when i mouse over my files ripped using eac and lame 3.97, why does it have a track gain field saying -4.7db for example while the same file ripped with dbpoweramp12 doesnt. isnt this bad for gapless albums when the gain has a different value for different songs within the same album? it wont be fluid. whats up with this? i never noticed this before cause i never saw so much info come out of a mouse over on a music file until i installed dbpoweramp.

i did not check the normalize box on eac so why is this so???

You didn't normalize these files at all, they were scanned using ReplayGain in Track Gain mode instead (LAME only supports this mode). "--noreplaygain" in the command line should prevent LAME from calculating the gain during encoding. You can safely add it since most audio players expect the ReplayGain information to be found either in ID3v2 or APEv2 tags anyway. And yes, the different Track Gain values destroy the intended dynamics between an album's songs, that's what the so-called Album Gain was introduced for. The latter sets the loudest song's gain to 89 dB, the others are scaled by the same value to make sure that the dynamics between them are preserved. In your example, if the track you mentioned had been the loudest one then the other songs' Album Gain values would have been -4.7 dB as well. ReplayGain scans including both types of scanning can be done using MP3Gain or foobar2000.

I'd recommend using Album Gain for all your albums since it spares you the pain of having to modify the volume every time you switch between different albums. Ever had the problem that your ears were about to explode when your portable player's shuffle mode chose an extremely loud, overcompressed song of 2006 after you had just been listening to a well-mastered 1987's one?

Besides, there's no reason to delete your encodings just because of the unwanted ReplayGain informations. The files themselves haven't been modified in any way, LAME just added a small tag containing the Track Gain value in the header. Your playback software won't mind this tag in any way as long as it isn't explicitly told to do else.

I used to think the same thing, but technically it is not correct. Replaygain scans the entire album to determine the gain which is different than basing the gain from the scan of the loudest track.

That would fit the observations I made from comparing some albums' highest Track Gain values to the Album Gain ones in the past. What does the latter actually do then? Calculate the gain based on the average volume of all songs? E.g., if we had 4 songs of 98 dB, 95 dB, 93 dB and 90 dB, would their Album Gain be -5 dB based on a calculation of (98+95+93+90):4=94? From reading the documentation this isn't quite clear to me.

It takes the 95th percentile of the sorted array of the data taken from the entire album.

in laymans terms, what does all this have to do with the files levels when played through an ipod for example since it has only been written in the tag and not made a change in the file itself? is this where ipods sound check feature comes in or what? pls explain this using real world daps and players and what settings make these tags activate

The ReplayGain tag tells the decoder how much louder/more quiet the track has to be played back compared to its original volume level. For most portable players this tag is of no interest at all since it's not read anyway, just a few software players and rockboxed DAPs are able to handle ReplayGain. Winamp and foobar2000 allow the handling of these tags in their "Playback" options, you can set them either to use Track or Album Gain as well as a Preamp there. The Preamp allows global volume modifications to all RG'ed files since the reference value of 89 dB is sometimes too quiet for today's speakers.

Edit: The Preamp thing applies to foobar2000, Winamp only offers a Preamp for non-RG'ed files under "Playback". Use the equalizer's Preamp in order to globally modify the volume level in Winamp's case.

Exceptions to this are MP3Gain and foobar's converter, which allow manipulating the audio stream itself instead of just setting a tag, hence every player uses the adjusted volume during playback. Note that the latter applies this change during encoding, making it irreversible. In general MP3Gain is the recommended software for ReplayGain scans since it allows making both reversible changes to the stream and fully hardware-compatible volume adjustments.

The iPod's Soundcheck feature is technically very similar to this thing, though it's only available as Track Gain - based on statements made on these boards, I haven't ever used an iPod and iTunes myself. I'd say don't bother 'bout it, MP3Gain should be the better option since it works for every alternative player as well.

bingo! thanks thats all i needed to know