Im not sure what kinda plugins come with Wavelab standard but Im pretty sure you atleast get the steinberg Q.

This can be found under VST plugins. Simply select the "low" button and select your freq range by use of the keyboard or drag the little grey button next to the "Lo" shelf indicator. Drag it around till ya find what your looking for. If you could post a small sample I could better tell ya where ya might wanna start to correct/EQ it.
I used to use some SF back in the day but dont have it loaded so I cant walk ya through that. But the paragraphic EQ in SF will look kinda similar to this

Simply make a shelf or just drag and drop a few freq's till ya find where your muddy sound is. More often than not in AUD taping there is a major low end rumble almost everything below 50-60hz could prolly go.
If ya wanna pm me I would be happy to help if ya have any other ?'s