 seconds, you will hear the HUm increase to a given level.
Then make a quick LOUD noise, and then listen... The HUm is gone, but then slowly rises again over about 5-10 seconds.
Sounds very much like some form of AUTOMATIC level control ? ? ?
I found the best way to REDUCE the Hum was to keep lowering the Windows Mic level, till the volume of my voice started to drop.
About at a 20% level. in my case. Any higher, and my Voice as no lounder, but the HUM increased with higher slider settings.
If this is the case, maybe Logitech can comment. It would seem to be a POOR design to have the Automatic level control.
I would far prefer to have had a manual Mic sensitivity control on the headset, or even better, the option to go Manual or Automatic.
However, careful adjustment of the Mic Level can optimize the "Voice/Hum" ratio !!!
( Owner of an older Cordless Logitech mouse that EATS batteries at an alarming rate !!! )
11-11-2009 10:50 AM
11-11-2009 03:20 PM
Hi logi Nu
Thanks for joining in the search for a solution of this problem. I will certainly try out your suggestion regarding using the USB extension lead. I did try this before but it didn't occur to me to hold it to ground it (but then I am nontechie!).
The bad news for me though is all your testing on Windows Vista and Windows 7 machines and finding that the problem does NOT happen with Windows XP. Unfortunately, it is Windows XP that I use, AND\experience the HUM, so I am not sure what this means.
I had more or less given given up on the situation waiting (ever waiting) for Logitech to come up with the final solution - indeed, I live in hope.
11-11-2009 03:30 PM
01-05-2010 09:50 PM
hello fellow logitech headset users i today purchsed a logitech clearchat pro headset and indeed i have a very similar problem people i am talking to hear a significant buzzing/humming noise when using the headset and it is plugged into the power adapter,iff i remove power it works fine.I realy like this headset in all other aspects but this thing is a real nuisance have any of you resolved this issue yet? I am considering returning the headset but iff their is a fix i would like to keep it as i really like the design and durability of it.I have read on a forum somewhere that windows has released a patch to fix the issue but i could not locate after an hour of google searching.