I think that I want to try the added mass to my bastard 418-8H II A8 clones, (but cheating with a graphic equalizer goes a long way to the bass junkie fix I want) and I have the math linked around here somewhere, just can?t link up with my too busy engineer son to run the math. What is that metal ring, copper wire, gold painted steel coat hanger? This 418 has no cooling venting front or back, I wonder if I need to cut out a quarter sized hole through the aluminum dust cover first, then glue on a 416 paper vented dust cover over that, and then add the wire ring, adjusting the wire gauge to fit the mass needed? Just how accurate does the added mass have to be, calculated weight of glue and actual globbed on are two different things?