Guys, I’d welcome advice with a weird sound issue. Thanks if you’ve got five minutes to read :)

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By Oliver (AKA the Admin) on 37 comments
in Categories: Just Talking

My mood when I can't fix hardware problems

Hey guys. Could I trouble you with a request for help, with a technical issue that’s troubling me?

Listen to that.

Around 3 weeks ago, I noticed my USB microphone now had a soft buzzing sound in the background, that wouldn’t go away. Long story short, everything else below that line is that I can’t understand WHY there’s this bug; read on, there’s a mystery to solve :D

That microphone, a Klim My Voice, an USB-plugged microphone, served me perfectly for a year with work, games and skyping, until then, all good.

After the buzzing sound started, I contacted the manufacturer and they sent me a replacement mic… that had the exact same issue. Bad luck happens, but that was starting to be weird. Thus, I ran more tests.

And I noticed that weird thing: the mic buzzes on my desktop, on a new Dell laptop, on an old Dell laptop, at my father in law’s house’s desktop PC, at my desktop that booted a Linux live distro (tested with Ubuntu and OpenSuse)… With ONE exception: when it’s on the laptops, and those laptop aren’t plugged on the AC.

Yep: when the laptop runs on battery, without AC, the buzzing is gone.

And it’s gone in a split second. I tested recordings in which I unplug, replug, unplug, plug the AC back again, and that generated recordings with moments of silence, followed by buzzing, followed by silence, followed by buzzing.

After this, I ran plenty of tests to see if there wasn’t a blind angle to things, if I didn’t overlook things, to rule out possible explanations…
If you want, here’s the list of all I tested:

– Tested the 2 microphones, old and new, in 2 homes, and on 4 PCs. My win10 desktop, my desktop booting OpenSuse from USB, my desktop booting Ubuntu from USB, a new win10 Dell laptop, an old Win10 laptop, and my father in law’s very old desktop with a brand new win10.
In all cases, there was the buzzing, except when it was on the two Dell laptops and they weren’t on the AC but instead ran on batteries.
As the problem happens not just with Windows, but also with Linux, I regret to say it doesn’t seem to be caused by a recent Windows update.
Still, I deleted the mic from the devices manager in Windows 10, let it be reinstalled after a reboot, no change (the manufacturer doesn’t provide drivers for this product, it’s recognized by Windows and works), to no progress.

– There is no fancy effect in the mic’s properties in Windows 10, no noise correction or post-processing (not greyed options, no, no options at all.)

– The Dell laptops have a built-in webcam, recording audio and video, although with a poor audio quality (you hear the laptops’ ventilators and all, bit of a white noise). They record audio without any buzzing at all, with and without AC plugged in. I don’t have another external microphone to test with, regrettably (money doesn’t grow on trees, I’m not going to buy hardware just to run tests).

– The microphones have a “push me right or left” thingy, to adjust their volume. I noticed the volume of the buzzing follows the volume chosen for the mics, faint when the volume is low, strong when the volume of the mics are at their max.

– I gently (and less gently in the end) tried prodding the old mic’s body parts, it didn’t cause any change in the buzzing.

– The USB male and female plugging parts (end of the mic’s wire, part where it goes in the PCs) were thoroughly verified, dusted, multiple USB female plugs were tested, always to no difference in the end result.

– Because why not, I tested with an USB extension chord between a  laptop and one mic, zero difference.

– The buzzing sound was not a software error, it was noticed on Skype (by an annoyed colleague, fuck him),  I recorded it with Goldwave on Windows 10, with the default audio recorder built-in windows 10, and with Linux’s Audacity.

– Could an electric apparel cause electric disturbance affecting the sound recording? I got no technical knowledge to tell, but I’ll highlight I tested it at somebody else’s house (my dear father in law, without whom there’s no fixing broken sinks in the family, may he live very long).
Also, at home, I made an experiment (1) turn off every fuse in the breaker box, save the fuse for one room; (2) confirm the buzzing is present and disappears when I record sound on a Dell laptop and suddenly unplug the AC while it’s recording; (3) turn off that room’s fuse; (4) turn on another room’s fuse, bring the laptop to that room, test the very same situation happens. It would tend to confirm there’s nothing providing interference on the power network.

– I’ll mention the plugs in my home are earthed, as are they at my father in law’s home, the two places in which the tests were ran, so it’s not that kind of problem either. I tested on a non-earthed wall plug, though, and: same problem.

