mp3/wma/aac tracks playback with unequal volumes

[zor]

Here's my problem. I have various tracks from various albums ripped to various formats (mp3, mp4, and wma). I'm not quite sure why but some of these tracks play much louder than others and it doesn't seem to correspond with the particular format used either. (I did apply volume levelling on the wmas so that may have screwed things up, but some aac tracks play much softer than others)

Anyway, I'm playing these back on the PS3 which plays everything just fine except that I need to change the volume on my receiver every time a track comes up that's a lot softer or louder than the one before it!

Is there any solution to this? I don't think the new receiver I'm getting (sony str dg820) will be of any use and I don't see how any receiver could be of any help. I'm guessing the only thing to hope for is a PS3 firmware update. Help!