Just keep in mind that if you put a roundover on the inside of the port, and then roundover the outside edges, that bottom peice of the port will not come out to be very round depending on what size roundover bit you plan on using. If very small it will be fine but if its something like a 3/4" then it will be rather pointed. Personally I would roundover everything except the inside of the port opening. Thats what I did for my subs and it came out very nice.