– I was tempted to to try switching (“just in case” ©®™ ) the AC adapters of the new and old Dell laptops, but they’re not the same model, the new one has double the voltage, and I don’t dare risk doing something that could, who knows (me, I don’t) perhaps damage the machine and void the new machine’s warranty.

– On the new Dell laptop, I ran the machine’s system diagnostics tools provided by Dell, and it didn’t find anything wrong.

*


And that’s it, for now, I’m at my wit’s end, I don’t see how else to explain it, and what I may do to fix that problem.

After all, it is possible the old mic simply broke, and the new mic was shipped defective. However unlikely, it isn’t impossible… Unfortunately, that doesn’t explain why the buzzing disappears once I unplug the laptops’ AC, does it?

Would you have an idea, about what may cause that problem?
Thanks if you can help ^^

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Dog
Dog
3 years ago

This tends to happen when the AC grounding is bad – the laptops that arent connected to AC don’t have the problem, right? Google ‘AC ground loop’. Couple of things to try: if the mic is powered, use the same power strip/ outlet as the laptop, get shielded cables for the mic.

oldbrokenhands
oldbrokenhands
3 years ago
Reply to  Dog

This is the right answer. I have this same problem with some cheap ass Harmon Kardon speakers I’ve had for over 20 years. They only buzz when in the presence of my computer monitor.

Poor shielding and EM interference.

NostalgiaGlasses
NostalgiaGlasses
3 years ago
Reply to  Dog

Yeah – the only other thing I could think that could eliminate grounding or ‘noisy’ power issues would be a UPS/battery Backup, since it’s running the juice through some ‘filtering’.

NostalgiaGlasses
NostalgiaGlasses
3 years ago

considering you tested multiple mics and pc’s – it’s quite possibly something new on the power-grid in your area that is making the power “noisy” – possibly a new power-plant or some industrial-size machinery.

USB microphones (ones that plug in VIA a USB cable to the PC for audio – not just power) will *always* have some noise in the sound. It’s possible that you previously had something running a noise cancellation filter (windows settings or sound-card) which had mostly negated the effect.

If a UPS (Un-interruptable Power Supply is the “proper” name in english) doesn’t solve the issue – you’ll likely need to switch to a mic that uses regular audio-port plugs.

Curio
Curio
3 years ago

you can rule out a grounding issue with one of these: https://www.amazon.com/Sperry-Instruments-GFI6302-Outlet-Tester/dp/B000RUL2UU/ref=sr_1_1

and if that’s the problem, and you can’t fix the wiring, something like this might be helpful: https://www.amazon.com/iSilencer3-0-USB-Audio-Noise-Eliminator/dp/B01MXDZ0PO/ref=sr_1_2?dchild=1&keywords=ground%2Bisolator%2Busb&qid=1590028926&sr=8-2&th=1

best of luck man

defiledrealms
defiledrealms
3 years ago

Noise cancellation or post-processing isn’t something to be afraid of, as noise is pretty much constant, meaning it has a fixed frequency (spectrum) and amplitude, therefore its easy to filter after its analyzed. Speech however is a bunch of random impulses both in frequency and amplitude, so it wont be filtered unless the device used is a makeshift.

As the problem is only present when you are connected to AC, its probably the 50Hz (low tone/frequency) from the line that creates the noise. In that case the location (or the grid) doesn’t matter when using the mics.

So invest in something that you will need (and use) anyway, a USB hub or a post processing device, maybe a sound card (there are USB ones). Preferably something that has noise filtering/cancelling. Active is better as it will work its magic on noise only and you will get no adverse effects, unless it breaks, but at some point everything does.

In case you need some background info hit up google with ‘how noise cancellation works’ and watch some youtube videos, they will most likely be about headphones but the point is the tech itself. (I’m not linking to avoid getting spam flagged)

defiledrealms
defiledrealms
3 years ago

Yeah it should be possible to remove the noise through some means of filtering, namely noise cancellation. Sound tech is pretty advanced so even random noise should be no problem.

Oh the sound sample eluded me, but after listening to it its filterable I’d say. The buzzing has a random rhythm but its clearly periodic, feels like a binary code (voltage highs and lows). It definitely isn’t the line’s 50hz noise though, so its not the grid. Its some component’s noise because of the AC. As for which, I have no clue. Can’t be a capacitor charging-discharging.
The motherboard soundcard is not pro enough to filter this effectively unlike a dedicated one.

I’m not 100% sure on the usb hub (I didn’t look into it, shame on me), but as USB is direct current it shouldn’t produce noise. I’m not sure a hub would fix this, but if you need one anyway, its worth a try.

