...the problem is in the original recording and it's really hard to correct....You'd really need to insert an equalizer into the center channel and adjust the midrange controls, which might help,
I use JR Media Center and a EQ Plug-in that lets you set a custom +/- 12dB over 10 bands for each track (if you want) and I've tried to reduce the impact as as follows....
http://yabb.jriver.com/interact/index.php?action=dlattach;topic=54101.0;attach=1332;image but you may have to live with it.
So it seems, all I can do is reduce the impact....still sounds terrible on all but the Car FM Radio.....
Thanks
Nathan