Unstable pitch when recording acoustic guitar

I have successfully replaced a mic that didn’t work properly with one that does - an inexpensive USB mic. The sound is clear but when playing back, the recording has seemingly random pitch wobbles, reminiscent of old cassette tapes. I have shut down all the other apps etc running but it makes no difference. I am using windows 10 - updated Dec 2017 on a Lenovo G50 laptop with plenty of disc space and audacity 2.2.0. I can’t find other questions on this so is it a rare occurrence -and is there a cure?

Try increasing your [u]Latency/Buffer[/u].

…The only thing I can think of is that you’re getting buffer overflow so you’re missing little random bits while recording and that’s making it “skip” and intermittently play-back too fast.

Try changing the Audacity project-rate from the default 44100Hz to 48000Hz , ( some recording devices will only work reliably if the Audacity project-rate matches their sample rate ).

Could also try increasing Audacity CPU priority form “normal” to “Above Normal” : that lowers the odds it will be interrupted by other processes running on the computer

Thank you very much for your replies. I have applied both suggestions - changed the sample rate to 48000 and increased the buffer length from 100 to 200 ms.

I have recorded myself playing again and I still find little moments when the pitch wobbles. (It isn’t my playing!) The artifact is in the recording as it can be heard at exactly the same moment again and again.

All other aspects of the recording seem fine - the sound is otherwise clear and precise but I am at a loss what to do with this noticeable wobble. Is there anything else I can try? (BTW - I rebooted the laptop this morning before starting the recording session).

If you attach a sample WAV file with a wobble, 5-10 seconds, that could give us a clue as to the cause.

Here’s instructions on how to attach audio file to a post … https://forum.audacityteam.org/t/how-to-attach-files-to-forum-posts/24026/1

Thank you.

Here is a WAV file of an example. The ‘wobble’ occurs at about 3.75 seconds.

I can hear the wobble & it’s visible on the spectrogram

But I’ve never heard Audacity produce a fault like that.
The only thing I can think of which could alter the pitch like that is Windows audio-driver software, (aka audio-driver).

You previously mentioned you had a USB webcam, that could be fighting your USB mic.
There is a setting on Windows recording devices to make a device the default recording device, that could resolve any conflict between recording devices …

There are alternatives to Audacity, e.g. OCENaudio , if the fault persists with other audio-editing software then it’s a Windows problem.

I have successfully replaced a mic that didn’t work properly with one that does - an inexpensive USB mic.

Except this one doesn’t work so well, either.

What was wrong with the original microphone?

The second longest post in forum history is by Bruno in Portugal. He wanted to record Flamenco guitar on his computer. That was the whole job. 18 forum chapters over three and a half months.

We got it to work, too, and well, but not with the original home-style microphone.


Thanks, Trebor. I appreciate you taking the time with this. I will try the other software and see if that makes a difference.
The previous mic I was using was a webcam. The mic worked perfectly when I last recorded guitar - over a year ago with a laptop running Vista. My new Windows10 laptop didn’t like the webcam so I bought a new usb mic which installed itself in 2 seconds and which I used for the recording I posted. I removed the old webcam from recording devices and have disabled the only other one left (which is built in to the laptop) so I have one default mic which is my new one. Is there a way into a deeper level of the audio-driver software that could lead to a fix for this beyond the right click on the loudspeaker icon?

Thanks kozikowski - I will look for that thread and read through to see if it helps my situation.

I much appreciate the help.


I’m not sure reading Bruno’s thread would help, but I know we went through a lot of sound quality issues with him. Simple recording tasks are not necessarily easy.

The current recordholder is Ian who was trying to present an audiobook from his apartment in Hollywood. That’s the whole job. 39 forum chapters.


Update - well, well, well. I fired up the old laptop running Vista, plugged in the new mic and then disconnected from the internet (antivirus probably out of date) once the mic had installed ok (very fast). Audacity on there is 2.0.5 and it all worked beautifully. I recorded a few pieces with no hint of pitch wobble - in fact it actually sounded better than on the windows10 laptop, but that could be my imagination.

