I opened one of these files in Helium2 which is how I maintained my MP3 database before being introduced to iTunes. Now, when I browse the ID3 tag info, there is a parameter (in the MP3 and not in the iTunes database) called iTunNorm.
Interesting, iTunNorm is the Soundcheck info field.
All my MP3's were ripped with Exact Audio Copy and Lame, I imported them into iTunes (as you did) and let it scan the files for Soundcheck purposes.
None of my MP3's have had the iTunNorm field added to the tags (I checked in Foobar), but Soundcheck still works both on the iPod and on the PC.
Weird, just when you think you have got to the bottom of it iTunes throws you another loop.
This Soundcheck is a complicated process by the looks of it, the trouble is that no-one really knows much about it or about iTunes interaction with the iPod via the database, as Apple like to keep tight lipped as far as I see.
That's why I've been trying to play around with it and see what it is doing but there seems to be no rhyme nor reason to it's adjustments.
filrkaye,
I don't know what is happening with yours, if you imported your CD's using iTunes and then transferred those files to your iPod then it should just be a case of enabling Soundcheck on your iPod for it to work. Bear in mind that Soundcheck is not perfect and some music does still show volume differences.
Do you hear
any difference at all when listening to the iPod and you enable/ disable Soundcheck ??