removing the sax/voice on mp3 tracks in Audacity

[c9off]

Following on from Peter's soundclip from John O'Neills Jazz Technique book which has a sax solo played over a backing track. It is very easy and quick to remove the sax thus leaving a pure backing track with no timing assistance (once I've learnt how it goes!!) this is then the next challenge, and of course the final recording will just be 'you'. Initially the track is converted from .wav to mp3.

In this case (and many others including vocals too) open the track within Audacity, it will show 1 song of 2 tracks. Using the dropdown arrow on the alongside the track name SPLIT STEREO TRACK. You will now have 2 songs of 1 track each. Select the second track (click in the left window) then select INVERT from the drop down EFFECT menu. Now you should find that the first track is the backing, and the second is a sax solo! These can then be exported as MP3s again.

Hoping that I have explained in a way you can understand, but if not just ask!

cheers
Geoff

 

[Pete Thomas]

It doesn't quite work like this (and often won't actually work. But sometimes it will - as long as the track is stereo in the first place).

All stereo files have two sides, Left & Right.

What's happing is that when you invert one side of a stereo signal, any audio that is exactly the same on both sides will be cancelled out.

With a stereo signal that means anything that is panned right in the middle should be removed.

Usually the singer or lead solo instrument is dead centre so often it does get removed.

BUT

Often the bass (or other important backing instruments) is dead centre in the stereo image also and so the base will be removed.

Often the lead voice or instrument has effects (reverb, echo) which is different on both sides of the stereo. This will remain as a ghostly sound from nowhere.

So, it might work well, or it might not. Also the resulting out of phaseness has a bit of a disconcerting sound.

 

[c9off]

Thanks for the explanation Pete as I had no idea what was happening in the background. Indeed had I just moved the balance to the left I would have found that it is a split track!!

Foot in mouth come to mind...