Of course I'd want the Album Gain values (that would be overwriting the Soundcheck) to be in a form that iTunes/iPod could use. It would be especially nice if the utility was automated and could convert my entire library with a minimal amount of my input. I considered using AACgain, but I'd prefer not to change the volume levels on the files themsevles (and instead only change the SoundCheck tags). I suspect I'm not the first person to want this and was hoping I could learn from other people experiences.

If you don't want to change the files themselves with AACGain, which can be undone, than try a ReplayGain scan with foobar2000 and copy the values for the albumgain section to the tag part of the soundcheck.

Myself, I have had no problems with AACGain (using Mp3Gain frontend) and I use its AlbumGain feature on all my Nero AAC encoded audio files. Since it can be undone if I really need to have it undone for some reason. Also, it allows me not worry about soundcheck or anything as I just pop the file and go.

Simply copying the values isn't going to work. You need to convert them first. foo_dop and mp3tag should be able to do this and there may be other utilities as well. I think you'll have to replace the the track gain values with album gain values first, but I'm not completely sure.

Some links I just found:
http://www.hydrogenaudio.org/forums/index....showtopic=24620
http://www.hydrogenaudio.org/forums/index....mp;#entry514497
http://www.hydrogenaudio.org/forums/index....mp;#entry476698

You can do this with MP3tag. Just Replaygain scan the AACs with foobar or Winamp. Extract the following actions to C:\Documents and Settings\<accountname>\Application Data\Mp3tag\data\actions. Load em up in MP3Tag and right click on the file >convert>action> check the box of the type pf gain you want converted to Soundcheck (Album or Track, AAC or MP3) and hit OK. Now the Replaygain info has been stored in the ITUNESNORM field which an Ipod reads as a Soundcheck value.

EDIT: However, if these AACs have already been run through Itunes and had soundcheck values written, then those tags will have to be deleted in MP3Tag first, then run the above procudure. Load up all the AACs in MP3Tag>select all>right click>extended tags>highlight ITUNESNORM TAG>click red x to delete

EDIT2: To check your work, check and write down the replaygain value for a couple of tracks, open Itunes, make sure Soundcheck is turned on, play one of the converted files, right click>Get Info>Volume should match the Replaygain value you wrote down.

Another possible utility that I found that works in conjunction with iTunes is iGain. Just google up iGain and you will find it and it uses AACGain as its calculation tool.

This is interesting, Gow. Thanks for finding it.

One think worth noting in the context of this discussion that I found in the help file:


Also, it seems that iGain uses AACGain/MP3Gain to adjust the data rather than just calculate Replaygain values.

On the Mac, iVolume uses replaygain to calculate either track or album values, and then applies those values to the ITUNESNORM tag so that it works exactly as iTunes and iPods expect.

I use this and it is fantastic.

I have now succesfully RG all my mp3's and converted the album gain numbers to Soundcheck in mp3tag. I then cleared out my iTunes library and reloaded everything and resynced to iPod.

I now want to check the RG values in iTunes using the method described in the above post. It says I should turn Soundcheck on in iTunes. However, I am concerned that if I do this (it will be the first time I have done it) that it will go away and recalculate all the soundcheck values again and overwrite the ones that were populated in the ITUNESNORM comment from mp3tag. Will this happen, if not how does iTunes know not to do it? If it does happen how will I know its happening?

Regards

Actually, you need to have Soundcheck turned on before you add the media to the library. Itunes won't recalculate the Soundcheck value if there is information already in the ITUNENORM field that it understands. When you add the media to your itunes library, take note of the window on top. It should process album art and them gapless info but should not show a Soundcheck process.

Thanks for providing these actions. I'd been meaning to do all this and your info moved me forward. A couple of thoughts. Not sure about AACs, but with my MP3s I've tested so far, I did NOT have to remove the existing soundcheck value that was in the ITUNESNORM comment tag. Simply running the action to convert soundcheck to album gain on the file (with the existing ITUNESNORM value) seems to have worked (when I check file info within itunes, it has the new (different) value for soundcheck that matches the album gain). This is true even though the existing mp3 file was already in the itunes library (I didn't remove and readd the file to the itunes library).

This said, I also experimented with using the mp3tag action to turn album replaygain into soundcheck values for files that have never been added to itunes. The ITUNESNORM value was added by mp3tag with the correct replaygain value, and when added to the ITUNES, it shows up perfectly without ITUNES replacing the soundcheck value with any newly determined (by itunes) value. Bottom line is that it seems I can use the mp3tag action to convert to album replaygain on either existing itunes library files (without having to remove and readd to itunes library) or before I've ever added to ITUNES.

Am I missing anything here? I'm about ready to run my 50,000 mp3s through this procedure... I'm looking forward to being able to leave soundcheck turned ON in my IPOD when playing live concerts. The itunes souncheck was always just fine for mixing lots of tracks, but if I didn't turn it off, the transition from one song to another in a live concert (even with gapless) was jarring as the volume adjusted automatically. Now Soundcheck can be ON whether listening to live concert or a true mix playlist. Thanks!