I’m not a sound technician though so I may be wrong. I can only go about it hit and miss style. Still I hope some of my ideas may help.

Try this vid for info on noise cancellation. Its about headphones but the point is the technology.
https://www.youtube.com/watch?v=F7D_pnaexG0

Pavlov
Pavlov
3 years ago

So, check me on this: you’ve used 2 different mics, with and without extension cable, multiple PCs, at least 3 different OSs, at least 2 different drivers, multiple software programs, and both desktop and laptop. None of it makes a difference. But when you take the laptops off the AC, the sound goes away. You’ve tried two different houses and eliminated all other hardware in the house, nothing changed.

Right off the bat, I’m thinking you’ve got line noise from the city power supply. Battery power would of course eliminate that. I get line noise from my car when my mp3 player is plugged in, most noticeably when I accelerate. Do you have a car charger? You can pick up ferrite cores for cheap for the mic line, like for one dollar, or I would assume around one pound in Europe. I have no experience with using them, but that’s what they’re made to do, filter out line noise.

Of course, the big question is why did the noise start? Well, the city might have made changes in the power system. Are both houses you tried in the same city, on the same grid? You might call city power, ask if there have been changes in the last few weeks. Microphones are pretty sensitive, they might pick up new line noise.

Pavlov
Pavlov
3 years ago

Wiki link to Ferrite cores

Might help, might not, costs a dollar. I nearly purchased one of these when I realized my mp3 charge cable already had one and I had the problem anyway.

Danger Stranger
Danger Stranger
3 years ago

I cannot believe I can finally try to help Oliver with one of his issues posts. I am sad for the issue but I believe I can at least give a better understanding of the problem. Below is my intake of what happened to both mics, why the issue is solve on laptops running on batteries and possible ways to fix it (but probably will not be worth the trouble)

First things first, why did both mics “busted”? Well probably due to an over current in the USB port you used mics at your PC (not enough to burn the mic) but enough to damage the diode that rectifies the electrical signal that comes from your mic.

Than why does it solve the issue on Laptops running on batteries? Simply because the current generated by the batteries are “cleaner” and the busted diode is not need to rectify the noise coming from the electrical signal.
I would recommend that you avoid using the defective USB port of your PC, for any new mic of the same brand. If it is a current issue in your entire PC (it happens due to aging of electrical components) your other USB Ports may be compromised.

So, how to fix the busted mics? You could try to “Do it yourself” (DIY) by opening the mic (which would void your guarantee), and change the defective Diode. Another possibility is to send it for repair and ask for a test and change of the defective Diode, but due to the Quarantine status around the world, I do not know if this is a valid option for you. You can also just use the mic in battery mode for the time being and try buying another mic brand and hope for it component to be less sensitivity for electrical over currents.

Hope I could help a bit with my intake of the issue, but it is always hard to give proper feedback without properly manual testing of the parts I believe caused the issue and damage the mics.

Danger Stranger
Danger Stranger
3 years ago

You can also ask for your college to tune down the audio coming from you (I do get it, the noise can be annoying if you keep lessening for a long time, but really, it is tolerable and there are other ways that he can help you out).
Also you can use the function push to talk so that lessens even more the noise issue (it will only appear when you talk, but your own voice will be over it).

Pavlov
Pavlov
3 years ago

Just to clarify what DS is saying, you may only have one USB card in your PC, so if one port is mic-fryingly overpowered, they may all be mic-frying. Sounds like step 1 is check the power level coming off your various devices, see if any of them are too high. That lets you figure if you’ve isolated the cause. Not much point in buying another mic until you stop the mic-killer. You could probably hack a test probe with an old USB cable, an electrical meter, and the specs for USB ports.

Pavlov
Pavlov
3 years ago
Reply to  Pavlov

Check it out, I picked up a new toy today:
Klein Tools USB Digital Meter, USB-A (Type A)

USB multi-meter, $17 US / 15.50 Euro. There’s another model with USB-A & USB-C probes for $30 US / 27 Euro that I didn’t know about, not sure I’d have bought that. Checks volts and amps, you have to plug a device in the bottom to check amps in series (I took electronics in High School for 4 years, some of it stuck!) I watched the amps reading change as my Qualcomm charger cut back the power when my cell phone hit 93%. I’ve only owned it for 20 minutes so I’m not offering this as an endorsement, just saying that such devices are available for a decent price. I’ll buy one for my father for Christmas, he was a licensed electrician and I shop for Christmas 365 days a year!

