Are sound adjustments 'destructive'—or 'offline?'

Hi Folks,

I’ve started using Audacity to digitise and improve some very old and poor live recordings of my band from cassette.

My question is: when I adjust EQ say, is it permanently applied to the track (destructive) unless I ‘undo?’

If so, does that mean I should duplicate the track—edit it, and keep the original unaltered version in the project window?

In GarageBand for example, everything seems undoable and is just sort of laid over the linked sound assets, you’re hearing a preview with each change. Even chopping a section of music doesn’t chop the original asset.

Maybe Audacity isn’t the right tool for what I want to do?

Thanks :wink:


You should definitely keep a backup copy of all important files.
Note that Audacity does NOT act directly on audio files. When you Import (or “open”) an audio file, Audacity copies the audio data from the file into the Audacity “project”. Audacity is always working on a copy of the data, not on the original audio file.

Hi Steve, thanks for the reply.
So if I get near the end of polishing up the song having eq’d and added reverb, say, and amplified stuff, I can’t go back to and earlier stage and redo eq for example?

I’m assuming that tweaking the eq on the same bit up and down etc., might degrade things.


Assuming that your tracks are “32-bit float” format (that’s the default) then you can do an enormous amount of EQ tweaking without any noticeable (or even measurable) degrading. 32-bit float is extremely precise. To cause noticeable degrading you would need to apply massively extreme amounts of EQ (for example, if you boost a frequency band by several hundred dB and then cut again).

Two things you could consider.

  1. Add reverb to a copy of the track.
    For each track you want to add reverb to, duplicate the track. Apply reverb to that track, setting the effect to 100% wet. Now you can mix in the amount of reverb you want by adjusting the gain of the reverb track.

  2. Use the envelope tool instead of, or along with, the Amplify effect.
    Applying the Amplify effect to get your tracks to have a peak of about -3dB won’t affect the sound quality at all. But when it comes to adjusting tracks in the mix, use the envelope tool to raise or lower sections of tracks or entire tracks. You can go back and edit the envelope at any time.

– Bill

Hi Steve,

What does ‘wet’ mean in this context?

Are you saying that adjusting EQ with the envelope tool is non-pernmanent/non-destructive?


It was Bill that wrote that, not me :wink:

Regarding effects, “Wet” and “Dry” refer to mixing the processed sound with the original unprocessed sound. “Wet” is the processed sound, and “Dry” is the unprocessed sound.

The technique that Bill is describing is that you have two versions of the same track. One track is the audio without the effect (the “Dry” track), and the duplicate copy is the audio with the effect applied (the “Wet” track). You can then adjust the levels of the two tracks, either with the track Gain slider (see: Audio Tracks - Audacity Manual) or via the “Mixer Board” (see: Mixer - Audacity Manual).

Although applying the effect is “destructive”, the track gain slider is non-destructive, so you can go back and change the Wet/Dry mix at any time.

Thanks everyone, for your help :wink: