latency very strange!?

Hi! I’m using a very fast Windows computer with plenty of memory and all previous versions of Audacity worked fine. I just switched to Audacity version 2.1.2, and no matter how I adjust the latency (using the click track method) it locks all tracks in sync just fine again…for 16 seconds! After 16 seconds, any newer tracks start to fall behind. I’ve tried every adjustment I can think of.

Any suggestions? Thanks!

What version of Windows exactly? Did you update to Windows 10 on the same machine when you updated to 2.1.2?

So you have variable latency, or variable speed recording. Please tell us more about exactly what you are recording using what equipment (makes and model numbers are good).

If you are using Windows WASAPI host in Device Toolbar, perhaps try another audio host. WASAPI in Audacity has a known problem “latency when overdubbing may substantially increase shortly after starting the recording”. See

Also see Why is my new track out of sync with the previous ones, or sounds crackly or at wrong pitch?.


I’ve tried every adjustment I can think of.

…except changing the recording device. I’m going to guess you’re overdubbing using a USB microphone. When you do that, the playback of older or backing tracks is done according to the timing and processes of the computer, but the digital stream from your voice or instrument is made from the electronics inside the microphone.

If you offended the sound gods in some way, those two can be very different and no overdubbing or latency adjustment is going to make up for that. You might be able to fix it in post production with Effect > Change Speed on one or the other track until they match.

I can’t make up my mind which is more likely, a poor quality or broken microphone, or an overloaded computer which can’t keep up. When you’re overdubbing, the computer is stressed. It has to play back all your older backing tracks absolutely perfectly and record your new work absolutely perfectly.

Restart your machine and when it wakes up, stop all processes, jobs and programs that have nothing to do with your show. Do not let Skype nap in the background, for one important example.


Yes, I am using WASAPI. Where could the problem be in that? What should I be using? I see that there is also MME and Windows Direct. In the past (with earlier versions of Audacity) on this same computer, same setup, I’ve used WASAPI with no problems. I thought it might be a problem with 2.1.2 but guess not. I don’t use a mike to the computer but rather the line input. Windows 7 64 bit.

The (potential) problem with suddenly increasing latency has existed ever since we added WASAPI support, but not everyone experiences it all the time.

Generally MME and Windows DirectSound have about the same latency on Vista and later. That latency is higher than what WASAPI should deliver when it behaves. You could redo the latency test using either MME or Windows DirectSound and see if the latency remains stable.