I read a great post about it here; http://integra.cyberglobe.net/caraud...ces/fiberfill/ but still have 2 main questions about pollyfill. 1.It is my understanding that you can make the box "seem" larger that it is by stuffing it. Lets say I have a PORTED box that is 5 cu ft. I need it to be 6.25 cu ft. for optium performance but don't I don't want to build a bigger box or have a bigger one in the corner of my house. I could fill it with 5lbs pollyfill (1 lb per cu ft) and will play / seem like a 6.25 cu ft. box correct? 2.Do I port the box according to the 5 cu ft. size or the new 6.25 cu ft size? For example a 4" port would need to be 12" long to be tuned to 21hz in a 5 cu ft. box , where as in a 6.25 cu ft box it would only need to be 9" long. It would seem more logical to use the 6.25 size and go with the 9" port but I though I would run it by the higher powers to be here on the forum Thanks Guys!!!