Fastened audio on overdubbed tracks

Hi all,
I tried to spot if this issue was raised earlier but could not find. Sorry if Im wrong.

Features: Audacity 2.1.0, Win XP. Signal goes through AuidoTechnica condensator Mic (XLR cable) and Lexicon Lambda external USB device.

The problem: When recording second third etc tracks playing the first one at the same time, the record will sound as if the tempo were upgraded (voice higher and faster). The problem do not occur: For the first recorded track AND if other tracks are not played while recording a new one. In the latter case I only mean that box is ticked or not in Settings/Recording. If it is ticked in, the record will be faster REGARDLESS if another track is in fact sounding behind it or NOT. That is why I doubt its a computer issue (memory problem etc.)

Any idea?
Thank you.

If you’re overdubbing, the computer has to play the backing tracks perfectly and record your new track perfectly at the same time. If the computer isn’t up to the stress of doing that, the new track may record badly or slowly which will be fast when played after the performance.

You can produce a fast film by slowing down the movie camera during the performance.

If you’re not overdubbing, the computer will produce a single, fresh, new track every time you press record. No extra stress.

So my first guess is you need a more powerful computer for overdubbing, or strip out any activities the computer may be doing at the same time as your recording. Disconnect the network. Really stop Skype, don’t just leave it napping in the corner, etc.

While the network is disconnected, suspend your anti-virus.


As well as the possibility of the computer not keeping up and missing little pieces, speed problems are as I often say usually a problem of one or more of the following:

  • Mismatched sample rates somewhere between Audacity, Windows and the device
  • Incorrect drivers for the device doing the playback and recording
  • A different device is performing the playback to that doing the recording, and the clock speeds of the devices do not match (it is normal with consumer grade equipment that they would not match).

We have a FAQ ready made for this:

So in your case, have you got the correct latest Lexicon drivers from ? Note that the Lambda does not work on 64-bit XP, if that is what you have.

Also see Important information for Windows XP users about the potential risks of using XP.