Audio Track Records 7% slow

I’m using the latest version, 2.4.0 running on an iMac and also running the latest version of Catalina 10.15.4.

This just started happening today. About every other voice track that I crash record ends up playing back about 7% slow. I’m able to fix the problem by speeding up the track by 7% (using the Change Speed effect) or by exiting the program and restarting it. I can’t think of any command that would cause an audio track to slow down when playing back. Any other tracks that I import, such as music, are fine.

Any ideas?


I’m using the latest version, 2.4.0

If you really are on 2.4.0, you should upgrade to 2.4.1. 2.4.0 has been withdrawn.


Thanks. I didn’t notice that there was an upgrade. I’ll grab it immediately!


48kHz to 44.1kHz is about an 8% difference. That could be a clue…

A sample rate change/difference isn’t supposed to cause a speed change but sometimes things go wrong.

Are you recording and playing-back through the same hardware? (Such as recording with a USB mic but playing-back through your built-in soundcard?)

Everything is set to 44.1 kHz.

I’m not recording with a USB mic, but I am using an analog to USB adapter to feed the mixer into the iMac. Playback uses the iMac’s internal speakers. However, I’ve been operating this way for years and have never had a problem. That’s why it threw me when it happened the other day.

I have downloaded the new version so we’ll see if that clears up the issue.


I’ve been operating this way for years and have never had a problem.

So what happened in the last bunch of time? Billions of people have started to use Zoom, Skype or other communications, chat or meeting software. Those are famous for changing your sound settings in the background without telling you.

There are also Apps now that insist on a “subscription” rather than straight purchase, and that means they have to constantly monitor you in the background. Adobe Creative Cloud has sound services whether or not you use them.

Inspect your Dock. How many things do you have running? How many icons have the little light or indicator?

iMacs used to have a built-in microphone. What happens if you record a simple track with that and then play it back? Still get the speed change?

Which USB adapter?


All good points, however, generally speaking, the Mac lets the software set whatever sound settings it needs when active. And while I agree that some other software could have made a change, that doesn’t explain why, while using Audacity, the first audio track I record is ok, then the 2nd one isn’t, then the third one is, etc. If an audio setting had changed internally, Audacity should reset it while it is active and it should stay set during that recording session. And I would think that if the internal sound setting is mis-set, then Audacity would record the track wrong all of the time.

I don’t use Adobe Creative Cloud for anything so that certainly isn’t the problem. The only audio recording and editing software that I regularly use is Audacity.

My iMac does have a built-in mic; however, it’s not working properly at the moment due to a “mistake” made by Apple during a previous repair. Therefore, I can’t use it for a test. But again, see my first paragraph. Why should the track record properly sometimes during a session and not other times? That seems like a weird bug of some sort to me and again, hopefully the new release fixes it. I haven’t had time to try it out yet but I will soon.


2nd one isn’t, then the third one is, etc.

Is it “and etc.?” what happens to the next few? Shouldn’t extrapolate on incomplete data.

You didn’t answer which USB adapter you have. We have to build your machine in our imagination and more information is good.


Everything is set to 44.1 kHz.

“Just for fun”, try everything at 48kHz.

A lot of hardware runs at 48kHz internally and then the drivers are supposed to make any required conversions.

One other note.

Audio Track Records 7% slow

If it plays 7% slow, that means it was recorded 7% fast. You get slow motion in a movie by speeding up or “overcranking” the film in the camera.

In this case it may have been recorded, as DVDDoug above, at 48000, too fast, instead of 44100. That’s just a test concept because the numbers don’t work out exact.

There are no conditions I can think of that causes an error like this “when it feels like it.” It would be really good to know if it keeps alternating good, bad, good, bad.

it’s not working properly at the moment

The evil voice over my shoulder keeps insisting I mention that you’re complaining about bad Mac behavior from a broken Mac.