That depends on whether your MP3 files are already tagged correctly with ReplayGain values or not. Some ripping programs do it automatically, some don't. However ReplayGain is not quite the same as normalisation. Normalisation is generally an 'on the fly' adjustment process, which tweaks the volume dynamically as a track progresses. It makes the quieter passages louder and the louder passages softer, which changes the music from the intended studio mix. ReplayGain on the other hand finds th