Batch Volume Processing

I would like to batch process multiple MP3 files for volume control of my music. Audacity seems to be the best tool for this job due to the availability of hotkeys and being able to set volume levels using an absolute input value. I was using Sound Forge Pro V10 but I am unable to adjust volume levels as a direct value. It wants me to use percentages of the current level. Using a direct target is much more convenient.

I would like to start off by saying that I DO NOT want to use replay gain/normalizing. This method does not always work to my satisfaction and I still find myself reaching for the volume knob. When using Sound Forge Pro V10 and I choose to adjust Volume (not Normalize) and I set the volume of the file to say -6.0db for a selection of MP3 files; they all play at very close to the same volume and I don’t have to keep messing with the volume knob on the stereo. Using Sound Forge Pro is clunky and time consuming because I can not seem to adjust to an absolute value, only a relative value based on the current dB level of the file.

How would I go about using Audacity to batch process a group of MP3 files (say 8 to 20) in a folder for setting volume, or Effect|Amplify… in the Audacity software?

I don’t use batch processing but it’s done with [u]Macros[/u]. Someone else can help more if you need it.

As you probably know, MP3 is lossy compression. When you open an MP3 in a “regular” audio editor it gets decompressed. If you re-export as MP3 you are going though another generation of lossy compression and some “damage” does accumulate.

[u]MP3DirectCut[/u] can do limited editing without decompressing (including normalization and volume adjustment). As a bonus, since it’s working on smaller compressed files it can work faster. Note that MP3 can only be adjusted in 1.5dB steps without decoding & re-compressing. (I can’t help you with that either.)

I’m not sure if MP3 Direct Cut can normalize to -6dB, but you could normalize first (regular 0dB peak normalization) and then reduce by -6dB (or as close as it can get +/- 1.5dB) or you could use the same procedure with SoundForge (which also means another generation of lossy compression).

I would like to start off by saying that I DO NOT want to use replay gain/normalizing. This method does not always work to my satisfaction

The only perfect method is to use your ears, and even then two people might not agree. Most commercial recordings are normalized for 0dB peaks but they don’t all sound equally loud. The purpose if ReplayGain is to match the perceived loudness. The popular streaming services also use (perceived) loudness matching.

Thanks for the reply. I’m still not certain what I want to do. Currently I have about 37,000 tracks in my collection. I’ve ALWAYS had issues with perceived loudness and I’m constantly looking for a solution so that when I play a random playlist I don’t have to keep f^*#ing with the volume. The only thing I’ve really learned is; there is no easy solution to this problem.

I was vaguely aware of MP3 being lossy compression but I do appreciate you reminding me that re-exporting is going to cause damage to the file. Also, thanks for the tip with MP3DirectCut. I’ll be checking that out this weekend.

Thanks again.