How to lower DB

Audacity 3 Help Forum Windows
1

Hi, I’m trying to lower a decibel level (db) of an mp3 file I have here, I would like to lower it by default so it can load in other programs with the same decibel level, How to do this ?

and is there any way in audacity to check the db level of the file opened in audacity ? i can’t see anywhere where to do that.

2

“dB” is a much misunderstood way of measuring things. It is a comparison of the “size” of two things relative to each other, where the “things” are usually signals or waveforms.
Typical uses of “dB” is audio are:

  • Sound pressure level
  • RMS level of a signal relative to full scale
  • dBFS: Peak level of a signal with reference to full scale
  • Weighted RMS level of a signal relative to full scale

“dB” is also used to compare arbitrary signal levels. For example, one might say “signal A has a peak level 6dB greater than signal B”, which is a way of describing the ratio of the levels of the two signals. If the peak level of signal A is 6 dB higher than the peak level of signal B, then that means that the peak level of A is 1.995262 times greater than the peak level of signal B.

One could say;
“I’m going to reduce the peak level of this waveform by 6 dB”,
which means:
“I’m going to amplify this waveform by -6 dB” (note that the minus sign means to reduce the level),
which means
“I’m going to scale every sample value by a factor of 1.995262”,
which means:
“I’m going to multiply every sample value by 0.501187”.

3

Edit → Amplify can be used to boost or reduce volume. Enter a negative Amplification value to reduce the volume.

Note that the MP3 will be decompressed when you open it in Audacity. If you save it (Export) to MP3 again (or other lossy compression format) you are going through another generation of lossy compression. You may, or may-not, notice a loss of quality but it’s something you should be aware of.

There is a program called MP3directCut that can do volume adjustments and some other limited editing without decoding the MP3.

There is another program called MP3Gain which you can use on your entire music library to match the volumes. It also works without decoding the MP3. Or, some players support ReplayGain and Apple supports Sound Check. (Since many quiet-sounding songs are already maximized/normalized and cant’ be boosted without clipping, these volume-matching applications tend to reduce the overall volume of your music library.)