A few quick questions:

1) I previously had my entire collection run through mp3trim (1.81) for normalization... after much reading, I am seeing that I will prefer replay-gain setting instead. Can I simply run the entire collection through a replay-gain and have it properly "take away" the old mp3trim normalization? Or, do I need to somehow "remove" the mp3trim normalization first? (Do they save the gains into the same place, so that replay-gaining will overwrite the mp3trim data?)

2) Winamp (5.531) claims to support replay-gain internally - is this the same as MP3Gain's process? Should I replace it with a "better" externally-sourced Replay-gain plugin instead of using the built-in one, or just use external MP3Gain software?

3) If anyone knows: What does the Winamp Internal Replay Gain set volume to? (There is no config to set the db?)


Thanks in advance...

1) Looks like mp3trim may be working just like mp3gain when modifying the amplitude (i.e. modifying the scalefactors). As such, processing it with mp3gain first (at the default of 89db), and then scanning with replaygain (for replaygain aware players) could be the best solution.
Anyway, i read in their info that you can restore the gain with mp3trim too, if you know the gain you applied (which may not be the case).
Please, do some tests before doing it in your whole collection.

2) Winamp supports Replaygain. Mp3gain does not need any support by players, since it modifies the files.
The settings for using replaygain are in preferences, General preferences - Playback.
You can also use it to calculate the replaygain for files selecting them, pressing the right mouse button and clicking on Send to -> Calculate Replaygain.
You don't need any 3rd party plugin, really.

3) There's no slider to set the gain for replaygained files. This implies that they are played at the default db of 89. If you want to increase the value, you have to use the equalizer gain (and then change the slider for non-replaygained files by the opposite amount).

That won't matter if you do not care for replaygain album gain. After mp3gaining individual tracks, the tracks will need no further correction. Additional replaygain tags will just say that a 0dB correction is needed.

[edit]Sorry for my oversight: the following applies only if you are able to "undo" the normalization of mp3trim (or if that normalization was also album-based, but then you probably know what follows already)[/edit]

If you do care for replaygain album gains (you probably should), then make sure that you apply *album gains* as oposed to track gains during the "mp3gain step" (using the terminology of JAZZ). This will adjust the volume of tracks of a same album in the same way according to the "average" loudness of the album instead of that of the track. When you apply replay gain tags after that, track gains and track/album peaks will also be calculated, and you will have the choice when using a replay gain aware player.

My recommendation had in mind playing it with portable players (where mp3gain is better than using replaygain), and replaygain to tell replaygain-aware players that this track is replaygained and not apply non-replaygained gain. Also, mp3gain works in 1.5dB steps. Replaygain has no such limitation.

Ok, sounds like replay-gaining on top of my mp3trim normalization should be ok. So far, many songs are being reduced in volume by around 8db.

I realize album-gain is probably the more audio-phile way to go, but since I don't listen to albums completely, I think track-gaining will be good enough for my needs (often on a motorcycle with a helmet headset, or at the gym - both on an iPod mini!)

Thanks for the quick answers - I will let Winamp do the replay gaining (it seems to be fine on the tracks I have used so far) and leave it at that.