Static noise with multiple USB microphones


I’ve been having trouble recording clean audio for the longest time. I’ve tried a Blue Yeti and various other USB microphones, but they all have the same result. I am on a shoestring budget, otherwise I’d buy the correct equipment, but I believe it should be possible for me to record audio that is much better than what my setup is currently capable of.

This has actually carried on over a full PC upgrade, so my components are totally different from when I initially had the problem. I’ve tried moving the microphone around the room, but that also doesn’t seem to change the audio. I’ve uploaded a clip to DropBox so you can hear:

I should mention that the microphone is plugged directly into a USB 2.0 socket on the motherboard, and that I’m using Windows 7 - although I doubt that matters. Is there something straightforward I can do to fix this? I’d like eliminate the problem at the source, rather than using filters to strip out the noise.

I can make it better (attached) but it will be a struggle to make Audiobook Standards if that’s what you’re asking.

The original clip is very badly damaged. The first clue is the serious DC offset. See the blue waves have a little “up” at about the 1/4 second mark. That’s not supposed to be there. Look at my blue waves and that push upward isn’t there because I removed it, but I can’t gracefully remove the sound damage that comes with it.

my components are totally different from when I initially had the problem.

But the same motherboard. Any chance of trying a different computer? I think there’s something wrong with the USB system. I’d be guessing, but I suspect the USB 5 volt battery system isn’t at 5 volt and the Yeti is struggling to keep its electronic head above water. That’s hiss or hash, by the way, not static.

My clip was three different filters. Effect > Normalize: Remove DC, Normalize to -3; Effect > Equalization: Custom Voice Filter; Effect> Noise Removal.

If you carry Noise Removal any higher, you’re going to get crashy voices. It’s not a permanent solution.

So, no, I agree. It’s not supposed to do that at all.

USB microphones are widely considered the Get Out Of Jail card for the low-end reader or podcaster, but they don’t work on every computer.


That’s not good - the waveform is offset vertically:
It should be centred on the line at 0.0:
Is that a totally un-edited recording, straight off the mic? If it is then the mic may be faulty. Can you try the mic on a different computer?

Hi guys,

Thanks a lot for the replies. Just to clarify, this is actually a different motherboard, but the result is the same. I actually don’t know what USB mic this is right now (I’m visually-impaired so I can’t see the model number on it), but the result was the same with the Yeti. The recording is also completely unedited. What does it mean for the waveform to not be centred in my case? Perhaps a better question would be: what does it actually mean when it’s not centred? I have actually tried this in a different computer, and the result is the same (for multiple mics).

Ah, so you can’t see the pictures that I posted either - I’ll try to describe what is happening.

For the first third of a second of the recording there is absolute silence. Then the microphone recording starts and there is a “click” at that point.
The waveform should be a wiggly line that oscillates up and down, centred around the mid point of the track, but in the left channel the waveform has jumped up about 10% higher than the mid point, and the right channel has jumped down by about 10% of the track height. It is that sudden jump that causes the click. The displacement away from centre is called “DC offset”, and that usually indicates a hardware fault (though I have occasionally seen DC offset caused by bad drivers).

Do you still have the Blue Yeti microphone? If you do, could you post a similar audio sample made with that.

Hi again,

I’ve actually managed to fix the DC offset within Windows itself, by doing the following:

  1. Right-clicking the volume control → Recording devices.
  2. Double-clicking the microphone → Enhancements tab.
  3. Selecting the Low Frequency Protection checkbox and clicking OK.

Here’s a recording with the DC offset fixed:


I just want to say thank you for your description of what’s going on. I actually can see things on the screen without a problem, as I’m able to enlarge what elements I need to on here. Can’t do that with model numbers :wink:, but I really do appreciate you taking the time to type that out. It’s nice to come across someone willing to go beyond the norm to help me with my disability; I really wish there were more like you - thank you. :slight_smile:

You didn’t really “fix” the problem, you just instructed windows to add low-cut filter to the input chain which will remove the DC offset.

The fact the microphone seems to have that offset to me indicates that there is something wrong with the microphone.

Oddly your second clip also no longer has the high-pitched whine that was in the first clip, did you change anything else between the two clips?

Either way the noise level is still pretty high, and as Koz says, it will be a struggle to get it to audio book standards with post-processing.

Alright, that makes sense. I didn’t actually change anything else with that clip - I just assumed that enabling the enhancement fixed the high-pitched noise. I guess I’ll have to buy a proper microphone then. Would you agree?

Just what I was about to say :slight_smile:

A lot of effort goes into making Audacity as accessible as possible to all.
In case you’re not aware of it, there is a mailing list for visually impaired Audacity users called “audacity4blind” FreeLists / Audacity® recording software and how the Blind can use it
It’s quite an active little community on that list, and some of the users there are very knowledgeable about Audacity, and in particular about accessibility issues.

