Playback garbled on track 2 or higher.

Using Audacity 2.0.3 on a laptop running Windows 7.
I have an ongoing problem after I record the first track. When I overdub a second track the playback is garbled. I am not over driving the recording program… in fact after recording the first track it plays back clean and good. It does this even if I back off the recording instrument way low. I was using a small mixer with USB, then recently bought a USB interface hoping that would solve the problem. IfI record track 2 AT THE SAME SETTINGS AND SAME INSTRUMENT ETC, the play back is garbled. It kind of sounds like the two tracks are fighting each other on playback.

Please update to the current version of Audacity:

The most likely cause is that your computer is struggling to record and play at the same time.

Avoid using a USB hub.

Try switching between “MME” and “direct sound” as the “host” in the device toolbar. Is one better (or worse) than the other?

Try changing the default sample rate from 44100 to 48000 (“Effect menu > Preferences > Quality”). Does one work better (or worse) than the other?

Avoid running other programs at the same time.

Ensure that there are no scheduled updates occurring while you are recording (for example, Microsoft update, anti-virus updates, defragmentation programs …)

Other suggestions here:

Even more suggestions here: (this page is old. Some parts will be out of date now).

To clarify: It’s not garbled WHILE i’m recording the second track, it’s garbled when playing back track 1 and 2 together. so the computer shouldnt be struggling to record and play at the same time.

How do you know that the audio data for track 2 is not garbled when it written to disk, until you play it?

If you record track 2, and then delete track 1 (click on the [X] in the top left corner of the track) and then play track 2, is it garbled?

well… good question! But my test yesterday was with the identical instrument, input settings, output settings on the instrument. Why would track two recrding go in garbled with identical settings and everything?
Basically I recorded some chords with a guitar on track one, didnt touch anything and recorded some fills and lead on track two. PS: the input never got close to clipping either time.
I’m going to go and try deleting track one and see if track two plays back clean in a few mintues.

OK results from checking per your suggestion:
Deleting track one and playing back track two: track two is still garbled
Re-recorded doing the solo/fills on track one and rhytym/chording on track two (opposite of previous) Track two is still garbled.
All the peaks on the active DisplayGraph(?) are under +/- .5
The I Re-recorded track one with the volume on the instrument up further so that the peaks are at about +/- 1.0. Result: still no garbling
Playback with a new track two over the above: garbled still.

It just seems to be realated to recording any track after track one.

When you record the first track, audio data is coming into the computer via the audio interface (your USB sound card).
When you record the second track, audio data is coming into the computer via the audio interface (via USB) and audio data from the first track is being sent out from the computer via the audio interface. For the second track the computer has to handle the incoming data and the outgoing data both at the same time. That is twice as demanding on the computer as just recording the first track.

There are tell tail signs that can show if this is what the problem is. If you could post a short sample (just a couple of seconds) from track 2 in WAV format of the garbled audio, then I’ll show you the tell tail signs (assuming that this actually is the problem). If this is not the problem then we need to look elsewhere for the culprit.

See here for how to post an audio sample: