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View Full Version : Volume Normalize vs. Replay Gain?



kdq
02-07-2008, 11:24 AM
Does it make sense to use both at the same time? Does it matter which mp3 player one uses to play back as to which, if not both, are used?

xoas
02-07-2008, 12:03 PM
Others may differ and there may be exceptions, but in general the answer to the first question (in my opinion) is "No." The Volume Normalization DSP will male permanent changes to the audio on each track it is applied to. These changes cannot be undone, but they will be recognized on any player capable of playing the file.

The ReplayGain DSP writes information to the tag of the audio file which will instruct the player on how to adjust the gain on playback. This information can only be read by players or programs that can read this tag information. In players or programs that cannot read and process this tag information, there will be no gain adjustment at all. There may be some players that might decide that the ReplayGain tag information makes the audio file corrupt and lead the player to fail to play the track. If you convert a file with ReplayGain to a different format (say from FLAC to MP3) the ReplayGain information will have to be re-calculated using the ReplayGain DSP or the ReplayGain tag information will, I believe, be discarded by default (since the adjustments will be different from one file format to another). Volume Normalization will stick with the audio file forever and will be carried over if you convert from one format to another.

There is also a program called Mp3Gain which applies Normalization that will be read by any program but also writes tag information to allow the adjustments to be undone. This tag information may cause some difficulties in reading the file for some players. This repersents a kind of compromise.

Hope this helps you.
Best wishes,
Bill