Hi, I’ve been using Audacity, including the Amplify effect, for many years, and recently upgraded to 3.1.3. I think I found a bug. Here are the steps to reproduce the problem I’ve run into lately (not always, just sometimes):
- Select all (the entire project is just a single stereo track, around 3 hours, Split into multiple sequential clips)
- Effect > Amplify…
- Notice the suggested Amplification (dB) is something much less than expected, e.g. -0.045 (since New Peak = 0.0, this implies clipping somewhere, right?)
- Cancel out of the Amplify effect
- Effect > Limiter
- Type: Hard Limit
- Input Gains (L&R): 0.0
- Limit to: -8.00
- Hold: 10.00
- Apply Make-up: No
- Click OK
- Now, try the Effect > Amplify… again
- I would expect the default Amplification to be something closer to 8 dB but it has not changed, still -0.045. So, I go looking for the peak (If there is there a way to ask Audacity where the peak is, I haven’t found it; there are no red vertical lines anywhere in the track to indicate clipping)
- Cancel out of the Amplify effect
- Select the first 22:00 minutes of the waveform
- Effect > Amplify…
- The suggested Amplification is different but still very low, e.g. 0.973
- Cancel out of the Amplify effect
- Select the first 11:00 minutes of the waveform
- Effect > Amplify…
- The suggested Amplification is 7.966 (as expected, given the -8 dB Limiter above)
- Cancel out of the Amplify effect
- Select the next 11:00 minutes (11:00 to 22:00) of the waveform
- Effect > Amplify…
- The suggested Amplification is 1.205 (shouldn’t it be 0.973?? This is why I say it’s a bug.)
- Cancel out of the Amplify effect
- Ignore the data and press on! Effect > Amplify…
- Enable Allow Clipping
- Amplification: 6.0 (why not, given the -8.0 Limiter above)
- Click OK
- Look for red clipping lines (none found)
- Effect > Amplify…
- The suggested Amplification is -3.61 (the saga continues)
- Cancel out of the Amplify effect
Please let me know if I need to clarify anything.