Ryan, I bet Jimmy will have some suggestions when he gets there in the morning. If you turn off your pump for 60 seconds, then start it up again, if there was cavitation is should be resolved. There are a few reasons this is happening:
The inlet isn't large enough to get all the water the pump needs.
The rigid PVC pipe is vibrating.
The plumbing is too restrictive.
The pump is just plain noisy right out of the box (so to speak).
There is stuff you can put around the inside of the cabinet to help deaden the sound, but if you have a racket in the fishroom, that is never good. So hopefully we can figure out why this is occuring.