I have been doing some net surfing concerning adding more insulation to ones subwoofer. I popped the 12" driver out of my PSB Subsonic II to check it out. The inner cavity is divided in two the left side which houses the amp is stuffed with pink fiberglass. The right side is empty with two ports. Would adding poly fiber fill to this area affect to port tuning? A rough estimate as to volume on the right side is 1.3 cubic feet. Thanks.