The short answer is to work with whatever project rate you want, but when you are doing the final WAV export for the CD, change Audacity’s project rate to 44100.
OK, so to see what is going on here:
- In an empty project, set the project rate to 48000.
- Generate a tone: Sine, 1000Hz, amplitude: 0.45, duration: 60sec.
- Now duplicate the track: Ctrl/Cmd+A, Ctrl+D
- Select the second track only and Tracks > Resample to 44100.
- Select the second track and zoom in about a dozen times (Ctrl+1) until you see the individual samples. Notice that these two signals appear identical.
- Now zoom in a few more times. The signals still appear identical, but try dragging slowly to select some audio in both tracks. As you drag you will notice that although the audio is identical, the sample points are at different places.
When you “Export” a project, the entire project is resampled to the Project Rate as necessary. Go ahead, export this project this project to wave. Call the file wav48000. (You can ignore the “mix” warning if you get one). Close Audacity.
Now, open a new project and set the project rate to 44100. Import > Audio > wav48000. Note how the rate in the Track Control Panel is set to 48000 and also that Audacity’s Project Rate is now set to 48000.
OK, so now change Audacity’s project rate to 44100 and export to wav44100. Explore both save files in File Manager/MacOS. Note that the 44100 file is just a tad smaller than the first. OK, bring (Import) both files back into Audacity and note they are identical (except for the sample rate).
I hope this helps. 