Hi i would like to build a 12in sub im fairly good at wood working but pretty much a newbie at tuning and figuring out size. i plan to use a 500w plate amp and would like it to reach down to 20hz is will be for music as well as HT and help with box size and port tuning will be greatly appreciated. the room is a family room kitchen combined so i would have to guess it is 17 X 35 thanks in advance for your response. Woofer recondmendation would also be appreciated and size wise the smallestest i could go and get down to 20hz at least 100db