Audacity for Mac 2.4.2
Hi! I’m a complete newbie to Audacity and music editing in general. This is my first project ever so I apologise in advance if any of these questions are really dumb. I’m currently making a mashup, so there are a lot of individual tracks stacked on top of one another. None of the individual tracks go over 0db. I normalised everything to -1db, then I used the envelope tool in various places to arrange the sound and also amplify here and there. I then normalised everything again to -3db to leave some headroom for when everything came together.
When I played it back in Audacity I noticed that some parts of the song would occasionally tip the bar over 0db (presumably due to the stacking). I therefore went through and sorted out the problem parts, using the envelope and amplifier tools (to reduce the sound). I replayed everything and watched the bar meticulously the whole way through. It didn’t go over 0db.
When I export to mp3, no problem. However, when I export to WAV, AIFF, etc (I’m using 32 PCM) , there are occasional crackles or pops (I’m guessing this is clipping?). This also happens when I import the mp3 into the movie programme I’m using to make the accompanying video. When I imported the finished WAV into Audacity to check the waves, I noticed that there were red peaks at the crackles. I went back into the original project, looked at the individual problem areas and reduced the sound more with envelope and amplifier. I replayed and checked the bar again. Looked fine, but it’s still happening on export.
Why is this still happening and what can I do to fix it other than just reduce the overall volume of the whole project to leave more headroom? Would the easiest way be to just slide the gain on all tracks over to -1db? Then everything is reduced in the same proportion and I won’t lose any of the tweaking I’ve done with fading in/out, etc.
Many thanks in advance for your help!