Audacity Forum

Hello ladies and gents! New Audacity user here, and I'm really enjoying it! Very easy to use, and it's been a lot of fun. However, I can't seem to get rid of distortion during certain parts of a song, and it's driving me crazy! There is NO clipping... I already went through and found some, and I used ClipFix on it. None left. And strangely, if I play each track as a solo, there is no distortion on ANY of them. It's only when I play them all together that I get this horrible sound during the climax of the song. I've tried it using 3 different speakers... I've tried it through my headphone, and amp, my television... the distortion always happens in the same place and I can't get rid of it!

I'm recording using a PreSonus AudioBox 4 and a brand new Rode microphone. Windows 7, Audacity 2.0. Can someone tell me what I might be doing wrong, or maybe let me know what other information you might need to help? It's for a wedding and it's this Saturday so I'm getting nervous. Thanks so much!

Multi-track recording I presume?

When tracks are "mixed" together, the waveforms are "added".
("Mixing" is sometimes referred to as "summing").

Usually, when tracks are mixed, the combined mix of tracks is "louder" (higher amplitude) than any of the individual tracks. You can probably see this happen if you look at the playback meter and compare the level of a "solo" track (click the solo button on the track) and the level when playing all tracks together.
See here for more information about the meters: http://manual.audacityteam.org/manual/h ... olbar.html
(there are some special case exceptions to this rule, but we can come back to that later if you're interested. For now let's just get the wedding CD done )

Tip 1
Resize the meter toolbar to full screen width so that you can see it more easily.

Tip 2
If you alter all of the tracks in a mix by the same amount, then the balance of the parts remains the same.

In order to get the mix level down so that it does not distort you can either use the "gain" sliders on the left end of each track, or use the "Amplify" effect.
The advantage of the Amplify effect is that it is very easy to adjust the levels of all tracks by the same amount.

Tip 3
How to select all tracks at the same time: Press Ctrl+A.

Select all of the tracks (Ctrl+A) then select the Amplify effect from the effect menu.
Try setting the "Amplification (dB)" level to -6 (minus 6), then press "OK".
All of the track waveforms will shrink to half height.
Hopefully this will resolve the distortion problem. If the distortion problem improves but there is still some remaining distortion, or the meters are still hitting 0 dB on the loud parts, reduce the level on all tracks a little more.
Don't worry if the overall volume level sounds a bit too quiet.

Tip 4
Before exporting the finished masterpiece, save the project (so that you can come back to it if you need to, then,
Select All (Ctrl+A)
"Tracks menu > Mix and Render"
This will mix down all of the tracks into a single track.
Now use the Normalize effect and normalize to -1 dB (minus one).

You are now ready to Export your masterpiece.
If you intend to burn it to CD, export in WAV format.
If you intend to load it into an MP3 player it may still be worth exporting a WAV version as a backup copy before you export as an MP3.

Tip 5
If you wish to save the project again, use "Save As" and give the project a unique file name so that you don't overwrite the multi-track version.

Tip 6
Don't delete anything until after the wedding.
Use the "File menu > Check Dependencies" feature before you save your projects to ensure that the projects are self contained. If prompted to "copy in" files, say yes and let Audacity copy them.

Agh, brilliant!! Yes, multi-track recording (piano, violin, viola, cello, and three singers recorded separately). Your trick worked like a charm, thanks! I guess, in a perfect world, the overall mix would be a little louder, but I'm not complaining! The distortion is gone and that makes me happy; I'll do this from now on. Is there another step I could take though, to make the overall volume level louder? Or is that just the price I pay for no distortion? Thanks again!

Amplifying/Normalizing the sound to -1 dB is about as high as you can get without either (a) clipping (distortion) or (b) compressing the dynamics.
Compressing dynamics is commonly used on commercial recordings so as to make them sound louder (see Loudness War http://en.wikipedia.org/wiki/Loudness_war ).

Personally I prefer to retain the dynamics and turn up the volume on the amp, but if you want to try dynamic compression, three effects that can help to accomplish that:
1) The Compressor effect http://manual.audacityteam.org/manual/h ... essor.html
2) This "Limiter" plug-in http://wiki.audacityteam.org/wiki/Nyqui ... ns#Limiter
3) Chris's dynamic compressor http://forum.audacityteam.org/viewtopic ... 42&t=58958

Great, thanks! I'll mess around with the Compressor Effect and see if I prefer using it or not. Interesting reading on the loudness wars too, thanks!