Audacity Forum

Hi

I installed the latest stable version of audacity about 2 weeks ago (I'm pretty sure it was the right version, I can confirm after I check tonight), but it seems there was a problem with one of the settings.

I found that the second track was including the first track, unfortunately I only noticed 2 weeks later so I have some ruined recordings which I would really like to get back. When I went looking for the problem I noticed that the option "Play other tracks while recording a new one" was unchecked. I checked it and tried recording again. This gave me the same result as before (as expected). Then I went back to preferences and removed the check, after which it started working correctly and recorded each track separately, I'm not sure if this is a bug or if something just got messed up somewhere (I'm using windows XP).

Now I have 2 recordings, where track 2 has been combined with track one to form a garbled track 2 and track 1 is a clear recording of track 1. Is there any way I can separate these? I still have the audacity projects and I have hope after reading this post http://audacityteam.org/forum/viewtopic.php?f=28&t=3912 where alatham says its possible to separate music from vocal but, since that wasn't the problem in that post, never explains how. In my case I'm trying to separate 2 vocal tracks, I hope that still means its possible.

I hope someone can help. Thank you very much in advance if you can.

Theoretically you may be able to remove some amount of track 1 from track 2, but if you manage to get it work, then you should buy a lottery ticket as your luck is "in" to an extraordinary extent.

The theory is that we need to "subtract" track 1 from track 2.

The first thing that you need to do is make sure that the "sound of track 1 in track 2" lines up exactly with "the sound of track 1 as it is in track 1".

To do this, you need to look for a part of the recording where there is a nice crisp percussive bit in track 1, and at the same place the new sound on track 2 is relatively quiet. Then zoom in very close and use the "time shift" tool to drag the tracks so that they line up exactly. See the peak that I have highlighted in this example: Here it is after I zoom in - as you can see, it is not easy to line them up exactly, but they need to be spot on: You then need to adjust the volume level of track 1, so that it exactly matches the volume level of "track 1 in track 2".
Again, this is virtually impossible to get exact.

Finally you need to use the "Invert" effect on track 1.

If you have got all the previous steps exactly right (extremely unlikely), you will hear that track 1 disappears.
When we stop dreaming and get back to reality, we find that we may be able to reduce the sound of track 1 a little, but not enough to be worth the effort as we just cant's get the waves to match accurately enough.

Thank you for your detailed response.
I tried just after you posted it and have tried again now for quite a while without luck. Unfortunately you are right, trying to get the two to match, especially the volume matching, is pretty much impossible as the waves(?) look slightly different.

Thank you anyway though
No lottery for me this week