I have searched and searched this topic, with no real clear answer, as to which is the best method of what I am trying to achieve.
Basically I have been trying to find out the best way to individually edit a folder full of trance music tracks in mp3 format to a equal volume so there’s no clipping, and so some of the tracks are not way too loud.
I only use 320kbps CBR, and edit them in 32-bit float 48000hz
I want to do this without losing any noticeable audio quality, like Bass/High Hats etc, whilst still keeping the quiet sections of a track and not making the whole track one volume throughout. And keeping the differences between the the left and right channel as they were intended to be.
I originally thought that amplify was the best option, but have also heard that i should normalize? Then I have heard about compression which baffles me too?
I have a quiet extensive library I need to sort out that I have collected for years, and don’t want to mess it up? As a lot of the tracks are irreplaceable.
You have probably seen this question many times, so apologies for that but I just need it to be clear which is the best option.
Try [u]MP3Gain[/u]. It does loudness matching losslessly.*
Audacity (or any regular audio editor) decompressed the audio when you open the file so you are going through another generation of lossy compression, and the damage does accumulate. You may not notice the quality loss after the 2nd generation but it’s something you should be aware of. (AAC is MUCH more immune to damage from multiple compressions.)
but have also heard that i should normalize?
Normalization is a volume adjustment for peaks at a certain level, usually “maximized” at 0dB. Peak levels do not corelate well with perceived loudness so if you normalize all of your files they won’t all sound equally loud. Most commercially released music is already normalized, including many quiet sounding songs.
Then I have heard about compression which baffles me too?
Dynamic compression (different from file compression like MP3) makes loud parts quieter or quiet parts louder. Typically, it’s used to boost the overall/average level without boosting/clipping the peaks to make it louder overall.
I have a quiet extensive library I need to sort out that I have collected for years, and don’t want to mess it up? As a lot of the tracks are irreplaceable.
Back-up your files! With Audacity you can simply export to a different folder instead of overwriting the original file. But MP3Gain alters the “original” file. It’s theoretically reversible, but I’d recommend backing-up no matter what!
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It works pretty well but it’s not perfect for a couple of reasons. Loudness algorithms are not perfect (two different people might not agree when two or more songs are “equally loud”. Some songs can’t be boosted enough without clipping. (Most songs will be reduced in volume.) And, MP3’s can only be adjusted losslessly in 1.5dB steps.