What are you using at the moment?

Hi Steve,

Sorry for the late reply, I ended up being quite busy yesterday. I’ve switched back to the Blue Yeti to try it again, but the result is the same as before, although the DC offset is fine with this without enabling the enhancement. I’m guessing that whatever the issue is it’s going to present itself no matter what USB microphone I choose to use.

Also, like I said before, I do appreciate you taking the time to help me with regards my disability, so thanks again. :slight_smile: I’ll be sure to check all of the information out.

I’m much more concerned with the lack of problem repeatability. Developers call those “Moon Phase Problems.” When the moon is quarter full and the temperature is above 20C, something evil happens—and only then.

The problems didn’t go away. They’re just resting.

The fact the microphone seems to have that offset to me indicates that there is something wrong with the microphone.

And I would agree with you if we didn’t experience “bad microphones” that clear up when the computer was changed. Mid and low range USB microphones are a total slave to the quality of the USB service. If the five volts in the connector isn’t five volts or in some other way has something wrong with it, I’m not shocked that the microphone has DC offset and noise. If I was drowning or suffocating, I’d have DC offset, too.

It’s very concerning if you changed the computer and the problem persisted. And persisted with more than one USB microphone.

I think you may have sailed beyond first level maintenance from multiple time zones. You need somebody to arrive with a known good computer and a known good USB microphone. Make them good coffee (or tea depending on time zone).

“OK, this microphone is broken, that computer has bad USB…”


Actually, I’m a software developer myself so I know this only too well. (I’m looking at you, race conditions.) A long time ago, I tried switching cables, tried a few different computers and hardware within my current computer in order to diagnose the problem without success. If anything, that’s why this has stumped me for as long as it has. With what you’re saying about the 5v connector, I could, theoretically, just be really unlucky with the computers I’ve tried the microphones with.

I’ll start saving up for some proper audio equipment and try that instead. I don’t really see what other option I have. Thanks for all of the help you’ve provided - it’s been very informative.

I’d still be interested to hear the Blue Yeti sample.

And also keep in mind your shiny new mixer and microphone system is going to have to get into the computer… wait for it … via USB.

The only way to avoid that, past a FireWire connection, is to record on a stand-alone recorder such as the Zoom or Tascam equipment. There is one poster cranking out Audiobook quality work with a Tascam and a quiet room. She cuts it in Audacity, but shoots it with the computer off.


Hi guys,

Sorry for the delayed response. Here’s a sample of my Blue Yeti, although I didn’t realise how far I was away at the time, but I don’t think it really matters.

Forgive my ignorance when it comes to audio equipment, but I assumed the way things would work is you’d end up with an input device that would take those big jacks that guitar amplifier cables have. I thought that’s how a non-USB microphone would be connected. I didn’t realise it would still use the USB, in which case I have no idea what I could do, other than buying a new motherboard and hoping to have one that actually has a high-quality 5v connector on it. The idea of pot luck doesn’t really appeal to me, though.

In terms of actually getting the signal into the computer USB is a good choice. It means the critical (and noise sensitive) analog bits can be away from the electrical noise of the computer case. It’s downside is that it can’t go more that 15’. (Which can be an issue if the computer is a noise source).

This forum as seen lots of issues with the all-in-one microphone and USB interface units, particularly with noise. On paper the Blue Yeti looks like a very nice product, and I would expect it to have a signal to noise ratio that is much much better than what you are getting, but I will note that I’ve been all over their web page and the Blue Yeti user manual and I do not find any specification anywhere for the noise level of the microphone. The Blue Yeti does has a gain knob (something a lot of USB microphones lack) which also in it’s favor. I measure the background noise in the clip you posted at ~-56 dBFS, which is not very good (and not going to meet the ACX requirements) and it doesn’t sound like it is coming from the environment.

Question: where is the software gain control set? (Accessible either through the windows control panel or on the top bar of the Audacity window) I would expect that for a device like the Blue Yeti you would want to set that to 100% and then use the gain control on the microphone to get the proper level. You might try making several test recordings at several settings of the gain control on the mic from all the way down to all the way up. (With the mic in as quiet an environment as you can muster – maybe put the microphone inside a foam and blankets filled box). If the noise level varies with the gain knob then we know it is inherent in the microphone preamplifier.

“those big jacks that guitar amplifier cables have” are called “Phone Plugs” (because they were invented for telephone switchboards) And you will find microphones with that sort of connector but they are not all that common any more. Professional (and professional wannabe) microphones use XLR connectors which even bigger and have 3 pins on the microphone side that mate with 3 sockets on the mixer/amplifier side.

