To make volume a sinch...just use the line tool and draw a line acrossed the opening into the port so you can highlight just the airspace portion of the enclosure (basically take the line tool and outline the area you want to calculate) and right click, go to info on the section and it'll tell you how many sq feet of area it is and then simply devide the height (in inches) by 12 to get feet and multiply the two to get your airspace for the space //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif