Correcting wrong recording length[SOLVED]


I’ve recorded a classical concert with 2 deferent recorders (one in the choir behind the orchestra, the other in front the soloists and the orchestra) and when want fuse them in Audacity, I remark that they don’t go exactly at the same speed. So, when I synchronize both records at the beginning, they are very fast desynchronized…That is really problematic!!! (and ugly!)
Anyone has a solution? That will be great! The recorders are not so good, and the sound is not really good, but this record is important for me.

Thank you!!

Audacity 2.03
Mac OS 10.8.3 / Macbook Pro 15"

PS: I’m french, so if I’ve done some mistakes, don’t blame me!

There is no automatic method. Assuming the pitch is also wrong on the track that recorded too fast or slow, you can try an extremely small Effect > Change Speed on the track that is incorrect.

If you first of all open Effect > Change Tempo and enter the required length of the track that would make it the same length as the other track, you can read in the “Percent Change” box the approximate percentage change needed. Then cancel Change Tempo, open Change Speed and apply the percentage change that you noted in Change Tempo.


Yes it’s work!!! I’ve done with “Tempo”.
Thank you!!

OK. If it sounds that the stereo is too “wide” when you mix together, you could try Change Speed instead. It would be more expected that if the recorder was too fast or slow, it would also be recording at the wrong pitch. If that was true, Change Speed would correct the pitch as well as the tempo.

Change Tempo would try to keep the same pitch when correcting the tempo. In doing that, it may inevitably create some distortions.