So the immediate problem is solved - I will be able to record the pieces I want to make into a CD for a Christmas present, as soon as I have the house to myself again for a morning.

I am very interested in getting the win10 laptop to run Audacity properly but that might be something for the future. I will keep checking back on here to see if anyone has resolved the issue and in the meantime - many thanks for your help, and Merry Christmas!


So it would seem that it is not the mic, and none of us have seen this problem in Audacity previously, which would suggest that it is something peculiar about that Win 10 laptop.

Have you tried making a test recording with Windows Voice Recorder? (available here if you don’t already have it: Windows Sound Recorder - Official app in the Microsoft Store)

Just another quick thought - have you tried all of the USB sockets on the laptop? I’m not optimistic about it making much difference, but worth a try.

Thank you, Steve. I have tried all the USB sockets - a USB 3.0 and a USB 2.0 - with the same result from each.

As the older Vista laptop is working well, and I can position it at my elbow, it’s actually more convenient to use that for the moment but I would really like to resolve the issue between my win10 laptop, microphone and Audacity if that is where the problem lies.

Oh dear. It turns out that the old Vista laptop with a previous version of Audacity are showing exactly the same problem. I recorded a piece this morning, played it back over loudspeakers and it sounded as if it was recorded on an old cassette recorder with duff batteries - the pitch kept wobbling every now and again. My previous recording which I thought was clean also has wobbles which I hadn’t noticed first time around. I even tried using the old webcam mic - same problem.

Interestingly I have also used MS Voice Recorder and have found exactly the same problem - the pitch keeps being affected in the same way. So I am thinking this is either the usb microphone (not sure how) or a windows problem.

I used a Lenovo G50 running Windows10, Audacity 2.2.0 and Voice Recorder version 10.1710.2861.0
The microphone is a usb CD04 - I don’t know the make.

Is there a software clean-up program that corrects pitch defects - a kind of auto-tune thing that I could use?

That’s a relief for us, as it shows that the problem is not caused by Audacity.

That is odd. My money was on the USB mic being the problem, but it seems like a heck of a coincidence if the mic in your webcam has exactly the same problem.
Perhaps it’s not as big a coincidence as it first appears. Webcam mics are nearly always used for speech, and usually for Skype and similar, where the sound quality is not expected to be great. A brief 1% shift in pitch would probably go unnoticed in a Skype chat.

Are you able to test with a non-USB mic? What about the laptop’s built-in mic?

I’ve never heard of that one, and it seems that Google hasn’t either. Is it a cheap “unbranded” mic from ebay?

Lenovo have website which checks that your driver software is upto date … https://pcsupport.lenovo.com

#1. Create a system-restore-point before running driver update, just in case the update makes matters worse.
System-restore allows you to put your Windows operating-system back to the way it was in the past.

#2. Update all the out-of-date drivers, not just the audio driver, as they can interfere with each other: preferably keep a matching set.

Thanks Steve and Trebor for again taking the time with this.

Steve - the mic I bought from Amazon:

Trebor - I have updated the audio drivers (it required 2 updates), restarted the laptop and although I thought there was an improvement, I am still getting pitch wobbles as before.

I have also tried recording using something called Ocenaudio and saved the file as a AIFF Audio file which opens ok in Audacity for the editing, but the same pitch wobbles happen with that (and I checked before exporting the file - it is happening in Ocenaudio as it is with Audacity recording and Windows Voice Recorder).

Just to be absolutely sure it is not my playing somehow creating this, I recorded just an open string repeatedly plucked. It was fine in the room, and on replay the second pluck wobbled like a tape recorder slipping - no finger on the string so it wasn’t me!

When updating the Lenovo G50, the process got stuck so I may go back and try again to update everything that I can.

Thanks again.

Have now completed the updates for the Lenovo G50. I recorded 20 seconds of me repeatedly playing just an open E string. The recording has 4 clear pitch wobbles…
So I’m stuck!