Before I get blasted, I chose this forum on purpose, because ultimately this has to do editing 5D MKII video in Premiere. When editing 5D2 footage, if you got stuck having to use that uber-useless internal mic on the camera, right-click the audio track on the Premiere TL and send it to Soundbooth. In SB you can choose Effects-->Advanced-->EQ: Graphic (Advanced). Open Settings and set the EQ to 30 band, and try the setting I have in the image attached. It will HELP the 5D2 sound a good deal, but don't expect a miracle. You can at least get by with this added EQ if you had to resort to the internal mic in a pinch. Play around, you may find a better result with some tweaking.