interesting article but if it fools your sub into thinking its that much bigger, wouldnt you lose out on SQ? I mean in a sealed box up to .25cu/ft really wont make that much of a difference but they are talking bigger gains then that so it makes me think you would have to lose SQ.
fiberfill gives the impression of a box that's 10% larger than actual size. that's it. extends low end response a bit. doesn't really do anything to increase SPL. what else is there to know? that's about it in a nutshell. if ya want it, use 1lb/cubic foot of enclosure volume.
all i was showing glass was that actual tests werent that cut and dry to 10 percent boost in box size as was thought before his test results show that to not be a hard and fast rule as per spl changle im not sure i agree in every case but I also know you know your stuff.