What format are you capturing from? Digital formats have much lower levels than analog sources. Depending on the format a digital peak may be as a low as -10 db.
If you are using an analog source, just go through a mixer and get the levels adjusted there.
With FCP 6 you can normalize right there and save the hassle, it's really worth it.
Jared PicuneIdea Spring Editing, Inc. Denver Final Cut Pro UGGeeky Mac | FCP Tips & Tricks