USB Digital Meter

Pavlov
Pavlov
3 years ago

This thing was probably aimed at professional installers, given that they tell you how far you can drop it without breaking. You might be able to find a home owner model for less, but maybe not. And you’re right, it doesn’t have a good/bad indicator on this. I’m going to have to look around and find out what numbers I’m supposed to be seeing when I plug this thing in. (I installed the outlets, you’d think I’d remember what it said it’s supposed to put out. All I remember is that there were numbers!)

The lure of USB ports is that they’re supposed to auto-magically know what a gadget needs and provide it, so yeah, I can picture a device that automatically puts different loads on the port and determines if the charger is playing nice. You’d have 2 simple lights: 1) Everything is green, or 2) It’s evil, smash this fucker!

I did a rough-count around my house, I’ve got around a dozen different USB charge ports I regularly use at home and in the car. Add 2 more at work. I’m not bragging, that’s probably average-to-high. But until now, I’ve just been trusting them not to fry my various devices. I plan on keep this gadget and checking all my new equipment!

Pavlov
Pavlov
3 years ago

I am learning that the field of USB power supply is far, far more complicated than I ever imagined. I found a website for USB specs (www.usb.org) and there’s at least 195 white papers, specifications, and legal papers on every element of USB you can imagine. I found a document titled “USB Power Delivery” and it’s 586 pages of diagrams, schematics, some programming, and a lot of device communication specifications. It’s been fascinating reading for the last hour but at this point I can confidentally say that I don’t know jack-squat. I’ve got my power bank plugged into my wall outlet’s USB port and at 2.24 amps I can say that it is one thirsty bitch! It’s pushing 2000 mAh an hour into what is basically two D cells and it’s still only at 75% capacity. Is that too high? Well, it’s not on fire, so no. Beyond that, not really sure. Now, according to Socrates, the only true wisdom is in knowing you know nothing, so I’ve definitely got that part down!

I think I’m going to go do some exercise now, then start looking at elf porn for awhile. After, maybe I’ll look around for textbooks on USB specs. What can I say, I’m a renaissance man.

Danger Stranger
Danger Stranger
3 years ago

I am glad I could be of some sort of help.

Regarding this matter, just allow me to say that you do not need to be so much concerned over the USB Port now, since it was probably a chain of bad events that lead to this situation.
A cheaply batch of diode chosen from the microphone manufacture (first event), a lack of low electrical current test over the diode batch (by the manufacture) and the USP port slightly over current that ended killing the diode.

As I mentioned earlier, it is probably the same USB Port that busted both microphones, but for the rest of your daily USB accessories it is probably still usable. Just try to find it out before using a new mic on it, or simply do not buy a USB mic, and buy a P2 mic instead if you have this available port on your computer and you are still unsure of which USB Port it is.

I will and at this, just not to give you a wall of useless test you might not be interest in (I do tend to try to be useful and end up writing to much), but if for some reason you are interest in it, just give me a reply to this post =D

detunizedgravity
detunizedgravity
3 years ago

As someone else said you’re certainly picking up live noise from the AC. As to why both mics have the problem… I would say that this model has a component that dies with time, and that the”new” one could in fact be a refurbished one. Both are old, both have the defect. A burnt diode or capacitor…

One risky way to solve the problem would be to open one mic and try to find and change the damaged component. Another MIGHT be to replace the component by inserting power conditioning between the city line and the PC. A small UPS could do that trick. However, if the mic is actually picking the 50Hz from the line, it probably won’t help much.

B99
B99
3 years ago

clearly this fine community has allready (hopefully) helped you resolve the problem, so let me be the first to say this: This is probably the most distraught-looking cup of coffee i’ve ever seen…

NostalgiaGlasses
NostalgiaGlasses
3 years ago
Reply to  B99

Looks like a Dixie Cup of Dr Pepper actually

B99
B99
3 years ago

maybe? Whatever the liquid tough, it’s making a face like someone who found a bag of drowned puppies by the riverbed :(

profh
profh
3 years ago

Try it with a USB hub.

Bob
Bob
3 years ago

Could be something using the power cables to transmit data or a malfunctioning device creating noise on the outlets loop. Sometimes I’ll use powerline ethernet adapters to fix lolwireless issues, they create an ignorant amount of detectable noise on peripheral sound devices. Something else to check is testing on newly installed electrical work. Doesn’t matter where you are, there’s always places with 50-100yo elecrical going bad.

Asdfb0y
Asdfb0y
3 years ago

Have you tried to see if the sound is still there with the adapter plugged into -just- the computer so it is not connected to the wall. Do you get the sound then?