butters

my cabinet has a 2226h JBl with a 5 inch round port and its long from the factory. Will installing a 6 inch port make it go lower to 30Hz and adding better dampning instead of polyfill. Polyfill isn't much. I'm an upholsterer and I'm going to use cotton batting we use in furniture. I've read use 2 layers on the back and only cover one side of each wall, the guy said he tried everything and this sounded the best.

you say a 6 inch port 2.65 inches long, for a vent, this can't be right. every other info I've read says 7 or 7.5". long for the vent. who actually knows to tune a 2226h down to 30 Hz