On another messageboard I was having an arugement with another member. He said: "and it isnt a sealed box. its ported its 3.5 cubic feet. the port is 12inchs high,4 inchs wide and very long" He was refering to a custom enclosure he designed for a lightning audio subwoofer. Now he said the design was flat from 15hz to 50hz. This is a 12" driver with 10mm xmax btw. I told him for a tune of 15hz he would need a 13 foot long vent. He then responded by saying he had the port snaked around the enclosure, but didnt respond to my question of vent length. My question is, why would someone want to do something like that? The vent being 13 feet long MUST cause pipe resonances. Second, the enclosure must be HUGE, the port would be many times larger than the actual internal airspace. What other disadvantages are there to having such a long vent? Thanks!