Level out Audio Levels to -6db for wedding

I am editing a wedding and the priest is all over the place when he speaks. He is up one minute and the next he is low.

Is there a filter that either FCP X already has or a 3rd party filter that when applied, will get his levels, or anyone else's levels, to -6db or close to it without it going over?

Also, the music recorded at the reception is the same way. High then Low. The DJ is very loud when he speaks. I am looking for a way to even it out to -6db.

Thanks

FCP X 10.2

Mac Pro

10 GB RAM