If you are going to go with traditional analog microphones the usual advice from these pages is to invest in a small mixer like the Peavey PV-6 that Koz favors either with a built in USB interface or with a separate USB interface like the Behringer UCA-202. But there are dozens and dozens of USB intefaces and small mixers out there so I will admit trying to choose can be a bit bewildering.

it doesn’t sound like it is coming from the environment.

No, it doesn’t. Analysis of the noise can be informative because noises have signatures. That’s why a common requirement for sound performance submission (including ACX) is a short segment of “Room Tone.” That’s where you sit in front of the microphone absolutely stock still and hold your breath for several seconds. I use two or three. You don’t have to turn purple.

Best operation of Effect > Noise Removal tool requires this short segment.

Yours is “rain-in-the-trees” hiss noise typical of microphone amplifiers. Oddly, not the actual microphone. Most of them make very little noise, but they all have to go through amplification to make them useful and the amplifiers make noise. Your noise is a little odd because it’s muffled. Normal amplifiers give a sharper higher pitch noise.

Obviously if the neighbor’s dog turns up in one of these segments, the solution is pretty straightforward. There was a recent posting where I could almost give you the name and model of the computer just from the fan noise. This is where separating a USB microphone from the computer is a serious problem. No long USB cables. Sorry.

But USB connections may not be entirely blameless in this process. There is a noise I call Frying Mosquitoes. Listen when I stop talking.

That’s caused by an interaction between USB connection noise and USB microphone amplifiers—such as the one inside all USB microphones. Manufacturers can filter that out. All you need to do is throw money, precisely what budding audiobook producers don’t want to do.

This microphone amplifier whines.

This one doesn’t.

Getting the ACX Noise number to work and hit Peak (overload) and RMS (loudness) is rough. If you start out life with a noisy performance for almost any reason, it’s an uphill struggle.

We can’t take the dog out of your monolog. Sorry.


Hi again,

These replies have been very informative - thank you. That recording was actually done with the gain knob set to 0 and the level in Windows set to 50. What I’ve found is the Blue Yeti is incredibly sensitive, so I had to turn the gain right down. In fact, the first time I made a recording with it, it picked up the sound of my sister sneezing downstairs which I’d not heard at all. I wish I still had that clip, but I deleted that a long time ago along with a lot of other test clips I made. They basically do share the same property of the noise level not really fluctuating, at least not enough to be audible to me. Audacity might say otherwise, but it seems to be the same deal. The gain knob was initially in the middle when I received it, but I tried various combinations with the gain and level settings to no avail.

When it comes to purchasing equipment, thus far, I’ve tried to work on a budget, in the hope that I could get the desired quality without the cost. However, this is preventing me entirely from doing what I want to do. For that reason, I am prepared to spend the money (once I have it) for equipment that would allow me to produce clean audio. At this point it seems best to return the Blue Yeti.

That said, I’m a little confused with the two pictures you’ve shown. Are you simply suggesting that getting better quality equipment, despite it still being connected via USB, could solve the issue?

Jury’s out on the USB noise thing. It seems that if you have enough processing in your USB device, the noise isn’t a problem. There is a recent posting of someone using a Shure X2U and easily passes noise, but I don’t know how much processing they did because they didn’t post the raw capture. ACX apparently has been recommending the Blue Icicle as a digitizer/amplifier.

We know both the Icicle and the X2U have significant internal processing because they both supply 48 volts Phantom Power to a microphone that needs it. The battery in a USB is 5 volts. Power processing is the only way to get there and that may be the secret.

The other way to make this work is not use either the computer or USB. There is a poster doing very nicely with a Tascam stand-alone recorder, and another poster, tired of the odd and magic sound quality problems setting up to do something similar.


By “gain knob set to 0” you mean the knob on the yeti is all the way down (turned counter clockwise to the stop)?

If the Yeti is as sensitive as you say I would start to suspect Windows as the culprit. I had a personal experience where I connected a known good USB interface (a Behringer UCA-202) and initially the gain was WAY too high. I downloaded the drivers from Behringer and installed them and magically the levels were fine. I suspect that the issue was Windows was applying a gain boost in software (hidden and independent from the channel gain control). This lifts the inherent quantization noise of the 16-bit data to an unacceptable level.

Note that I’ve plugged this same UCA-202 into many other computers without this issue occurring so it is very difficult to tell what happened. It might have been a consequence of some older sound card driver left over from previous use of the computer or something.

Do you have any friends or associates with a non-windows computer (eg a Mac or Linux box)? If so it might be worth the experiment of plugging the Yeti into a different box and doing a test recording.